X-Git-Url: http://nitlanguage.org

diff --git a/c_src/string._sep.c b/c_src/string._sep.c
index 0e3294a..095c6a0 100644
--- a/c_src/string._sep.c
+++ b/c_src/string._sep.c
@@ -1,58 +1,26 @@
 /* This C file is generated by NIT to compile module string. */
 #include "string._sep.h"
-void string___AbstractString___output(val_t p0){
-  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+val_t string___AbstractString___items(val_t p0){
+  struct {struct stack_frame_t me;} fra;
   val_t REGB0;
-  val_t REGB1;
   val_t tmp;
   fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
   fra.me.file = LOCATE_string;
-  fra.me.line = 151;
-  fra.me.meth = LOCATE_string___AbstractString___output;
+  fra.me.line = 26;
+  fra.me.meth = LOCATE_string___AbstractString___items;
   fra.me.has_broke = 0;
-  fra.me.REG_size = 2;
+  fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[1] = NIT_NULL;
   fra.me.REG[0] = p0;
-  REGB0 = TAG_Int(0);
-  /* ./../lib/standard//string.nit:154 */
-  while(1) {
-    REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
-    /* ./../lib/standard//collection//array.nit:23 */
-    if (UNTAG_Bool(REGB1)) {
-    } else {
-      fprintf(stderr, "Uninitialized attribute %s", "_length");
-      fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-      nit_exit(1);
-    }
-    REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
-    REGB1 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB1));
-    /* ./../lib/standard//string.nit:154 */
-    if (UNTAG_Bool(REGB1)) {
-      REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
-      /* ./../lib/standard//string.nit:155 */
-      if (UNTAG_Bool(REGB1)) {
-      } else {
-        fprintf(stderr, "Uninitialized attribute %s", "_items");
-        fprintf(stderr, " (%s:%d)\n", LOCATE_string, 155);
-        nit_exit(1);
-      }
-      fra.me.REG[1] = ATTR_string___AbstractString____items(fra.me.REG[0]);
-      REGB1 = TAG_Char(UNBOX_NativeString(fra.me.REG[1])[UNTAG_Int(REGB0)]);
-      /* ./../lib/standard//kernel.nit:327 */
-      printf("%c", (unsigned char)UNTAG_Char(REGB1));;
-      REGB1 = TAG_Int(1);
-      REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB1));
-      REGB0 = REGB1;
-    /* ./../lib/standard//string.nit:156 */
-    } else {
-      /* ./../lib/standard//string.nit:154 */
-      goto label1;
-    }
+  /* ./../lib/standard//string.nit:26 */
+  REGB0 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 26);
   }
-  label1: while(0);
+  fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[0]);
   stack_frame_head = fra.me.prev;
-  return;
+  return fra.me.REG[0];
 }
 val_t string___AbstractString_____bra(val_t p0, val_t p1){
   struct {struct stack_frame_t me;} fra;
@@ -68,15 +36,14 @@ val_t string___AbstractString_____bra(val_t p0, val_t p1){
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
   REGB0 = p1;
-  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//string.nit:28 */
+  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 28);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 28);
   }
   fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:585 */
   REGB0 = TAG_Char(UNBOX_NativeString(fra.me.REG[0])[UNTAG_Int(REGB0)]);
   /* ./../lib/standard//string.nit:28 */
   goto label1;
@@ -84,30 +51,6 @@ val_t string___AbstractString_____bra(val_t p0, val_t p1){
   stack_frame_head = fra.me.prev;
   return REGB0;
 }
-val_t string___AbstractString___items(val_t p0){
-  struct {struct stack_frame_t me;} fra;
-  val_t REGB0;
-  val_t tmp;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 26;
-  fra.me.meth = LOCATE_string___AbstractString___items;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 1;
-  fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[0] = p0;
-  REGB0 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//string.nit:26 */
-  if (UNTAG_Bool(REGB0)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 26);
-    nit_exit(1);
-  }
-  fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[0]);
-  stack_frame_head = fra.me.prev;
-  return fra.me.REG[0];
-}
 val_t string___AbstractString___substring(val_t p0, val_t p1, val_t p2){
   struct {struct stack_frame_t me; val_t MORE_REG[2];} fra;
   val_t REGB0;
@@ -127,82 +70,88 @@ val_t string___AbstractString___substring(val_t p0, val_t p1, val_t p2){
   fra.me.REG[0] = p0;
   REGB0 = p1;
   REGB1 = p2;
+  /* ./../lib/standard//string.nit:38 */
   REGB2 = TAG_Int(0);
+  /* ./../lib/standard//kernel.nit:213 */
   REGB2 = TAG_Bool(UNTAG_Int(REGB1)>=UNTAG_Int(REGB2));
   /* ./../lib/standard//string.nit:38 */
   if (UNTAG_Bool(REGB2)) {
   } else {
-    fprintf(stderr, "Assert failed");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 38);
-    nit_exit(1);
+    nit_abort("Assert failed", NULL, LOCATE_string, 38);
   }
+  /* ./../lib/standard//kernel.nit:215 */
   REGB2 = TAG_Int(UNTAG_Int(REGB1)+UNTAG_Int(REGB0));
+  /* ./../lib/standard//string.nit:39 */
   REGB1 = REGB2;
+  /* ./../lib/standard//string.nit:40 */
   REGB2 = TAG_Int(0);
+  /* ./../lib/standard//kernel.nit:212 */
   REGB2 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB2));
   /* ./../lib/standard//string.nit:40 */
   if (UNTAG_Bool(REGB2)) {
     REGB2 = TAG_Int(0);
     REGB0 = REGB2;
   }
-  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB2)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//kernel.nit:214 */
   REGB2 = TAG_Bool(UNTAG_Int(REGB1)>UNTAG_Int(REGB2));
   /* ./../lib/standard//string.nit:41 */
   if (UNTAG_Bool(REGB2)) {
-    REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
     /* ./../lib/standard//collection//array.nit:23 */
+    REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
     if (UNTAG_Bool(REGB2)) {
     } else {
-      fprintf(stderr, "Uninitialized attribute %s", "_length");
-      fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-      nit_exit(1);
+      nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
     }
     REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+    /* ./../lib/standard//string.nit:41 */
     REGB1 = REGB2;
-  /* ./../lib/standard//string.nit:41 */
   }
+  /* ./../lib/standard//kernel.nit:212 */
   REGB2 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB1));
   /* ./../lib/standard//string.nit:42 */
   if (UNTAG_Bool(REGB2)) {
+    /* ./../lib/standard//kernel.nit:217 */
     REGB2 = TAG_Int(UNTAG_Int(REGB1)-UNTAG_Int(REGB0));
+    /* ./../lib/standard//string.nit:43 */
     fra.me.REG[1] = NEW_Buffer_string___Buffer___with_capacity(REGB2);
     /* ./../lib/standard//string.nit:44 */
     while(1) {
+      /* ./../lib/standard//kernel.nit:212 */
       REGB2 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB1));
       /* ./../lib/standard//string.nit:44 */
       if (UNTAG_Bool(REGB2)) {
-        REGB2 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
         /* ./../lib/standard//string.nit:45 */
+        REGB2 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
         if (UNTAG_Bool(REGB2)) {
         } else {
-          fprintf(stderr, "Uninitialized attribute %s", "_items");
-          fprintf(stderr, " (%s:%d)\n", LOCATE_string, 45);
-          nit_exit(1);
+          nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 45);
         }
         fra.me.REG[2] = ATTR_string___AbstractString____items(fra.me.REG[0]);
+        /* ./../lib/standard//string.nit:585 */
         REGB2 = TAG_Char(UNBOX_NativeString(fra.me.REG[2])[UNTAG_Int(REGB0)]);
         /* ./../lib/standard//string.nit:45 */
         CALL_abstract_collection___Sequence___push(fra.me.REG[1])(fra.me.REG[1], REGB2);
+        /* ./../lib/standard//string.nit:46 */
         REGB2 = TAG_Int(1);
+        /* ./../lib/standard//kernel.nit:215 */
         REGB2 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB2));
+        /* ./../lib/standard//string.nit:46 */
         REGB0 = REGB2;
-      /* ./../lib/standard//string.nit:46 */
       } else {
         /* ./../lib/standard//string.nit:44 */
         goto label1;
       }
     }
     label1: while(0);
-    fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
     /* ./../lib/standard//string.nit:48 */
+    fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
     goto label2;
   } else {
     /* ./../lib/standard//string.nit:50 */
@@ -213,6 +162,7 @@ val_t string___AbstractString___substring(val_t p0, val_t p1, val_t p2){
       once_value_3 = fra.me.REG[0];
       register_static_object(&once_value_3);
     } else fra.me.REG[0] = once_value_3;
+    fra.me.REG[0] = fra.me.REG[0];
     fra.me.REG[1] = fra.me.REG[0];
     goto label2;
   }
@@ -234,35 +184,31 @@ val_t string___AbstractString___substring_from(val_t p0, val_t p1){
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
   REGB0 = p1;
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//kernel.nit:212 */
   REGB1 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB1));
   /* ./../lib/standard//string.nit:61 */
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Assert failed");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 61);
-    nit_exit(1);
+    nit_abort("Assert failed", NULL, LOCATE_string, 61);
   }
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//kernel.nit:217 */
   REGB1 = TAG_Int(UNTAG_Int(REGB1)-UNTAG_Int(REGB0));
-  fra.me.REG[0] = CALL_string___AbstractString___substring(fra.me.REG[0])(fra.me.REG[0], REGB0, REGB1);
   /* ./../lib/standard//string.nit:62 */
+  fra.me.REG[0] = CALL_string___AbstractString___substring(fra.me.REG[0])(fra.me.REG[0], REGB0, REGB1);
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
@@ -289,53 +235,50 @@ val_t string___AbstractString___has_substring(val_t p0, val_t p1, val_t p2){
   fra.me.REG[0] = p0;
   fra.me.REG[1] = p1;
   REGB0 = p2;
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
+  /* ./../lib/standard//string.nit:71 */
   REGB2 = TAG_Int(1);
+  /* ./../lib/standard//kernel.nit:217 */
   REGB2 = TAG_Int(UNTAG_Int(REGB1)-UNTAG_Int(REGB2));
+  /* ./../lib/standard//kernel.nit:215 */
   REGB0 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB2));
-  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//string.nit:73 */
+  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 73);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 73);
   }
   fra.me.REG[2] = ATTR_string___AbstractString____items(fra.me.REG[0]);
-  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[1])!=NIT_NULL);
   /* ./../lib/standard//string.nit:74 */
+  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[1])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 74);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 74);
   }
   fra.me.REG[1] = ATTR_string___AbstractString____items(fra.me.REG[1]);
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//kernel.nit:214 */
   REGB1 = TAG_Bool(UNTAG_Int(REGB0)>UNTAG_Int(REGB1));
   /* ./../lib/standard//string.nit:75 */
   if (UNTAG_Bool(REGB1)) {
     REGB1 = TAG_Bool(true);
   } else {
+    /* ./../lib/standard//kernel.nit:214 */
     REGB3 = TAG_Bool(UNTAG_Int(REGB2)>UNTAG_Int(REGB0));
+    /* ./../lib/standard//string.nit:75 */
     REGB1 = REGB3;
-  /* ./../lib/standard//string.nit:75 */
   }
   if (UNTAG_Bool(REGB1)) {
     REGB1 = TAG_Bool(false);
@@ -344,18 +287,21 @@ val_t string___AbstractString___has_substring(val_t p0, val_t p1, val_t p2){
   /* ./../lib/standard//string.nit:76 */
   while(1) {
     REGB3 = TAG_Int(0);
+    /* ./../lib/standard//kernel.nit:213 */
     REGB3 = TAG_Bool(UNTAG_Int(REGB2)>=UNTAG_Int(REGB3));
     /* ./../lib/standard//string.nit:76 */
     if (UNTAG_Bool(REGB3)) {
+      /* ./../lib/standard//string.nit:585 */
       REGB3 = TAG_Char(UNBOX_NativeString(fra.me.REG[2])[UNTAG_Int(REGB0)]);
       REGB4 = TAG_Char(UNBOX_NativeString(fra.me.REG[1])[UNTAG_Int(REGB2)]);
-      REGB5 = TAG_Bool(IS_EQUAL_OO(REGB3,REGB4));
       /* ./../lib/standard//string.nit:77 */
+      REGB5 = TAG_Bool(IS_EQUAL_OO(REGB3,REGB4));
       if (UNTAG_Bool(REGB5)) {
       } else {
+        /* ./../lib/standard//kernel.nit:347 */
         REGB4 = TAG_Bool((REGB3)==(REGB4));
+        /* ./../lib/standard//string.nit:77 */
         REGB5 = REGB4;
-      /* ./../lib/standard//string.nit:77 */
       }
       REGB5 = TAG_Bool(!UNTAG_Bool(REGB5));
       if (UNTAG_Bool(REGB5)) {
@@ -363,22 +309,27 @@ val_t string___AbstractString___has_substring(val_t p0, val_t p1, val_t p2){
         REGB1 = REGB5;
         goto label1;
       }
+      /* ./../lib/standard//string.nit:78 */
       REGB5 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:217 */
       REGB5 = TAG_Int(UNTAG_Int(REGB0)-UNTAG_Int(REGB5));
+      /* ./../lib/standard//string.nit:78 */
       REGB0 = REGB5;
+      /* ./../lib/standard//string.nit:79 */
       REGB5 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:217 */
       REGB5 = TAG_Int(UNTAG_Int(REGB2)-UNTAG_Int(REGB5));
+      /* ./../lib/standard//string.nit:79 */
       REGB2 = REGB5;
-    /* ./../lib/standard//string.nit:79 */
     } else {
       /* ./../lib/standard//string.nit:76 */
       goto label2;
     }
   }
   label2: while(0);
+  /* ./../lib/standard//string.nit:81 */
   REGB2 = TAG_Bool(true);
   REGB1 = REGB2;
-  /* ./../lib/standard//string.nit:81 */
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
@@ -398,9 +349,9 @@ val_t string___AbstractString___has_prefix(val_t p0, val_t p1){
   fra.me.REG[1] = NIT_NULL;
   fra.me.REG[0] = p0;
   fra.me.REG[1] = p1;
+  /* ./../lib/standard//string.nit:88 */
   REGB0 = TAG_Int(0);
   REGB0 = CALL_string___AbstractString___has_substring(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1], REGB0);
-  /* ./../lib/standard//string.nit:88 */
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
@@ -421,26 +372,23 @@ val_t string___AbstractString___has_suffix(val_t p0, val_t p1){
   fra.me.REG[1] = NIT_NULL;
   fra.me.REG[0] = p0;
   fra.me.REG[1] = p1;
-  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB0)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
   REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
+  /* ./../lib/standard//kernel.nit:217 */
   REGB1 = TAG_Int(UNTAG_Int(REGB0)-UNTAG_Int(REGB1));
-  REGB1 = CALL_string___AbstractString___has_substring(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1], REGB1);
   /* ./../lib/standard//string.nit:94 */
+  REGB1 = CALL_string___AbstractString___has_substring(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1], REGB1);
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
@@ -458,8 +406,10 @@ val_t string___AbstractString___to_i(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:100 */
   fra.me.REG[0] = CALL_string___Object___to_s(fra.me.REG[0])(fra.me.REG[0]);
   fra.me.REG[0] = CALL_string___String___to_cstring(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:596 */
   REGB0 = TAG_Int(atoi(UNBOX_NativeString(fra.me.REG[0])));
   /* ./../lib/standard//string.nit:100 */
   goto label1;
@@ -479,91 +429,121 @@ val_t string___AbstractString___to_hex(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:104 */
   REGB0 = TAG_Int(16);
   REGB0 = CALL_string___AbstractString___a_to(fra.me.REG[0])(fra.me.REG[0], REGB0);
-  /* ./../lib/standard//string.nit:104 */
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
   return REGB0;
 }
 val_t string___AbstractString___a_to(val_t p0, val_t p1){
-  struct {struct stack_frame_t me;} fra;
+  struct {struct stack_frame_t me; val_t MORE_REG[3];} fra;
   val_t REGB0;
-  val_t REGB1;
-  val_t REGB2;
-  val_t REGB3;
-  val_t REGB4;
-  val_t REGB5;
   val_t tmp;
   fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
   fra.me.file = LOCATE_string;
   fra.me.line = 106;
   fra.me.meth = LOCATE_string___AbstractString___a_to;
   fra.me.has_broke = 0;
-  fra.me.REG_size = 1;
+  fra.me.REG_size = 4;
   fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[1] = NIT_NULL;
+  fra.me.REG[2] = NIT_NULL;
+  fra.me.REG[3] = NIT_NULL;
   fra.me.REG[0] = p0;
   REGB0 = p1;
-  REGB1 = TAG_Int(0);
-  REGB2 = TAG_Bool(false);
-  fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
-  /* ./../lib/standard//string.nit:112 */
-  while(1) {
-    REGB3 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[0])(fra.me.REG[0]);
-    if (UNTAG_Bool(REGB3)) {
-      REGB3 = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
-      REGB3 = CALL_kernel___Char___to_i(REGB3)(REGB3);
-      REGB4 = TAG_Bool(UNTAG_Int(REGB3)>UNTAG_Int(REGB0));
-      /* ./../lib/standard//string.nit:115 */
-      if (UNTAG_Bool(REGB4)) {
-        /* ./../lib/standard//string.nit:116 */
-        if (UNTAG_Bool(REGB2)) {
-          REGB4 = TAG_Int(-UNTAG_Int(REGB1));
-          /* ./../lib/standard//string.nit:117 */
-          goto label1;
-        } else {
-          REGB4 = REGB1;
-          /* ./../lib/standard//string.nit:119 */
-          goto label1;
-        }
-      } else {
-        REGB5 = TAG_Int(0);
-        REGB5 = TAG_Bool(UNTAG_Int(REGB3)<UNTAG_Int(REGB5));
-        /* ./../lib/standard//string.nit:121 */
-        if (UNTAG_Bool(REGB5)) {
-          REGB5 = TAG_Bool(true);
-          REGB2 = REGB5;
-        /* ./../lib/standard//string.nit:122 */
-        } else {
-          REGB5 = TAG_Int(UNTAG_Int(REGB1)*UNTAG_Int(REGB0));
-          REGB3 = TAG_Int(UNTAG_Int(REGB5)+UNTAG_Int(REGB3));
-          REGB1 = REGB3;
-        /* ./../lib/standard//string.nit:124 */
-        }
-      }
-    } else {
-      /* ./../lib/standard//string.nit:112 */
-      goto label2;
-    }
-    CALL_abstract_collection___Iterator___next(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:106 */
+  fra.me.REG[1] = REGB0;
+  /* ./../lib/standard//string.nit:109 */
+  REGB0 = TAG_Int(0);
+  fra.me.REG[2] = REGB0;
+  /* ./../lib/standard//string.nit:110 */
+  REGB0 = TAG_Bool(false);
+  fra.me.REG[3] = REGB0;
+  CALL_abstract_collection___Collection___iterate(fra.me.REG[0])(fra.me.REG[0], (&(fra.me)), ((fun_t)OC_string___AbstractString___a_to_1));
+  switch ((&(fra.me))->has_broke) {
+    case 0: break;
+    case 1: (&(fra.me))->has_broke = 0; goto label3;
   }
-  label2: while(0);
   /* ./../lib/standard//string.nit:127 */
-  if (UNTAG_Bool(REGB2)) {
-    REGB2 = TAG_Int(-UNTAG_Int(REGB1));
-    REGB4 = REGB2;
+  if (UNTAG_Bool(fra.me.REG[3])) {
+    /* ./../lib/standard//kernel.nit:216 */
+    REGB0 = TAG_Int(-UNTAG_Int(fra.me.REG[2]));
     /* ./../lib/standard//string.nit:128 */
-    goto label1;
+    fra.me.REG[0] = REGB0;
+    goto label3;
   } else {
-    REGB4 = REGB1;
     /* ./../lib/standard//string.nit:130 */
-    goto label1;
+    fra.me.REG[0] = fra.me.REG[2];
+    goto label3;
   }
-  label1: while(0);
+  label3: while(0);
   stack_frame_head = fra.me.prev;
-  return REGB4;
+  return fra.me.REG[0];
 }
+  void OC_string___AbstractString___a_to_1(struct stack_frame_t *closctx, val_t p0, struct stack_frame_t *closctx_param, fun_t clos_fun0){
+    struct {struct stack_frame_t me;} fra;
+    val_t REGB0;
+    val_t REGB1;
+    fun_t CREG[1];
+    val_t tmp;
+    /* ./../lib/standard//string.nit:112 */
+    fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+    fra.me.file = LOCATE_string;
+    fra.me.line = 0;
+    fra.me.meth = LOCATE_string___AbstractString___a_to;
+    fra.me.has_broke = 0;
+    fra.me.REG_size = 1;
+    fra.me.REG[0] = NIT_NULL;
+    fra.me.closure_ctx = closctx_param;
+    fra.me.closure_funs = CREG;
+    fra.me.REG[0] = p0;
+    CREG[0] = clos_fun0;
+    REGB0 = fra.me.REG[0];
+    /* ./../lib/standard//string.nit:114 */
+    REGB0 = CALL_kernel___Char___to_i(REGB0)(REGB0);
+    /* ./../lib/standard//kernel.nit:214 */
+    REGB1 = TAG_Bool(UNTAG_Int(REGB0)>UNTAG_Int(closctx->REG[1]));
+    /* ./../lib/standard//string.nit:115 */
+    if (UNTAG_Bool(REGB1)) {
+      /* ./../lib/standard//string.nit:116 */
+      if (UNTAG_Bool(closctx->REG[3])) {
+        /* ./../lib/standard//kernel.nit:216 */
+        REGB1 = TAG_Int(-UNTAG_Int(closctx->REG[2]));
+        /* ./../lib/standard//string.nit:117 */
+        closctx->REG[0] = REGB1;
+        closctx->has_broke = 1;
+        goto label2;
+      } else {
+        /* ./../lib/standard//string.nit:119 */
+        closctx->REG[0] = closctx->REG[2];
+        closctx->has_broke = 1;
+        goto label2;
+      }
+    } else {
+      /* ./../lib/standard//string.nit:121 */
+      REGB1 = TAG_Int(0);
+      /* ./../lib/standard//kernel.nit:212 */
+      REGB1 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB1));
+      /* ./../lib/standard//string.nit:121 */
+      if (UNTAG_Bool(REGB1)) {
+        /* ./../lib/standard//string.nit:122 */
+        REGB1 = TAG_Bool(true);
+        closctx->REG[3] = REGB1;
+      } else {
+        /* ./../lib/standard//kernel.nit:218 */
+        REGB1 = TAG_Int(UNTAG_Int(closctx->REG[2])*UNTAG_Int(closctx->REG[1]));
+        /* ./../lib/standard//kernel.nit:215 */
+        REGB0 = TAG_Int(UNTAG_Int(REGB1)+UNTAG_Int(REGB0));
+        /* ./../lib/standard//string.nit:124 */
+        closctx->REG[2] = REGB0;
+      }
+    }
+    label2: while(0);
+    stack_frame_head = fra.me.prev;
+    return;
+  }
 val_t string___AbstractString___to_upper(val_t p0){
   struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
   val_t REGB0;
@@ -577,37 +557,46 @@ val_t string___AbstractString___to_upper(val_t p0){
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[1] = NIT_NULL;
   fra.me.REG[0] = p0;
-  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB0)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:137 */
   fra.me.REG[1] = NEW_Buffer_string___Buffer___with_capacity(REGB0);
-  fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
-  /* ./../lib/standard//string.nit:138 */
-  while(1) {
-    REGB0 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[0])(fra.me.REG[0]);
-    if (UNTAG_Bool(REGB0)) {
-      REGB0 = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
-      REGB0 = CALL_kernel___Char___to_upper(REGB0)(REGB0);
-      CALL_abstract_collection___SimpleCollection___add(fra.me.REG[1])(fra.me.REG[1], REGB0);
-    } else {
-      goto label1;
-    }
-    CALL_abstract_collection___Iterator___next(fra.me.REG[0])(fra.me.REG[0]);
-  }
-  label1: while(0);
-  fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
+  CALL_abstract_collection___Collection___iterate(fra.me.REG[0])(fra.me.REG[0], (&(fra.me)), ((fun_t)OC_string___AbstractString___to_upper_1));
   /* ./../lib/standard//string.nit:139 */
+  fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
   goto label2;
   label2: while(0);
   stack_frame_head = fra.me.prev;
   return fra.me.REG[1];
 }
+  void OC_string___AbstractString___to_upper_1(struct stack_frame_t *closctx, val_t p0, struct stack_frame_t *closctx_param, fun_t clos_fun0){
+    struct {struct stack_frame_t me;} fra;
+    val_t REGB0;
+    fun_t CREG[1];
+    val_t tmp;
+    /* ./../lib/standard//string.nit:138 */
+    fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+    fra.me.file = LOCATE_string;
+    fra.me.line = 0;
+    fra.me.meth = LOCATE_string___AbstractString___to_upper;
+    fra.me.has_broke = 0;
+    fra.me.REG_size = 1;
+    fra.me.REG[0] = NIT_NULL;
+    fra.me.closure_ctx = closctx_param;
+    fra.me.closure_funs = CREG;
+    fra.me.REG[0] = p0;
+    CREG[0] = clos_fun0;
+    REGB0 = fra.me.REG[0];
+    REGB0 = CALL_kernel___Char___to_upper(REGB0)(REGB0);
+    CALL_abstract_collection___SimpleCollection___add(closctx->REG[1])(closctx->REG[1], REGB0);
+    stack_frame_head = fra.me.prev;
+    return;
+  }
 val_t string___AbstractString___to_lower(val_t p0){
   struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
   val_t REGB0;
@@ -621,101 +610,245 @@ val_t string___AbstractString___to_lower(val_t p0){
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[1] = NIT_NULL;
   fra.me.REG[0] = p0;
-  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB0)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:145 */
   fra.me.REG[1] = NEW_Buffer_string___Buffer___with_capacity(REGB0);
-  fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
-  /* ./../lib/standard//string.nit:146 */
+  CALL_abstract_collection___Collection___iterate(fra.me.REG[0])(fra.me.REG[0], (&(fra.me)), ((fun_t)OC_string___AbstractString___to_lower_1));
+  /* ./../lib/standard//string.nit:147 */
+  fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
+  goto label2;
+  label2: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[1];
+}
+  void OC_string___AbstractString___to_lower_1(struct stack_frame_t *closctx, val_t p0, struct stack_frame_t *closctx_param, fun_t clos_fun0){
+    struct {struct stack_frame_t me;} fra;
+    val_t REGB0;
+    fun_t CREG[1];
+    val_t tmp;
+    /* ./../lib/standard//string.nit:146 */
+    fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+    fra.me.file = LOCATE_string;
+    fra.me.line = 0;
+    fra.me.meth = LOCATE_string___AbstractString___to_lower;
+    fra.me.has_broke = 0;
+    fra.me.REG_size = 1;
+    fra.me.REG[0] = NIT_NULL;
+    fra.me.closure_ctx = closctx_param;
+    fra.me.closure_funs = CREG;
+    fra.me.REG[0] = p0;
+    CREG[0] = clos_fun0;
+    REGB0 = fra.me.REG[0];
+    REGB0 = CALL_kernel___Char___to_lower(REGB0)(REGB0);
+    CALL_abstract_collection___SimpleCollection___add(closctx->REG[1])(closctx->REG[1], REGB0);
+    stack_frame_head = fra.me.prev;
+    return;
+  }
+void string___AbstractString___output(val_t p0){
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+  val_t REGB0;
+  val_t REGB1;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 151;
+  fra.me.meth = LOCATE_string___AbstractString___output;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 2;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[1] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:153 */
+  REGB0 = TAG_Int(0);
+  /* ./../lib/standard//string.nit:154 */
   while(1) {
-    REGB0 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[0])(fra.me.REG[0]);
-    if (UNTAG_Bool(REGB0)) {
-      REGB0 = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
-      REGB0 = CALL_kernel___Char___to_lower(REGB0)(REGB0);
-      CALL_abstract_collection___SimpleCollection___add(fra.me.REG[1])(fra.me.REG[1], REGB0);
+    /* ./../lib/standard//collection//array.nit:23 */
+    REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
+    if (UNTAG_Bool(REGB1)) {
+    } else {
+      nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
+    }
+    REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+    /* ./../lib/standard//kernel.nit:212 */
+    REGB1 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB1));
+    /* ./../lib/standard//string.nit:154 */
+    if (UNTAG_Bool(REGB1)) {
+      /* ./../lib/standard//string.nit:155 */
+      REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
+      if (UNTAG_Bool(REGB1)) {
+      } else {
+        nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 155);
+      }
+      fra.me.REG[1] = ATTR_string___AbstractString____items(fra.me.REG[0]);
+      /* ./../lib/standard//string.nit:585 */
+      REGB1 = TAG_Char(UNBOX_NativeString(fra.me.REG[1])[UNTAG_Int(REGB0)]);
+      /* ./../lib/standard//kernel.nit:349 */
+      printf("%c", (unsigned char)UNTAG_Char(REGB1));;
+      /* ./../lib/standard//string.nit:156 */
+      REGB1 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:215 */
+      REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB1));
+      /* ./../lib/standard//string.nit:156 */
+      REGB0 = REGB1;
     } else {
+      /* ./../lib/standard//string.nit:154 */
       goto label1;
     }
-    CALL_abstract_collection___Iterator___next(fra.me.REG[0])(fra.me.REG[0]);
   }
   label1: while(0);
-  fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
-  /* ./../lib/standard//string.nit:147 */
-  goto label2;
-  label2: while(0);
   stack_frame_head = fra.me.prev;
-  return fra.me.REG[1];
+  return;
 }
-val_t string___String_____eqeq(val_t p0, val_t p1){
+void string___String___with_native(val_t p0, val_t p1, val_t p2, int* init_table){
+  int itpos0 = VAL2OBJ(p0)->vft[INIT_TABLE_POS_String].i;
   struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
   val_t REGB0;
   val_t REGB1;
-  val_t REGB2;
-  val_t REGB3;
-  val_t REGB4;
-  val_t REGB5;
   val_t tmp;
+  if (init_table[itpos0]) return;
   fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
   fra.me.file = LOCATE_string;
-  fra.me.line = 189;
-  fra.me.meth = LOCATE_string___String_____eqeq;
+  fra.me.line = 167;
+  fra.me.meth = LOCATE_string___String___with_native;
   fra.me.has_broke = 0;
   fra.me.REG_size = 2;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[1] = NIT_NULL;
   fra.me.REG[0] = p0;
   fra.me.REG[1] = p1;
-  REGB0 = TAG_Bool((fra.me.REG[1]!=NIT_NULL) && VAL_ISA(fra.me.REG[1], COLOR_String, ID_String)) /*cast String*/;
-  REGB0 = TAG_Bool(!UNTAG_Bool(REGB0));
-  /* ./../lib/standard//string.nit:191 */
-  if (UNTAG_Bool(REGB0)) {
-    REGB0 = TAG_Bool(true);
-  } else {
-    REGB1 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
-    REGB0 = REGB1;
-  }
-  if (UNTAG_Bool(REGB0)) {
+  REGB0 = p2;
+  /* ./../lib/standard//string.nit:170 */
+  REGB1 = TAG_Int(0);
+  /* ./../lib/standard//kernel.nit:213 */
+  REGB1 = TAG_Bool(UNTAG_Int(REGB0)>=UNTAG_Int(REGB1));
+  /* ./../lib/standard//string.nit:170 */
+  if (UNTAG_Bool(REGB1)) {
+  } else {
+    nit_abort("Assert failed", NULL, LOCATE_string, 170);
+  }
+  /* ./../lib/standard//string.nit:171 */
+  ATTR_string___AbstractString____items(fra.me.REG[0]) = fra.me.REG[1];
+  /* ./../lib/standard//string.nit:172 */
+  ATTR_array___AbstractArrayRead____length(fra.me.REG[0]) = REGB0;
+  stack_frame_head = fra.me.prev;
+  init_table[itpos0] = 1;
+  return;
+}
+void string___String___from_cstring(val_t p0, val_t p1, int* init_table){
+  int itpos1 = VAL2OBJ(p0)->vft[INIT_TABLE_POS_String].i;
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+  val_t REGB0;
+  val_t tmp;
+  if (init_table[itpos1]) return;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 175;
+  fra.me.meth = LOCATE_string___String___from_cstring;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 2;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[1] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  fra.me.REG[1] = p1;
+  /* ./../lib/standard//string.nit:178 */
+  REGB0 = CALL_string___NativeString___cstring_length(fra.me.REG[1])(fra.me.REG[1]);
+  /* ./../lib/standard//string.nit:179 */
+  ATTR_string___AbstractString____items(fra.me.REG[0]) = fra.me.REG[1];
+  /* ./../lib/standard//string.nit:180 */
+  ATTR_array___AbstractArrayRead____length(fra.me.REG[0]) = REGB0;
+  stack_frame_head = fra.me.prev;
+  init_table[itpos1] = 1;
+  return;
+}
+val_t string___String___to_cstring(val_t p0){
+  struct {struct stack_frame_t me;} fra;
+  val_t REGB0;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 183;
+  fra.me.meth = LOCATE_string___String___to_cstring;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:186 */
+  REGB0 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 186);
+  }
+  fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[0]);
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+val_t string___String_____eqeq(val_t p0, val_t p1){
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+  val_t REGB0;
+  val_t REGB1;
+  val_t REGB2;
+  val_t REGB3;
+  val_t REGB4;
+  val_t REGB5;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 189;
+  fra.me.meth = LOCATE_string___String_____eqeq;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 2;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[1] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  fra.me.REG[1] = p1;
+  /* ./../lib/standard//string.nit:191 */
+  REGB0 = TAG_Bool((fra.me.REG[1]!=NIT_NULL) && VAL_ISA(fra.me.REG[1], COLOR_String, ID_String)) /*cast String*/;
+  REGB0 = TAG_Bool(!UNTAG_Bool(REGB0));
+  if (UNTAG_Bool(REGB0)) {
+    REGB0 = TAG_Bool(true);
+  } else {
+    REGB1 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
+    REGB0 = REGB1;
+  }
+  if (UNTAG_Bool(REGB0)) {
     REGB0 = TAG_Bool(false);
     goto label1;
   }
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
-  REGB2 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
   /* ./../lib/standard//string.nit:193 */
+  REGB2 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
   if (UNTAG_Bool(REGB2)) {
-    fprintf(stderr, "Reciever is null");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 193);
-    nit_exit(1);
+    nit_abort("Reciever is null", NULL, LOCATE_string, 193);
   }
-  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
   if (UNTAG_Bool(REGB2)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
-  REGB3 = TAG_Bool(IS_EQUAL_OO(REGB2,REGB1));
   /* ./../lib/standard//string.nit:193 */
+  REGB3 = TAG_Bool(IS_EQUAL_OO(REGB2,REGB1));
   if (UNTAG_Bool(REGB3)) {
   } else {
+    /* ./../lib/standard//kernel.nit:207 */
     REGB2 = TAG_Bool((REGB2)==(REGB1));
+    /* ./../lib/standard//string.nit:193 */
     REGB3 = REGB2;
-  /* ./../lib/standard//string.nit:193 */
   }
   REGB3 = TAG_Bool(!UNTAG_Bool(REGB3));
   if (UNTAG_Bool(REGB3)) {
@@ -723,39 +856,39 @@ val_t string___String_____eqeq(val_t p0, val_t p1){
     REGB0 = REGB3;
     goto label1;
   }
+  /* ./../lib/standard//string.nit:194 */
   REGB3 = TAG_Int(0);
-  REGB2 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//string.nit:195 */
+  REGB2 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB2)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 195);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 195);
   }
   fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[0]);
-  REGB2 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[1])!=NIT_NULL);
   /* ./../lib/standard//string.nit:196 */
+  REGB2 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[1])!=NIT_NULL);
   if (UNTAG_Bool(REGB2)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 196);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 196);
   }
   fra.me.REG[1] = ATTR_string___AbstractString____items(fra.me.REG[1]);
   /* ./../lib/standard//string.nit:197 */
   while(1) {
+    /* ./../lib/standard//kernel.nit:212 */
     REGB2 = TAG_Bool(UNTAG_Int(REGB3)<UNTAG_Int(REGB1));
     /* ./../lib/standard//string.nit:197 */
     if (UNTAG_Bool(REGB2)) {
+      /* ./../lib/standard//string.nit:585 */
       REGB2 = TAG_Char(UNBOX_NativeString(fra.me.REG[0])[UNTAG_Int(REGB3)]);
       REGB4 = TAG_Char(UNBOX_NativeString(fra.me.REG[1])[UNTAG_Int(REGB3)]);
-      REGB5 = TAG_Bool(IS_EQUAL_OO(REGB2,REGB4));
       /* ./../lib/standard//string.nit:198 */
+      REGB5 = TAG_Bool(IS_EQUAL_OO(REGB2,REGB4));
       if (UNTAG_Bool(REGB5)) {
       } else {
+        /* ./../lib/standard//kernel.nit:347 */
         REGB4 = TAG_Bool((REGB2)==(REGB4));
+        /* ./../lib/standard//string.nit:198 */
         REGB5 = REGB4;
-      /* ./../lib/standard//string.nit:198 */
       }
       REGB5 = TAG_Bool(!UNTAG_Bool(REGB5));
       if (UNTAG_Bool(REGB5)) {
@@ -763,19 +896,21 @@ val_t string___String_____eqeq(val_t p0, val_t p1){
         REGB0 = REGB5;
         goto label1;
       }
+      /* ./../lib/standard//string.nit:199 */
       REGB5 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:215 */
       REGB5 = TAG_Int(UNTAG_Int(REGB3)+UNTAG_Int(REGB5));
+      /* ./../lib/standard//string.nit:199 */
       REGB3 = REGB5;
-    /* ./../lib/standard//string.nit:199 */
     } else {
       /* ./../lib/standard//string.nit:197 */
       goto label2;
     }
   }
   label2: while(0);
+  /* ./../lib/standard//string.nit:201 */
   REGB3 = TAG_Bool(true);
   REGB0 = REGB3;
-  /* ./../lib/standard//string.nit:201 */
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
@@ -800,102 +935,229 @@ val_t string___String_____l(val_t p0, val_t p1){
   fra.me.REG[1] = NIT_NULL;
   fra.me.REG[0] = p0;
   fra.me.REG[1] = p1;
+  /* ./../lib/standard//string.nit:206 */
   REGB0 = TAG_Int(0);
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
   REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
-  /* ./../lib/standard//collection//array.nit:23 */
   if (UNTAG_Bool(REGB2)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
-  REGB3 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//string.nit:209 */
+  REGB3 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB3)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 209);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 209);
   }
   fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[0]);
-  REGB3 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[1])!=NIT_NULL);
   /* ./../lib/standard//string.nit:210 */
+  REGB3 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[1])!=NIT_NULL);
   if (UNTAG_Bool(REGB3)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 210);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 210);
   }
   fra.me.REG[1] = ATTR_string___AbstractString____items(fra.me.REG[1]);
   /* ./../lib/standard//string.nit:211 */
   while(1) {
+    /* ./../lib/standard//kernel.nit:212 */
     REGB3 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB1));
     /* ./../lib/standard//string.nit:211 */
     if (UNTAG_Bool(REGB3)) {
+      /* ./../lib/standard//kernel.nit:212 */
       REGB3 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB2));
-    /* ./../lib/standard//string.nit:211 */
     } else {
+      /* ./../lib/standard//string.nit:211 */
       REGB4 = TAG_Bool(false);
       REGB3 = REGB4;
     }
     if (UNTAG_Bool(REGB3)) {
+      /* ./../lib/standard//string.nit:585 */
       REGB3 = TAG_Char(UNBOX_NativeString(fra.me.REG[0])[UNTAG_Int(REGB0)]);
+      /* ./../lib/standard//kernel.nit:382 */
       REGB3 = TAG_Int((unsigned char)UNTAG_Char(REGB3));
+      /* ./../lib/standard//string.nit:585 */
       REGB4 = TAG_Char(UNBOX_NativeString(fra.me.REG[1])[UNTAG_Int(REGB0)]);
+      /* ./../lib/standard//kernel.nit:382 */
       REGB4 = TAG_Int((unsigned char)UNTAG_Char(REGB4));
+      /* ./../lib/standard//kernel.nit:212 */
       REGB5 = TAG_Bool(UNTAG_Int(REGB3)<UNTAG_Int(REGB4));
       /* ./../lib/standard//string.nit:214 */
       if (UNTAG_Bool(REGB5)) {
-        REGB5 = TAG_Bool(true);
         /* ./../lib/standard//string.nit:215 */
+        REGB5 = TAG_Bool(true);
         goto label1;
       } else {
+        /* ./../lib/standard//kernel.nit:212 */
         REGB3 = TAG_Bool(UNTAG_Int(REGB4)<UNTAG_Int(REGB3));
         /* ./../lib/standard//string.nit:216 */
         if (UNTAG_Bool(REGB3)) {
+          /* ./../lib/standard//string.nit:217 */
           REGB3 = TAG_Bool(false);
           REGB5 = REGB3;
-          /* ./../lib/standard//string.nit:217 */
           goto label1;
         }
       }
+      /* ./../lib/standard//string.nit:219 */
       REGB3 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:215 */
       REGB3 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB3));
+      /* ./../lib/standard//string.nit:219 */
       REGB0 = REGB3;
-    /* ./../lib/standard//string.nit:219 */
     } else {
       /* ./../lib/standard//string.nit:211 */
       goto label2;
     }
   }
   label2: while(0);
+  /* ./../lib/standard//kernel.nit:212 */
   REGB2 = TAG_Bool(UNTAG_Int(REGB1)<UNTAG_Int(REGB2));
   /* ./../lib/standard//string.nit:221 */
   if (UNTAG_Bool(REGB2)) {
+    /* ./../lib/standard//string.nit:222 */
     REGB2 = TAG_Bool(true);
     REGB5 = REGB2;
-    /* ./../lib/standard//string.nit:222 */
     goto label1;
   } else {
+    /* ./../lib/standard//string.nit:224 */
     REGB2 = TAG_Bool(false);
     REGB5 = REGB2;
-    /* ./../lib/standard//string.nit:224 */
     goto label1;
   }
   label1: while(0);
   stack_frame_head = fra.me.prev;
   return REGB5;
 }
+val_t string___String_____plus(val_t p0, val_t p1){
+  struct {struct stack_frame_t me; val_t MORE_REG[2];} fra;
+  val_t REGB0;
+  val_t REGB1;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 228;
+  fra.me.meth = LOCATE_string___String_____plus;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 3;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[1] = NIT_NULL;
+  fra.me.REG[2] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  fra.me.REG[1] = p1;
+  /* ./../lib/standard//collection//array.nit:23 */
+  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
+  }
+  REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
+  if (UNTAG_Bool(REGB1)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
+  }
+  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
+  /* ./../lib/standard//kernel.nit:215 */
+  REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB1));
+  /* ./../lib/standard//string.nit:231 */
+  fra.me.REG[2] = NEW_Buffer_string___Buffer___with_capacity(REGB1);
+  /* ./../lib/standard//string.nit:232 */
+  CALL_abstract_collection___Sequence___append(fra.me.REG[2])(fra.me.REG[2], fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:233 */
+  CALL_abstract_collection___Sequence___append(fra.me.REG[2])(fra.me.REG[2], fra.me.REG[1]);
+  /* ./../lib/standard//string.nit:234 */
+  fra.me.REG[2] = CALL_string___Object___to_s(fra.me.REG[2])(fra.me.REG[2]);
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[2];
+}
+val_t string___String_____star(val_t p0, val_t p1){
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+  val_t REGB0;
+  val_t REGB1;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 237;
+  fra.me.meth = LOCATE_string___String_____star;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 2;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[1] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  REGB0 = p1;
+  /* ./../lib/standard//string.nit:240 */
+  REGB1 = TAG_Int(0);
+  /* ./../lib/standard//kernel.nit:213 */
+  REGB1 = TAG_Bool(UNTAG_Int(REGB0)>=UNTAG_Int(REGB1));
+  /* ./../lib/standard//string.nit:240 */
+  if (UNTAG_Bool(REGB1)) {
+  } else {
+    nit_abort("Assert failed", NULL, LOCATE_string, 240);
+  }
+  /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB1)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
+  }
+  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//kernel.nit:218 */
+  REGB1 = TAG_Int(UNTAG_Int(REGB1)*UNTAG_Int(REGB0));
+  /* ./../lib/standard//string.nit:241 */
+  fra.me.REG[1] = NEW_Buffer_string___Buffer___with_capacity(REGB1);
+  /* ./../lib/standard//string.nit:242 */
+  while(1) {
+    REGB1 = TAG_Int(0);
+    /* ./../lib/standard//kernel.nit:214 */
+    REGB1 = TAG_Bool(UNTAG_Int(REGB0)>UNTAG_Int(REGB1));
+    /* ./../lib/standard//string.nit:242 */
+    if (UNTAG_Bool(REGB1)) {
+      /* ./../lib/standard//string.nit:243 */
+      CALL_abstract_collection___Sequence___append(fra.me.REG[1])(fra.me.REG[1], fra.me.REG[0]);
+      /* ./../lib/standard//string.nit:244 */
+      REGB1 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:217 */
+      REGB1 = TAG_Int(UNTAG_Int(REGB0)-UNTAG_Int(REGB1));
+      /* ./../lib/standard//string.nit:244 */
+      REGB0 = REGB1;
+    } else {
+      /* ./../lib/standard//string.nit:242 */
+      goto label1;
+    }
+  }
+  label1: while(0);
+  /* ./../lib/standard//string.nit:246 */
+  fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
+  goto label2;
+  label2: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[1];
+}
+val_t string___String___to_s(val_t p0){
+  struct {struct stack_frame_t me;} fra;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 249;
+  fra.me.meth = LOCATE_string___String___to_s;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:249 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
 val_t string___String___hash(val_t p0){
   struct {struct stack_frame_t me;} fra;
   val_t REGB0;
@@ -911,44 +1173,52 @@ val_t string___String___hash(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:254 */
   REGB0 = TAG_Int(5381);
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//string.nit:255 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 255);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_string, 255);
   }
   REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
   REGB2 = TAG_Int(1);
+  /* ./../lib/standard//kernel.nit:217 */
   REGB2 = TAG_Int(UNTAG_Int(REGB1)-UNTAG_Int(REGB2));
-  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//string.nit:256 */
+  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 256);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 256);
   }
   fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[0]);
   /* ./../lib/standard//string.nit:257 */
   while(1) {
     REGB1 = TAG_Int(0);
+    /* ./../lib/standard//kernel.nit:213 */
     REGB1 = TAG_Bool(UNTAG_Int(REGB2)>=UNTAG_Int(REGB1));
     /* ./../lib/standard//string.nit:257 */
     if (UNTAG_Bool(REGB1)) {
+      /* ./../lib/standard//string.nit:258 */
       REGB1 = TAG_Int(32);
+      /* ./../lib/standard//kernel.nit:218 */
       REGB1 = TAG_Int(UNTAG_Int(REGB0)*UNTAG_Int(REGB1));
+      /* ./../lib/standard//kernel.nit:215 */
       REGB1 = TAG_Int(UNTAG_Int(REGB1)+UNTAG_Int(REGB0));
+      /* ./../lib/standard//string.nit:585 */
       REGB3 = TAG_Char(UNBOX_NativeString(fra.me.REG[0])[UNTAG_Int(REGB2)]);
+      /* ./../lib/standard//kernel.nit:382 */
       REGB3 = TAG_Int((unsigned char)UNTAG_Char(REGB3));
+      /* ./../lib/standard//kernel.nit:215 */
       REGB3 = TAG_Int(UNTAG_Int(REGB1)+UNTAG_Int(REGB3));
+      /* ./../lib/standard//string.nit:258 */
       REGB0 = REGB3;
+      /* ./../lib/standard//string.nit:259 */
       REGB3 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:217 */
       REGB3 = TAG_Int(UNTAG_Int(REGB2)-UNTAG_Int(REGB3));
+      /* ./../lib/standard//string.nit:259 */
       REGB2 = REGB3;
-    /* ./../lib/standard//string.nit:259 */
     } else {
       /* ./../lib/standard//string.nit:257 */
       goto label1;
@@ -961,543 +1231,38 @@ val_t string___String___hash(val_t p0){
   stack_frame_head = fra.me.prev;
   return REGB0;
 }
-val_t string___String___to_s(val_t p0){
+void string___Buffer_____braeq(val_t p0, val_t p1, val_t p2){
   struct {struct stack_frame_t me;} fra;
+  val_t REGB0;
+  val_t REGB1;
+  val_t REGB2;
+  val_t REGB3;
   val_t tmp;
   fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
   fra.me.file = LOCATE_string;
-  fra.me.line = 249;
-  fra.me.meth = LOCATE_string___String___to_s;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 1;
-  fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[0] = p0;
-  /* ./../lib/standard//string.nit:249 */
-  goto label1;
-  label1: while(0);
-  stack_frame_head = fra.me.prev;
-  return fra.me.REG[0];
-}
-void string___String___with_native(val_t p0, val_t p1, val_t p2, int* init_table){
-  int itpos0 = VAL2OBJ(p0)->vft[INIT_TABLE_POS_String].i;
-  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
-  val_t REGB0;
-  val_t REGB1;
-  val_t tmp;
-  if (init_table[itpos0]) return;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 167;
-  fra.me.meth = LOCATE_string___String___with_native;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 2;
-  fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[1] = NIT_NULL;
-  fra.me.REG[0] = p0;
-  fra.me.REG[1] = p1;
-  REGB0 = p2;
-  REGB1 = TAG_Int(0);
-  REGB1 = TAG_Bool(UNTAG_Int(REGB0)>=UNTAG_Int(REGB1));
-  /* ./../lib/standard//string.nit:170 */
-  if (UNTAG_Bool(REGB1)) {
-  } else {
-    fprintf(stderr, "Assert failed");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 170);
-    nit_exit(1);
-  }
-  /* ./../lib/standard//string.nit:171 */
-  ATTR_string___AbstractString____items(fra.me.REG[0]) = fra.me.REG[1];
-  /* ./../lib/standard//string.nit:172 */
-  ATTR_array___AbstractArrayRead____length(fra.me.REG[0]) = REGB0;
-  stack_frame_head = fra.me.prev;
-  init_table[itpos0] = 1;
-  return;
-}
-void string___String___from_cstring(val_t p0, val_t p1, int* init_table){
-  int itpos1 = VAL2OBJ(p0)->vft[INIT_TABLE_POS_String].i;
-  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
-  val_t REGB0;
-  val_t tmp;
-  if (init_table[itpos1]) return;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 175;
-  fra.me.meth = LOCATE_string___String___from_cstring;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 2;
-  fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[1] = NIT_NULL;
-  fra.me.REG[0] = p0;
-  fra.me.REG[1] = p1;
-  REGB0 = CALL_string___NativeString___cstring_length(fra.me.REG[1])(fra.me.REG[1]);
-  /* ./../lib/standard//string.nit:179 */
-  ATTR_string___AbstractString____items(fra.me.REG[0]) = fra.me.REG[1];
-  /* ./../lib/standard//string.nit:180 */
-  ATTR_array___AbstractArrayRead____length(fra.me.REG[0]) = REGB0;
-  stack_frame_head = fra.me.prev;
-  init_table[itpos1] = 1;
-  return;
-}
-val_t string___String___to_cstring(val_t p0){
-  struct {struct stack_frame_t me;} fra;
-  val_t REGB0;
-  val_t tmp;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 183;
-  fra.me.meth = LOCATE_string___String___to_cstring;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 1;
-  fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[0] = p0;
-  REGB0 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//string.nit:186 */
-  if (UNTAG_Bool(REGB0)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 186);
-    nit_exit(1);
-  }
-  fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[0]);
-  goto label1;
-  label1: while(0);
-  stack_frame_head = fra.me.prev;
-  return fra.me.REG[0];
-}
-val_t string___String_____plus(val_t p0, val_t p1){
-  struct {struct stack_frame_t me; val_t MORE_REG[2];} fra;
-  val_t REGB0;
-  val_t REGB1;
-  val_t tmp;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 228;
-  fra.me.meth = LOCATE_string___String_____plus;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 3;
-  fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[1] = NIT_NULL;
-  fra.me.REG[2] = NIT_NULL;
-  fra.me.REG[0] = p0;
-  fra.me.REG[1] = p1;
-  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//collection//array.nit:23 */
-  if (UNTAG_Bool(REGB0)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
-  }
-  REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
-  if (UNTAG_Bool(REGB1)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
-  }
-  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
-  REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB1));
-  fra.me.REG[2] = NEW_Buffer_string___Buffer___with_capacity(REGB1);
-  /* ./../lib/standard//string.nit:232 */
-  CALL_abstract_collection___Sequence___append(fra.me.REG[2])(fra.me.REG[2], fra.me.REG[0]);
-  /* ./../lib/standard//string.nit:233 */
-  CALL_abstract_collection___Sequence___append(fra.me.REG[2])(fra.me.REG[2], fra.me.REG[1]);
-  fra.me.REG[2] = CALL_string___Object___to_s(fra.me.REG[2])(fra.me.REG[2]);
-  /* ./../lib/standard//string.nit:234 */
-  goto label1;
-  label1: while(0);
-  stack_frame_head = fra.me.prev;
-  return fra.me.REG[2];
-}
-val_t string___String_____star(val_t p0, val_t p1){
-  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
-  val_t REGB0;
-  val_t REGB1;
-  val_t tmp;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 237;
-  fra.me.meth = LOCATE_string___String_____star;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 2;
-  fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[1] = NIT_NULL;
-  fra.me.REG[0] = p0;
-  REGB0 = p1;
-  REGB1 = TAG_Int(0);
-  REGB1 = TAG_Bool(UNTAG_Int(REGB0)>=UNTAG_Int(REGB1));
-  /* ./../lib/standard//string.nit:240 */
-  if (UNTAG_Bool(REGB1)) {
-  } else {
-    fprintf(stderr, "Assert failed");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 240);
-    nit_exit(1);
-  }
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//collection//array.nit:23 */
-  if (UNTAG_Bool(REGB1)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
-  }
-  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
-  REGB1 = TAG_Int(UNTAG_Int(REGB1)*UNTAG_Int(REGB0));
-  fra.me.REG[1] = NEW_Buffer_string___Buffer___with_capacity(REGB1);
-  /* ./../lib/standard//string.nit:242 */
-  while(1) {
-    REGB1 = TAG_Int(0);
-    REGB1 = TAG_Bool(UNTAG_Int(REGB0)>UNTAG_Int(REGB1));
-    /* ./../lib/standard//string.nit:242 */
-    if (UNTAG_Bool(REGB1)) {
-      /* ./../lib/standard//string.nit:243 */
-      CALL_abstract_collection___Sequence___append(fra.me.REG[1])(fra.me.REG[1], fra.me.REG[0]);
-      REGB1 = TAG_Int(1);
-      REGB1 = TAG_Int(UNTAG_Int(REGB0)-UNTAG_Int(REGB1));
-      REGB0 = REGB1;
-    /* ./../lib/standard//string.nit:244 */
-    } else {
-      /* ./../lib/standard//string.nit:242 */
-      goto label1;
-    }
-  }
-  label1: while(0);
-  fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
-  /* ./../lib/standard//string.nit:246 */
-  goto label2;
-  label2: while(0);
-  stack_frame_head = fra.me.prev;
-  return fra.me.REG[1];
-}
-val_t string___Buffer_____eqeq(val_t p0, val_t p1){
-  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
-  val_t REGB0;
-  val_t REGB1;
-  val_t REGB2;
-  val_t REGB3;
-  val_t REGB4;
-  val_t REGB5;
-  val_t tmp;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 373;
-  fra.me.meth = LOCATE_string___Buffer_____eqeq;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 2;
-  fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[1] = NIT_NULL;
-  fra.me.REG[0] = p0;
-  fra.me.REG[1] = p1;
-  REGB0 = TAG_Bool((fra.me.REG[1]!=NIT_NULL) && VAL_ISA(fra.me.REG[1], COLOR_Buffer, ID_Buffer)) /*cast Buffer*/;
-  REGB0 = TAG_Bool(!UNTAG_Bool(REGB0));
-  /* ./../lib/standard//string.nit:375 */
-  if (UNTAG_Bool(REGB0)) {
-    REGB0 = TAG_Bool(true);
-  } else {
-    REGB1 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
-    REGB0 = REGB1;
-  }
-  if (UNTAG_Bool(REGB0)) {
-    REGB0 = TAG_Bool(false);
-    goto label1;
-  }
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//collection//array.nit:23 */
-  if (UNTAG_Bool(REGB1)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
-  }
-  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
-  REGB2 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
-  /* ./../lib/standard//string.nit:377 */
-  if (UNTAG_Bool(REGB2)) {
-    fprintf(stderr, "Reciever is null");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 377);
-    nit_exit(1);
-  }
-  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
-  /* ./../lib/standard//collection//array.nit:23 */
-  if (UNTAG_Bool(REGB2)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
-  }
-  REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
-  REGB3 = TAG_Bool(IS_EQUAL_OO(REGB2,REGB1));
-  /* ./../lib/standard//string.nit:377 */
-  if (UNTAG_Bool(REGB3)) {
-  } else {
-    REGB2 = TAG_Bool((REGB2)==(REGB1));
-    REGB3 = REGB2;
-  /* ./../lib/standard//string.nit:377 */
-  }
-  REGB3 = TAG_Bool(!UNTAG_Bool(REGB3));
-  if (UNTAG_Bool(REGB3)) {
-    REGB3 = TAG_Bool(false);
-    REGB0 = REGB3;
-    goto label1;
-  }
-  REGB3 = TAG_Int(0);
-  REGB2 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//string.nit:379 */
-  if (UNTAG_Bool(REGB2)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 379);
-    nit_exit(1);
-  }
-  fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[0]);
-  REGB2 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[1])!=NIT_NULL);
-  /* ./../lib/standard//string.nit:380 */
-  if (UNTAG_Bool(REGB2)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 380);
-    nit_exit(1);
-  }
-  fra.me.REG[1] = ATTR_string___AbstractString____items(fra.me.REG[1]);
-  /* ./../lib/standard//string.nit:381 */
-  while(1) {
-    REGB2 = TAG_Bool(UNTAG_Int(REGB3)<UNTAG_Int(REGB1));
-    /* ./../lib/standard//string.nit:381 */
-    if (UNTAG_Bool(REGB2)) {
-      REGB2 = TAG_Char(UNBOX_NativeString(fra.me.REG[0])[UNTAG_Int(REGB3)]);
-      REGB4 = TAG_Char(UNBOX_NativeString(fra.me.REG[1])[UNTAG_Int(REGB3)]);
-      REGB5 = TAG_Bool(IS_EQUAL_OO(REGB2,REGB4));
-      /* ./../lib/standard//string.nit:382 */
-      if (UNTAG_Bool(REGB5)) {
-      } else {
-        REGB4 = TAG_Bool((REGB2)==(REGB4));
-        REGB5 = REGB4;
-      /* ./../lib/standard//string.nit:382 */
-      }
-      REGB5 = TAG_Bool(!UNTAG_Bool(REGB5));
-      if (UNTAG_Bool(REGB5)) {
-        REGB5 = TAG_Bool(false);
-        REGB0 = REGB5;
-        goto label1;
-      }
-      REGB5 = TAG_Int(1);
-      REGB5 = TAG_Int(UNTAG_Int(REGB3)+UNTAG_Int(REGB5));
-      REGB3 = REGB5;
-    /* ./../lib/standard//string.nit:383 */
-    } else {
-      /* ./../lib/standard//string.nit:381 */
-      goto label2;
-    }
-  }
-  label2: while(0);
-  REGB3 = TAG_Bool(true);
-  REGB0 = REGB3;
-  /* ./../lib/standard//string.nit:385 */
-  goto label1;
-  label1: while(0);
-  stack_frame_head = fra.me.prev;
-  return REGB0;
-}
-val_t string___Buffer___to_s(val_t p0){
-  struct {struct stack_frame_t me; val_t MORE_REG[2];} fra;
-  val_t REGB0;
-  val_t REGB1;
-  val_t REGB2;
-  val_t tmp;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 315;
-  fra.me.meth = LOCATE_string___Buffer___to_s;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 3;
-  fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[1] = NIT_NULL;
-  fra.me.REG[2] = NIT_NULL;
-  fra.me.REG[0] = p0;
-  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//collection//array.nit:23 */
-  if (UNTAG_Bool(REGB0)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
-  }
-  REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
-  REGB1 = TAG_Int(1);
-  REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB1));
-  fra.me.REG[1] = BOX_NativeString((char*)raw_alloc((UNTAG_Int(REGB1) * sizeof(char))));
-  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//string.nit:319 */
-  if (UNTAG_Bool(REGB1)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 319);
-    nit_exit(1);
-  }
-  fra.me.REG[2] = ATTR_string___AbstractString____items(fra.me.REG[0]);
-  REGB1 = TAG_Int(0);
-  REGB2 = TAG_Int(0);
-  /* ./../lib/standard//string.nit:587 */
-  (void)memcpy(UNBOX_NativeString(fra.me.REG[1])+UNTAG_Int(REGB2), UNBOX_NativeString(fra.me.REG[2])+UNTAG_Int(REGB1), UNTAG_Int(REGB0));;
-  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//collection//array.nit:23 */
-  if (UNTAG_Bool(REGB0)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
-  }
-  REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
-  REGB1 = TAG_Char('\0');
-  /* ./../lib/standard//string.nit:586 */
-  UNBOX_NativeString(fra.me.REG[1])[UNTAG_Int(REGB0)]=UNTAG_Char(REGB1);;
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//collection//array.nit:23 */
-  if (UNTAG_Bool(REGB1)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
-  }
-  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
-  fra.me.REG[1] = NEW_String_string___String___with_native(fra.me.REG[1], REGB1);
-  /* ./../lib/standard//string.nit:324 */
-  goto label1;
-  label1: while(0);
-  stack_frame_head = fra.me.prev;
-  return fra.me.REG[1];
-}
-val_t string___Buffer_____l(val_t p0, val_t p1){
-  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
-  val_t REGB0;
-  val_t REGB1;
-  val_t REGB2;
-  val_t REGB3;
-  val_t REGB4;
-  val_t REGB5;
-  val_t tmp;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 327;
-  fra.me.meth = LOCATE_string___Buffer_____l;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 2;
-  fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[1] = NIT_NULL;
-  fra.me.REG[0] = p0;
-  fra.me.REG[1] = p1;
-  REGB0 = TAG_Int(0);
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//collection//array.nit:23 */
-  if (UNTAG_Bool(REGB1)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
-  }
-  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
-  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
-  /* ./../lib/standard//collection//array.nit:23 */
-  if (UNTAG_Bool(REGB2)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
-  }
-  REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
-  /* ./../lib/standard//string.nit:332 */
-  while(1) {
-    REGB3 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB1));
-    /* ./../lib/standard//string.nit:332 */
-    if (UNTAG_Bool(REGB3)) {
-      REGB3 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB2));
-    /* ./../lib/standard//string.nit:332 */
-    } else {
-      REGB4 = TAG_Bool(false);
-      REGB3 = REGB4;
-    }
-    if (UNTAG_Bool(REGB3)) {
-      REGB3 = CALL_abstract_collection___MapRead_____bra(fra.me.REG[0])(fra.me.REG[0], REGB0);
-      REGB3 = TAG_Int((unsigned char)UNTAG_Char(REGB3));
-      REGB4 = CALL_abstract_collection___MapRead_____bra(fra.me.REG[1])(fra.me.REG[1], REGB0);
-      REGB4 = TAG_Int((unsigned char)UNTAG_Char(REGB4));
-      REGB5 = TAG_Bool(UNTAG_Int(REGB3)<UNTAG_Int(REGB4));
-      /* ./../lib/standard//string.nit:335 */
-      if (UNTAG_Bool(REGB5)) {
-        REGB5 = TAG_Bool(true);
-        /* ./../lib/standard//string.nit:336 */
-        goto label1;
-      } else {
-        REGB3 = TAG_Bool(UNTAG_Int(REGB4)<UNTAG_Int(REGB3));
-        /* ./../lib/standard//string.nit:337 */
-        if (UNTAG_Bool(REGB3)) {
-          REGB3 = TAG_Bool(false);
-          REGB5 = REGB3;
-          /* ./../lib/standard//string.nit:338 */
-          goto label1;
-        }
-      }
-      REGB3 = TAG_Int(1);
-      REGB3 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB3));
-      REGB0 = REGB3;
-    /* ./../lib/standard//string.nit:340 */
-    } else {
-      /* ./../lib/standard//string.nit:332 */
-      goto label2;
-    }
-  }
-  label2: while(0);
-  REGB2 = TAG_Bool(UNTAG_Int(REGB1)<UNTAG_Int(REGB2));
-  /* ./../lib/standard//string.nit:342 */
-  if (UNTAG_Bool(REGB2)) {
-    REGB2 = TAG_Bool(true);
-    REGB5 = REGB2;
-    /* ./../lib/standard//string.nit:343 */
-    goto label1;
-  } else {
-    REGB2 = TAG_Bool(false);
-    REGB5 = REGB2;
-    /* ./../lib/standard//string.nit:345 */
-    goto label1;
-  }
-  label1: while(0);
-  stack_frame_head = fra.me.prev;
-  return REGB5;
-}
-void string___Buffer_____braeq(val_t p0, val_t p1, val_t p2){
-  struct {struct stack_frame_t me;} fra;
-  val_t REGB0;
-  val_t REGB1;
-  val_t REGB2;
-  val_t REGB3;
-  val_t tmp;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 275;
-  fra.me.meth = LOCATE_string___Buffer_____braeq;
+  fra.me.line = 275;
+  fra.me.meth = LOCATE_string___Buffer_____braeq;
   fra.me.has_broke = 0;
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
   REGB0 = p1;
   REGB1 = p2;
-  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB2)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
-  REGB3 = TAG_Bool(IS_EQUAL_OO(REGB0,REGB2));
   /* ./../lib/standard//string.nit:277 */
+  REGB3 = TAG_Bool(IS_EQUAL_OO(REGB0,REGB2));
   if (UNTAG_Bool(REGB3)) {
   } else {
+    /* ./../lib/standard//kernel.nit:207 */
     REGB2 = TAG_Bool((REGB0)==(REGB2));
+    /* ./../lib/standard//string.nit:277 */
     REGB3 = REGB2;
-  /* ./../lib/standard//string.nit:277 */
   }
   if (UNTAG_Bool(REGB3)) {
     /* ./../lib/standard//string.nit:278 */
@@ -1505,38 +1270,35 @@ void string___Buffer_____braeq(val_t p0, val_t p1, val_t p2){
     /* ./../lib/standard//string.nit:279 */
     goto label1;
   }
+  /* ./../lib/standard//string.nit:281 */
   REGB3 = TAG_Int(0);
+  /* ./../lib/standard//kernel.nit:213 */
   REGB3 = TAG_Bool(UNTAG_Int(REGB0)>=UNTAG_Int(REGB3));
   /* ./../lib/standard//string.nit:281 */
   if (UNTAG_Bool(REGB3)) {
-    REGB3 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
     /* ./../lib/standard//collection//array.nit:23 */
+    REGB3 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
     if (UNTAG_Bool(REGB3)) {
     } else {
-      fprintf(stderr, "Uninitialized attribute %s", "_length");
-      fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-      nit_exit(1);
+      nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
     }
     REGB3 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+    /* ./../lib/standard//kernel.nit:212 */
     REGB3 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB3));
-  /* ./../lib/standard//string.nit:281 */
   } else {
+    /* ./../lib/standard//string.nit:281 */
     REGB2 = TAG_Bool(false);
     REGB3 = REGB2;
   }
   if (UNTAG_Bool(REGB3)) {
   } else {
-    fprintf(stderr, "Assert failed");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 281);
-    nit_exit(1);
+    nit_abort("Assert failed", NULL, LOCATE_string, 281);
   }
-  REGB3 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//string.nit:282 */
+  REGB3 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB3)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 282);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 282);
   }
   fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[0]);
   /* ./../lib/standard//string.nit:586 */
@@ -1561,69 +1323,148 @@ void string___Buffer___add(val_t p0, val_t p1){
   fra.me.REG[1] = NIT_NULL;
   fra.me.REG[0] = p0;
   REGB0 = p1;
-  REGB1 = TAG_Bool(ATTR_string___Buffer____capacity(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//string.nit:287 */
+  REGB1 = TAG_Bool(ATTR_string___Buffer____capacity(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_capacity");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 287);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_capacity", LOCATE_string, 287);
   }
   REGB1 = ATTR_string___Buffer____capacity(fra.me.REG[0]);
-  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB2)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//kernel.nit:211 */
   REGB2 = TAG_Bool(UNTAG_Int(REGB1)<=UNTAG_Int(REGB2));
   /* ./../lib/standard//string.nit:287 */
   if (UNTAG_Bool(REGB2)) {
-    REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
     /* ./../lib/standard//collection//array.nit:23 */
+    REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
     if (UNTAG_Bool(REGB2)) {
     } else {
-      fprintf(stderr, "Uninitialized attribute %s", "_length");
-      fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-      nit_exit(1);
+      nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
     }
     REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+    /* ./../lib/standard//string.nit:287 */
     REGB1 = TAG_Int(5);
+    /* ./../lib/standard//kernel.nit:215 */
     REGB1 = TAG_Int(UNTAG_Int(REGB2)+UNTAG_Int(REGB1));
     /* ./../lib/standard//string.nit:287 */
     CALL_array___AbstractArray___enlarge(fra.me.REG[0])(fra.me.REG[0], REGB1);
   }
-  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//string.nit:288 */
+  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 288);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 288);
   }
   fra.me.REG[1] = ATTR_string___AbstractString____items(fra.me.REG[0]);
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
   /* ./../lib/standard//string.nit:586 */
   UNBOX_NativeString(fra.me.REG[1])[UNTAG_Int(REGB1)]=UNTAG_Char(REGB0);;
+  /* ./../lib/standard//string.nit:289 */
   REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
   REGB1 = TAG_Int(1);
+  /* ./../lib/standard//kernel.nit:215 */
   REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB1));
   /* ./../lib/standard//string.nit:289 */
   ATTR_array___AbstractArrayRead____length(fra.me.REG[0]) = REGB1;
   stack_frame_head = fra.me.prev;
   return;
 }
+void string___Buffer___enlarge(val_t p0, val_t p1){
+  struct {struct stack_frame_t me; val_t MORE_REG[2];} fra;
+  val_t REGB0;
+  val_t REGB1;
+  val_t REGB2;
+  val_t REGB3;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 292;
+  fra.me.meth = LOCATE_string___Buffer___enlarge;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 3;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[1] = NIT_NULL;
+  fra.me.REG[2] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  REGB0 = p1;
+  /* ./../lib/standard//string.nit:294 */
+  REGB1 = TAG_Bool(ATTR_string___Buffer____capacity(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB1)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_capacity", LOCATE_string, 294);
+  }
+  REGB1 = ATTR_string___Buffer____capacity(fra.me.REG[0]);
+  /* ./../lib/standard//kernel.nit:211 */
+  REGB2 = TAG_Bool(UNTAG_Int(REGB0)<=UNTAG_Int(REGB1));
+  /* ./../lib/standard//string.nit:295 */
+  if (UNTAG_Bool(REGB2)) {
+    goto label1;
+  }
+  /* ./../lib/standard//string.nit:296 */
+  while(1) {
+    /* ./../lib/standard//kernel.nit:211 */
+    REGB2 = TAG_Bool(UNTAG_Int(REGB1)<=UNTAG_Int(REGB0));
+    /* ./../lib/standard//string.nit:296 */
+    if (UNTAG_Bool(REGB2)) {
+      REGB2 = TAG_Int(2);
+      /* ./../lib/standard//kernel.nit:218 */
+      REGB2 = TAG_Int(UNTAG_Int(REGB1)*UNTAG_Int(REGB2));
+      /* ./../lib/standard//string.nit:296 */
+      REGB3 = TAG_Int(2);
+      /* ./../lib/standard//kernel.nit:215 */
+      REGB3 = TAG_Int(UNTAG_Int(REGB2)+UNTAG_Int(REGB3));
+      /* ./../lib/standard//string.nit:296 */
+      REGB1 = REGB3;
+    } else {
+      goto label2;
+    }
+  }
+  label2: while(0);
+  /* ./../lib/standard//string.nit:297 */
+  REGB0 = TAG_Int(1);
+  /* ./../lib/standard//kernel.nit:215 */
+  REGB0 = TAG_Int(UNTAG_Int(REGB1)+UNTAG_Int(REGB0));
+  /* ./../lib/standard//string.nit:601 */
+  fra.me.REG[1] = BOX_NativeString((char*)raw_alloc((UNTAG_Int(REGB0) * sizeof(char))));
+  /* ./../lib/standard//string.nit:298 */
+  REGB0 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 298);
+  }
+  fra.me.REG[2] = ATTR_string___AbstractString____items(fra.me.REG[0]);
+  /* ./../lib/standard//collection//array.nit:23 */
+  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
+  }
+  REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:298 */
+  REGB3 = TAG_Int(0);
+  REGB2 = TAG_Int(0);
+  /* ./../lib/standard//string.nit:587 */
+  (void)memcpy(UNBOX_NativeString(fra.me.REG[1])+UNTAG_Int(REGB2), UNBOX_NativeString(fra.me.REG[2])+UNTAG_Int(REGB3), UNTAG_Int(REGB0));;
+  /* ./../lib/standard//string.nit:299 */
+  ATTR_string___AbstractString____items(fra.me.REG[0]) = fra.me.REG[1];
+  /* ./../lib/standard//string.nit:300 */
+  ATTR_string___Buffer____capacity(fra.me.REG[0]) = REGB1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return;
+}
 void string___Buffer___append(val_t p0, val_t p1){
   struct {struct stack_frame_t me; val_t MORE_REG[4];} fra;
   val_t REGB0;
@@ -1643,168 +1484,250 @@ void string___Buffer___append(val_t p0, val_t p1){
   fra.me.REG[4] = NIT_NULL;
   fra.me.REG[0] = p0;
   fra.me.REG[1] = p1;
+  /* ./../lib/standard//string.nit:303 */
   fra.me.REG[2] = fra.me.REG[0];
   fra.me.REG[3] = fra.me.REG[1];
-  REGB0 = TAG_Bool(VAL_ISA(fra.me.REG[3], COLOR_String, ID_String)) /*cast String*/;
   /* ./../lib/standard//string.nit:305 */
+  REGB0 = TAG_Bool(VAL_ISA(fra.me.REG[3], COLOR_String, ID_String)) /*cast String*/;
   if (UNTAG_Bool(REGB0)) {
-    REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[3])!=NIT_NULL);
     /* ./../lib/standard//collection//array.nit:23 */
+    REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[3])!=NIT_NULL);
     if (UNTAG_Bool(REGB0)) {
     } else {
-      fprintf(stderr, "Uninitialized attribute %s", "_length");
-      fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-      nit_exit(1);
+      nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
     }
     REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[3]);
-    REGB1 = TAG_Bool(ATTR_string___Buffer____capacity(fra.me.REG[2])!=NIT_NULL);
     /* ./../lib/standard//string.nit:307 */
+    REGB1 = TAG_Bool(ATTR_string___Buffer____capacity(fra.me.REG[2])!=NIT_NULL);
     if (UNTAG_Bool(REGB1)) {
     } else {
-      fprintf(stderr, "Uninitialized attribute %s", "_capacity");
-      fprintf(stderr, " (%s:%d)\n", LOCATE_string, 307);
-      nit_exit(1);
+      nit_abort("Uninitialized attribute %s", "_capacity", LOCATE_string, 307);
     }
     REGB1 = ATTR_string___Buffer____capacity(fra.me.REG[2]);
-    REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[2])!=NIT_NULL);
     /* ./../lib/standard//collection//array.nit:23 */
+    REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[2])!=NIT_NULL);
     if (UNTAG_Bool(REGB2)) {
     } else {
-      fprintf(stderr, "Uninitialized attribute %s", "_length");
-      fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-      nit_exit(1);
+      nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
     }
     REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[2]);
+    /* ./../lib/standard//kernel.nit:215 */
     REGB2 = TAG_Int(UNTAG_Int(REGB2)+UNTAG_Int(REGB0));
+    /* ./../lib/standard//kernel.nit:212 */
     REGB2 = TAG_Bool(UNTAG_Int(REGB1)<UNTAG_Int(REGB2));
     /* ./../lib/standard//string.nit:307 */
     if (UNTAG_Bool(REGB2)) {
-      REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[2])!=NIT_NULL);
       /* ./../lib/standard//collection//array.nit:23 */
+      REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[2])!=NIT_NULL);
       if (UNTAG_Bool(REGB2)) {
       } else {
-        fprintf(stderr, "Uninitialized attribute %s", "_length");
-        fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-        nit_exit(1);
+        nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
       }
       REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[2]);
+      /* ./../lib/standard//kernel.nit:215 */
       REGB2 = TAG_Int(UNTAG_Int(REGB2)+UNTAG_Int(REGB0));
       /* ./../lib/standard//string.nit:307 */
       CALL_array___AbstractArray___enlarge(fra.me.REG[2])(fra.me.REG[2], REGB2);
     }
+    /* ./../lib/standard//string.nit:308 */
     fra.me.REG[3] = CALL_string___AbstractString___items(fra.me.REG[3])(fra.me.REG[3]);
     REGB2 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[2])!=NIT_NULL);
-    /* ./../lib/standard//string.nit:308 */
     if (UNTAG_Bool(REGB2)) {
     } else {
-      fprintf(stderr, "Uninitialized attribute %s", "_items");
-      fprintf(stderr, " (%s:%d)\n", LOCATE_string, 308);
-      nit_exit(1);
+      nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 308);
     }
     fra.me.REG[4] = ATTR_string___AbstractString____items(fra.me.REG[2]);
     REGB2 = TAG_Int(0);
-    REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[2])!=NIT_NULL);
     /* ./../lib/standard//collection//array.nit:23 */
+    REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[2])!=NIT_NULL);
     if (UNTAG_Bool(REGB1)) {
     } else {
-      fprintf(stderr, "Uninitialized attribute %s", "_length");
-      fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-      nit_exit(1);
+      nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
     }
     REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[2]);
     /* ./../lib/standard//string.nit:587 */
     (void)memcpy(UNBOX_NativeString(fra.me.REG[4])+UNTAG_Int(REGB1), UNBOX_NativeString(fra.me.REG[3])+UNTAG_Int(REGB2), UNTAG_Int(REGB0));;
-    REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[2]);
-    REGB0 = TAG_Int(UNTAG_Int(REGB2)+UNTAG_Int(REGB0));
+    /* ./../lib/standard//string.nit:309 */
+    REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[2]);
+    /* ./../lib/standard//kernel.nit:215 */
+    REGB0 = TAG_Int(UNTAG_Int(REGB1)+UNTAG_Int(REGB0));
     /* ./../lib/standard//string.nit:309 */
     ATTR_array___AbstractArrayRead____length(fra.me.REG[2]) = REGB0;
   } else {
-    /* ./../lib/standard//string.nit:311 */
-    CALL_SUPER_string___Buffer___append(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+    /* ./../lib/standard//string.nit:311 */
+    CALL_SUPER_string___Buffer___append(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+  }
+  stack_frame_head = fra.me.prev;
+  return;
+}
+val_t string___Buffer___to_s(val_t p0){
+  struct {struct stack_frame_t me; val_t MORE_REG[2];} fra;
+  val_t REGB0;
+  val_t REGB1;
+  val_t REGB2;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 315;
+  fra.me.meth = LOCATE_string___Buffer___to_s;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 3;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[1] = NIT_NULL;
+  fra.me.REG[2] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  /* ./../lib/standard//collection//array.nit:23 */
+  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
+  }
+  REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:318 */
+  REGB1 = TAG_Int(1);
+  /* ./../lib/standard//kernel.nit:215 */
+  REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB1));
+  /* ./../lib/standard//string.nit:601 */
+  fra.me.REG[1] = BOX_NativeString((char*)raw_alloc((UNTAG_Int(REGB1) * sizeof(char))));
+  /* ./../lib/standard//string.nit:319 */
+  REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB1)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 319);
+  }
+  fra.me.REG[2] = ATTR_string___AbstractString____items(fra.me.REG[0]);
+  REGB1 = TAG_Int(0);
+  REGB2 = TAG_Int(0);
+  /* ./../lib/standard//string.nit:587 */
+  (void)memcpy(UNBOX_NativeString(fra.me.REG[1])+UNTAG_Int(REGB2), UNBOX_NativeString(fra.me.REG[2])+UNTAG_Int(REGB1), UNTAG_Int(REGB0));;
+  /* ./../lib/standard//collection//array.nit:23 */
+  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB2)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
+  }
+  REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:322 */
+  REGB1 = TAG_Char('\0');
+  /* ./../lib/standard//string.nit:586 */
+  UNBOX_NativeString(fra.me.REG[1])[UNTAG_Int(REGB2)]=UNTAG_Char(REGB1);;
+  /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB1)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
+  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:324 */
+  fra.me.REG[1] = NEW_String_string___String___with_native(fra.me.REG[1], REGB1);
+  goto label1;
+  label1: while(0);
   stack_frame_head = fra.me.prev;
-  return;
+  return fra.me.REG[1];
 }
-void string___Buffer___enlarge(val_t p0, val_t p1){
-  struct {struct stack_frame_t me; val_t MORE_REG[2];} fra;
+val_t string___Buffer_____l(val_t p0, val_t p1){
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
   val_t REGB0;
   val_t REGB1;
   val_t REGB2;
   val_t REGB3;
+  val_t REGB4;
+  val_t REGB5;
   val_t tmp;
   fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
   fra.me.file = LOCATE_string;
-  fra.me.line = 292;
-  fra.me.meth = LOCATE_string___Buffer___enlarge;
+  fra.me.line = 327;
+  fra.me.meth = LOCATE_string___Buffer_____l;
   fra.me.has_broke = 0;
-  fra.me.REG_size = 3;
+  fra.me.REG_size = 2;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[1] = NIT_NULL;
-  fra.me.REG[2] = NIT_NULL;
   fra.me.REG[0] = p0;
-  REGB0 = p1;
-  REGB1 = TAG_Bool(ATTR_string___Buffer____capacity(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//string.nit:294 */
+  fra.me.REG[1] = p1;
+  /* ./../lib/standard//string.nit:329 */
+  REGB0 = TAG_Int(0);
+  /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_capacity");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 294);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
-  REGB1 = ATTR_string___Buffer____capacity(fra.me.REG[0]);
-  REGB2 = TAG_Bool(UNTAG_Int(REGB0)<=UNTAG_Int(REGB1));
-  /* ./../lib/standard//string.nit:295 */
+  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
   if (UNTAG_Bool(REGB2)) {
-    goto label1;
+  } else {
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
-  /* ./../lib/standard//string.nit:296 */
+  REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
+  /* ./../lib/standard//string.nit:332 */
   while(1) {
-    REGB2 = TAG_Bool(UNTAG_Int(REGB1)<=UNTAG_Int(REGB0));
-    /* ./../lib/standard//string.nit:296 */
-    if (UNTAG_Bool(REGB2)) {
-      REGB2 = TAG_Int(2);
-      REGB2 = TAG_Int(UNTAG_Int(REGB1)*UNTAG_Int(REGB2));
-      REGB3 = TAG_Int(2);
-      REGB3 = TAG_Int(UNTAG_Int(REGB2)+UNTAG_Int(REGB3));
-      REGB1 = REGB3;
-    /* ./../lib/standard//string.nit:296 */
+    /* ./../lib/standard//kernel.nit:212 */
+    REGB3 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB1));
+    /* ./../lib/standard//string.nit:332 */
+    if (UNTAG_Bool(REGB3)) {
+      /* ./../lib/standard//kernel.nit:212 */
+      REGB3 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB2));
+    } else {
+      /* ./../lib/standard//string.nit:332 */
+      REGB4 = TAG_Bool(false);
+      REGB3 = REGB4;
+    }
+    if (UNTAG_Bool(REGB3)) {
+      /* ./../lib/standard//string.nit:333 */
+      REGB3 = CALL_abstract_collection___MapRead_____bra(fra.me.REG[0])(fra.me.REG[0], REGB0);
+      /* ./../lib/standard//kernel.nit:382 */
+      REGB3 = TAG_Int((unsigned char)UNTAG_Char(REGB3));
+      /* ./../lib/standard//string.nit:334 */
+      REGB4 = CALL_abstract_collection___MapRead_____bra(fra.me.REG[1])(fra.me.REG[1], REGB0);
+      /* ./../lib/standard//kernel.nit:382 */
+      REGB4 = TAG_Int((unsigned char)UNTAG_Char(REGB4));
+      /* ./../lib/standard//kernel.nit:212 */
+      REGB5 = TAG_Bool(UNTAG_Int(REGB3)<UNTAG_Int(REGB4));
+      /* ./../lib/standard//string.nit:335 */
+      if (UNTAG_Bool(REGB5)) {
+        /* ./../lib/standard//string.nit:336 */
+        REGB5 = TAG_Bool(true);
+        goto label1;
+      } else {
+        /* ./../lib/standard//kernel.nit:212 */
+        REGB3 = TAG_Bool(UNTAG_Int(REGB4)<UNTAG_Int(REGB3));
+        /* ./../lib/standard//string.nit:337 */
+        if (UNTAG_Bool(REGB3)) {
+          /* ./../lib/standard//string.nit:338 */
+          REGB3 = TAG_Bool(false);
+          REGB5 = REGB3;
+          goto label1;
+        }
+      }
+      /* ./../lib/standard//string.nit:340 */
+      REGB3 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:215 */
+      REGB3 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB3));
+      /* ./../lib/standard//string.nit:340 */
+      REGB0 = REGB3;
     } else {
+      /* ./../lib/standard//string.nit:332 */
       goto label2;
     }
   }
   label2: while(0);
-  REGB0 = TAG_Int(1);
-  REGB0 = TAG_Int(UNTAG_Int(REGB1)+UNTAG_Int(REGB0));
-  fra.me.REG[1] = BOX_NativeString((char*)raw_alloc((UNTAG_Int(REGB0) * sizeof(char))));
-  REGB0 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//string.nit:298 */
-  if (UNTAG_Bool(REGB0)) {
-  } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 298);
-    nit_exit(1);
-  }
-  fra.me.REG[2] = ATTR_string___AbstractString____items(fra.me.REG[0]);
-  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
-  /* ./../lib/standard//collection//array.nit:23 */
-  if (UNTAG_Bool(REGB0)) {
+  /* ./../lib/standard//kernel.nit:212 */
+  REGB2 = TAG_Bool(UNTAG_Int(REGB1)<UNTAG_Int(REGB2));
+  /* ./../lib/standard//string.nit:342 */
+  if (UNTAG_Bool(REGB2)) {
+    /* ./../lib/standard//string.nit:343 */
+    REGB2 = TAG_Bool(true);
+    REGB5 = REGB2;
+    goto label1;
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    /* ./../lib/standard//string.nit:345 */
+    REGB2 = TAG_Bool(false);
+    REGB5 = REGB2;
+    goto label1;
   }
-  REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
-  REGB3 = TAG_Int(0);
-  REGB2 = TAG_Int(0);
-  /* ./../lib/standard//string.nit:587 */
-  (void)memcpy(UNBOX_NativeString(fra.me.REG[1])+UNTAG_Int(REGB2), UNBOX_NativeString(fra.me.REG[2])+UNTAG_Int(REGB3), UNTAG_Int(REGB0));;
-  /* ./../lib/standard//string.nit:299 */
-  ATTR_string___AbstractString____items(fra.me.REG[0]) = fra.me.REG[1];
-  /* ./../lib/standard//string.nit:300 */
-  ATTR_string___Buffer____capacity(fra.me.REG[0]) = REGB1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
-  return;
+  return REGB5;
 }
 void string___Buffer___init(val_t p0, int* init_table){
   int itpos2 = VAL2OBJ(p0)->vft[INIT_TABLE_POS_Buffer].i;
@@ -1820,8 +1743,8 @@ void string___Buffer___init(val_t p0, int* init_table){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
-  REGB0 = TAG_Int(5);
   /* ./../lib/standard//string.nit:352 */
+  REGB0 = TAG_Int(5);
   CALL_string___Buffer___with_capacity(fra.me.REG[0])(fra.me.REG[0], REGB0, init_table);
   stack_frame_head = fra.me.prev;
   init_table[itpos2] = 1;
@@ -1846,113 +1769,235 @@ void string___Buffer___from(val_t p0, val_t p1, int* init_table){
   fra.me.REG[2] = NIT_NULL;
   fra.me.REG[0] = p0;
   fra.me.REG[1] = p1;
-  fra.me.REG[2] = fra.me.REG[0];
   /* ./../lib/standard//string.nit:355 */
+  fra.me.REG[2] = fra.me.REG[0];
   CALL_string___StringCapable___init(fra.me.REG[0])(fra.me.REG[0], init_table);
-  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB0 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
   if (UNTAG_Bool(REGB0)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB0 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
+  /* ./../lib/standard//string.nit:357 */
   REGB1 = TAG_Int(1);
+  /* ./../lib/standard//kernel.nit:215 */
   REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB1));
   /* ./../lib/standard//string.nit:357 */
   ATTR_string___Buffer____capacity(fra.me.REG[2]) = REGB1;
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
   /* ./../lib/standard//string.nit:358 */
   ATTR_array___AbstractArrayRead____length(fra.me.REG[2]) = REGB1;
-  REGB1 = TAG_Bool(ATTR_string___Buffer____capacity(fra.me.REG[2])!=NIT_NULL);
   /* ./../lib/standard//string.nit:359 */
+  REGB1 = TAG_Bool(ATTR_string___Buffer____capacity(fra.me.REG[2])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_capacity");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 359);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_capacity", LOCATE_string, 359);
   }
   REGB1 = ATTR_string___Buffer____capacity(fra.me.REG[2]);
+  /* ./../lib/standard//string.nit:601 */
   fra.me.REG[0] = BOX_NativeString((char*)raw_alloc((UNTAG_Int(REGB1) * sizeof(char))));
   /* ./../lib/standard//string.nit:359 */
   ATTR_string___AbstractString____items(fra.me.REG[2]) = fra.me.REG[0];
+  /* ./../lib/standard//string.nit:360 */
   fra.me.REG[1] = CALL_string___AbstractString___items(fra.me.REG[1])(fra.me.REG[1]);
   REGB1 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[2])!=NIT_NULL);
-  /* ./../lib/standard//string.nit:360 */
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_items");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 360);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 360);
   }
   fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[2]);
   REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[2])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 360);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_string, 360);
+  }
+  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[2]);
+  REGB0 = TAG_Int(0);
+  REGB2 = TAG_Int(0);
+  /* ./../lib/standard//string.nit:587 */
+  (void)memcpy(UNBOX_NativeString(fra.me.REG[0])+UNTAG_Int(REGB2), UNBOX_NativeString(fra.me.REG[1])+UNTAG_Int(REGB0), UNTAG_Int(REGB1));;
+  stack_frame_head = fra.me.prev;
+  init_table[itpos3] = 1;
+  return;
+}
+void string___Buffer___with_capacity(val_t p0, val_t p1, int* init_table){
+  int itpos4 = VAL2OBJ(p0)->vft[INIT_TABLE_POS_Buffer].i;
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+  val_t REGB0;
+  val_t REGB1;
+  val_t tmp;
+  if (init_table[itpos4]) return;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 363;
+  fra.me.meth = LOCATE_string___Buffer___with_capacity;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 2;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[1] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  REGB0 = p1;
+  /* ./../lib/standard//string.nit:363 */
+  fra.me.REG[1] = fra.me.REG[0];
+  CALL_string___StringCapable___init(fra.me.REG[0])(fra.me.REG[0], init_table);
+  /* ./../lib/standard//string.nit:366 */
+  REGB1 = TAG_Int(0);
+  /* ./../lib/standard//kernel.nit:213 */
+  REGB1 = TAG_Bool(UNTAG_Int(REGB0)>=UNTAG_Int(REGB1));
+  /* ./../lib/standard//string.nit:366 */
+  if (UNTAG_Bool(REGB1)) {
+  } else {
+    nit_abort("Assert failed", NULL, LOCATE_string, 366);
+  }
+  /* ./../lib/standard//string.nit:368 */
+  REGB1 = TAG_Int(1);
+  /* ./../lib/standard//kernel.nit:215 */
+  REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB1));
+  /* ./../lib/standard//string.nit:601 */
+  fra.me.REG[0] = BOX_NativeString((char*)raw_alloc((UNTAG_Int(REGB1) * sizeof(char))));
+  /* ./../lib/standard//string.nit:368 */
+  ATTR_string___AbstractString____items(fra.me.REG[1]) = fra.me.REG[0];
+  /* ./../lib/standard//string.nit:369 */
+  ATTR_string___Buffer____capacity(fra.me.REG[1]) = REGB0;
+  /* ./../lib/standard//string.nit:370 */
+  REGB0 = TAG_Int(0);
+  ATTR_array___AbstractArrayRead____length(fra.me.REG[1]) = REGB0;
+  stack_frame_head = fra.me.prev;
+  init_table[itpos4] = 1;
+  return;
+}
+val_t string___Buffer_____eqeq(val_t p0, val_t p1){
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+  val_t REGB0;
+  val_t REGB1;
+  val_t REGB2;
+  val_t REGB3;
+  val_t REGB4;
+  val_t REGB5;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 373;
+  fra.me.meth = LOCATE_string___Buffer_____eqeq;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 2;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[1] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  fra.me.REG[1] = p1;
+  /* ./../lib/standard//string.nit:375 */
+  REGB0 = TAG_Bool((fra.me.REG[1]!=NIT_NULL) && VAL_ISA(fra.me.REG[1], COLOR_Buffer, ID_Buffer)) /*cast Buffer*/;
+  REGB0 = TAG_Bool(!UNTAG_Bool(REGB0));
+  if (UNTAG_Bool(REGB0)) {
+    REGB0 = TAG_Bool(true);
+  } else {
+    REGB1 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
+    REGB0 = REGB1;
+  }
+  if (UNTAG_Bool(REGB0)) {
+    REGB0 = TAG_Bool(false);
+    goto label1;
+  }
+  /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB1)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
+  }
+  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:377 */
+  REGB2 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
+  if (UNTAG_Bool(REGB2)) {
+    nit_abort("Reciever is null", NULL, LOCATE_string, 377);
+  }
+  /* ./../lib/standard//collection//array.nit:23 */
+  REGB2 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[1])!=NIT_NULL);
+  if (UNTAG_Bool(REGB2)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
+  }
+  REGB2 = ATTR_array___AbstractArrayRead____length(fra.me.REG[1]);
+  /* ./../lib/standard//string.nit:377 */
+  REGB3 = TAG_Bool(IS_EQUAL_OO(REGB2,REGB1));
+  if (UNTAG_Bool(REGB3)) {
+  } else {
+    /* ./../lib/standard//kernel.nit:207 */
+    REGB2 = TAG_Bool((REGB2)==(REGB1));
+    /* ./../lib/standard//string.nit:377 */
+    REGB3 = REGB2;
+  }
+  REGB3 = TAG_Bool(!UNTAG_Bool(REGB3));
+  if (UNTAG_Bool(REGB3)) {
+    REGB3 = TAG_Bool(false);
+    REGB0 = REGB3;
+    goto label1;
+  }
+  /* ./../lib/standard//string.nit:378 */
+  REGB3 = TAG_Int(0);
+  /* ./../lib/standard//string.nit:379 */
+  REGB2 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[0])!=NIT_NULL);
+  if (UNTAG_Bool(REGB2)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 379);
+  }
+  fra.me.REG[0] = ATTR_string___AbstractString____items(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:380 */
+  REGB2 = TAG_Bool(ATTR_string___AbstractString____items(fra.me.REG[1])!=NIT_NULL);
+  if (UNTAG_Bool(REGB2)) {
+  } else {
+    nit_abort("Uninitialized attribute %s", "_items", LOCATE_string, 380);
   }
-  REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[2]);
-  REGB0 = TAG_Int(0);
-  REGB2 = TAG_Int(0);
-  /* ./../lib/standard//string.nit:587 */
-  (void)memcpy(UNBOX_NativeString(fra.me.REG[0])+UNTAG_Int(REGB2), UNBOX_NativeString(fra.me.REG[1])+UNTAG_Int(REGB0), UNTAG_Int(REGB1));;
-  stack_frame_head = fra.me.prev;
-  init_table[itpos3] = 1;
-  return;
-}
-void string___Buffer___with_capacity(val_t p0, val_t p1, int* init_table){
-  int itpos4 = VAL2OBJ(p0)->vft[INIT_TABLE_POS_Buffer].i;
-  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
-  val_t REGB0;
-  val_t REGB1;
-  val_t tmp;
-  if (init_table[itpos4]) return;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 363;
-  fra.me.meth = LOCATE_string___Buffer___with_capacity;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 2;
-  fra.me.REG[0] = NIT_NULL;
-  fra.me.REG[1] = NIT_NULL;
-  fra.me.REG[0] = p0;
-  REGB0 = p1;
-  fra.me.REG[1] = fra.me.REG[0];
-  /* ./../lib/standard//string.nit:363 */
-  CALL_string___StringCapable___init(fra.me.REG[0])(fra.me.REG[0], init_table);
-  REGB1 = TAG_Int(0);
-  REGB1 = TAG_Bool(UNTAG_Int(REGB0)>=UNTAG_Int(REGB1));
-  /* ./../lib/standard//string.nit:366 */
-  if (UNTAG_Bool(REGB1)) {
-  } else {
-    fprintf(stderr, "Assert failed");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 366);
-    nit_exit(1);
+  fra.me.REG[1] = ATTR_string___AbstractString____items(fra.me.REG[1]);
+  /* ./../lib/standard//string.nit:381 */
+  while(1) {
+    /* ./../lib/standard//kernel.nit:212 */
+    REGB2 = TAG_Bool(UNTAG_Int(REGB3)<UNTAG_Int(REGB1));
+    /* ./../lib/standard//string.nit:381 */
+    if (UNTAG_Bool(REGB2)) {
+      /* ./../lib/standard//string.nit:585 */
+      REGB2 = TAG_Char(UNBOX_NativeString(fra.me.REG[0])[UNTAG_Int(REGB3)]);
+      REGB4 = TAG_Char(UNBOX_NativeString(fra.me.REG[1])[UNTAG_Int(REGB3)]);
+      /* ./../lib/standard//string.nit:382 */
+      REGB5 = TAG_Bool(IS_EQUAL_OO(REGB2,REGB4));
+      if (UNTAG_Bool(REGB5)) {
+      } else {
+        /* ./../lib/standard//kernel.nit:347 */
+        REGB4 = TAG_Bool((REGB2)==(REGB4));
+        /* ./../lib/standard//string.nit:382 */
+        REGB5 = REGB4;
+      }
+      REGB5 = TAG_Bool(!UNTAG_Bool(REGB5));
+      if (UNTAG_Bool(REGB5)) {
+        REGB5 = TAG_Bool(false);
+        REGB0 = REGB5;
+        goto label1;
+      }
+      /* ./../lib/standard//string.nit:383 */
+      REGB5 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:215 */
+      REGB5 = TAG_Int(UNTAG_Int(REGB3)+UNTAG_Int(REGB5));
+      /* ./../lib/standard//string.nit:383 */
+      REGB3 = REGB5;
+    } else {
+      /* ./../lib/standard//string.nit:381 */
+      goto label2;
+    }
   }
-  REGB1 = TAG_Int(1);
-  REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB1));
-  fra.me.REG[0] = BOX_NativeString((char*)raw_alloc((UNTAG_Int(REGB1) * sizeof(char))));
-  /* ./../lib/standard//string.nit:368 */
-  ATTR_string___AbstractString____items(fra.me.REG[1]) = fra.me.REG[0];
-  /* ./../lib/standard//string.nit:369 */
-  ATTR_string___Buffer____capacity(fra.me.REG[1]) = REGB0;
-  REGB0 = TAG_Int(0);
-  /* ./../lib/standard//string.nit:370 */
-  ATTR_array___AbstractArrayRead____length(fra.me.REG[1]) = REGB0;
+  label2: while(0);
+  /* ./../lib/standard//string.nit:385 */
+  REGB3 = TAG_Bool(true);
+  REGB0 = REGB3;
+  goto label1;
+  label1: while(0);
   stack_frame_head = fra.me.prev;
-  init_table[itpos4] = 1;
-  return;
+  return REGB0;
 }
 val_t string___Buffer___capacity(val_t p0){
   struct {struct stack_frame_t me;} fra;
@@ -1966,13 +2011,11 @@ val_t string___Buffer___capacity(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
-  REGB0 = TAG_Bool(ATTR_string___Buffer____capacity(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//string.nit:388 */
+  REGB0 = TAG_Bool(ATTR_string___Buffer____capacity(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB0)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_capacity");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 388);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_capacity", LOCATE_string, 388);
   }
   REGB0 = ATTR_string___Buffer____capacity(fra.me.REG[0]);
   stack_frame_head = fra.me.prev;
@@ -1989,8 +2032,8 @@ val_t string___Object___to_s(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
-  fra.me.REG[0] = CALL_string___Object___inspect(fra.me.REG[0])(fra.me.REG[0]);
   /* ./../lib/standard//string.nit:399 */
+  fra.me.REG[0] = CALL_string___Object___inspect(fra.me.REG[0])(fra.me.REG[0]);
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
@@ -2007,6 +2050,7 @@ val_t string___Object___inspect(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:405 */
   fra.me.REG[0] = CALL_string___Object___inspect_head(fra.me.REG[0])(fra.me.REG[0]);
   /* ./../lib/standard//string.nit:407 */
   goto label1;
@@ -2030,9 +2074,9 @@ val_t string___Object___inspect_head(val_t p0){
   fra.me.REG[1] = NIT_NULL;
   fra.me.REG[2] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:414 */
   REGB0 = TAG_Int(3);
   fra.me.REG[1] = NEW_Array_array___Array___with_capacity(REGB0);
-  /* ./../lib/standard//string.nit:414 */
   if (!once_value_1) {
     fra.me.REG[2] = BOX_NativeString("<");
     REGB0 = TAG_Int(1);
@@ -2040,10 +2084,11 @@ val_t string___Object___inspect_head(val_t p0){
     once_value_1 = fra.me.REG[2];
     register_static_object(&once_value_1);
   } else fra.me.REG[2] = once_value_1;
-  array___Array___add(fra.me.REG[1], fra.me.REG[2]);
+  fra.me.REG[2] = fra.me.REG[2];
+  CALL_abstract_collection___SimpleCollection___add(fra.me.REG[1])(fra.me.REG[1], fra.me.REG[2]);
   REGB0 = CALL_kernel___Object___object_id(fra.me.REG[0])(fra.me.REG[0]);
   fra.me.REG[0] = CALL_string___Int___to_hex(REGB0)(REGB0);
-  array___Array___add(fra.me.REG[1], fra.me.REG[0]);
+  CALL_abstract_collection___SimpleCollection___add(fra.me.REG[1])(fra.me.REG[1], fra.me.REG[0]);
   if (!once_value_2) {
     fra.me.REG[0] = BOX_NativeString("");
     REGB0 = TAG_Int(0);
@@ -2051,7 +2096,8 @@ val_t string___Object___inspect_head(val_t p0){
     once_value_2 = fra.me.REG[0];
     register_static_object(&once_value_2);
   } else fra.me.REG[0] = once_value_2;
-  array___Array___add(fra.me.REG[1], fra.me.REG[0]);
+  fra.me.REG[0] = fra.me.REG[0];
+  CALL_abstract_collection___SimpleCollection___add(fra.me.REG[1])(fra.me.REG[1], fra.me.REG[0]);
   fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
   goto label3;
   label3: while(0);
@@ -2069,9 +2115,9 @@ val_t string___Object___args(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:419 */
   fra.me.REG[0] = CALL_kernel___Object___sys(fra.me.REG[0])(fra.me.REG[0]);
   fra.me.REG[0] = CALL_string___Object___args(fra.me.REG[0])(fra.me.REG[0]);
-  /* ./../lib/standard//string.nit:419 */
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
@@ -2105,9 +2151,11 @@ val_t string___Bool___to_s(val_t p0){
         once_value_2 = fra.me.REG[0];
         register_static_object(&once_value_2);
       } else fra.me.REG[0] = once_value_2;
+      fra.me.REG[0] = fra.me.REG[0];
       once_value_1 = fra.me.REG[0];
       register_static_object(&once_value_1);
     } else fra.me.REG[0] = once_value_1;
+    fra.me.REG[0] = fra.me.REG[0];
     goto label3;
   } else {
     /* ./../lib/standard//string.nit:429 */
@@ -2119,9 +2167,11 @@ val_t string___Bool___to_s(val_t p0){
         once_value_5 = fra.me.REG[1];
         register_static_object(&once_value_5);
       } else fra.me.REG[1] = once_value_5;
+      fra.me.REG[1] = fra.me.REG[1];
       once_value_4 = fra.me.REG[1];
       register_static_object(&once_value_4);
     } else fra.me.REG[1] = once_value_4;
+    fra.me.REG[1] = fra.me.REG[1];
     fra.me.REG[0] = fra.me.REG[1];
     goto label3;
   }
@@ -2129,29 +2179,6 @@ val_t string___Bool___to_s(val_t p0){
   stack_frame_head = fra.me.prev;
   return fra.me.REG[0];
 }
-val_t string___Int___to_s(val_t p0){
-  struct {struct stack_frame_t me;} fra;
-  val_t REGB0;
-  val_t REGB1;
-  val_t REGB2;
-  val_t tmp;
-  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
-  fra.me.file = LOCATE_string;
-  fra.me.line = 459;
-  fra.me.meth = LOCATE_string___Int___to_s;
-  fra.me.has_broke = 0;
-  fra.me.REG_size = 1;
-  fra.me.REG[0] = NIT_NULL;
-  REGB0 = p0;
-  REGB1 = TAG_Int(10);
-  REGB2 = TAG_Bool(true);
-  fra.me.REG[0] = CALL_string___Int___to_base(REGB0)(REGB0, REGB1, REGB2);
-  /* ./../lib/standard//string.nit:460 */
-  goto label1;
-  label1: while(0);
-  stack_frame_head = fra.me.prev;
-  return fra.me.REG[0];
-}
 void string___Int___fill_buffer(val_t p0, val_t p1, val_t p2, val_t p3){
   struct {struct stack_frame_t me;} fra;
   val_t REGB0;
@@ -2171,64 +2198,77 @@ void string___Int___fill_buffer(val_t p0, val_t p1, val_t p2, val_t p3){
   fra.me.REG[0] = p1;
   REGB1 = p2;
   REGB2 = p3;
+  /* ./../lib/standard//string.nit:441 */
   REGB2 = TAG_Int(0);
+  /* ./../lib/standard//kernel.nit:212 */
   REGB2 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB2));
   /* ./../lib/standard//string.nit:441 */
   if (UNTAG_Bool(REGB2)) {
+    /* ./../lib/standard//kernel.nit:216 */
     REGB2 = TAG_Int(-UNTAG_Int(REGB0));
+    /* ./../lib/standard//string.nit:443 */
     REGB3 = TAG_Int(0);
     REGB4 = TAG_Char('-');
-    /* ./../lib/standard//string.nit:443 */
     CALL_abstract_collection___Map_____braeq(fra.me.REG[0])(fra.me.REG[0], REGB3, REGB4);
   } else {
+    /* ./../lib/standard//string.nit:444 */
     REGB4 = TAG_Int(0);
     REGB3 = TAG_Bool(IS_EQUAL_OO(REGB0,REGB4));
-    /* ./../lib/standard//string.nit:444 */
     if (UNTAG_Bool(REGB3)) {
     } else {
+      /* ./../lib/standard//kernel.nit:207 */
       REGB4 = TAG_Bool((REGB0)==(REGB4));
+      /* ./../lib/standard//string.nit:444 */
       REGB3 = REGB4;
-    /* ./../lib/standard//string.nit:444 */
     }
     if (UNTAG_Bool(REGB3)) {
+      /* ./../lib/standard//string.nit:445 */
       REGB3 = TAG_Int(0);
       REGB4 = TAG_Char('0');
-      /* ./../lib/standard//string.nit:445 */
       CALL_abstract_collection___Map_____braeq(fra.me.REG[0])(fra.me.REG[0], REGB3, REGB4);
       /* ./../lib/standard//string.nit:446 */
       goto label1;
     } else {
+      /* ./../lib/standard//string.nit:448 */
       REGB2 = REGB0;
-    /* ./../lib/standard//string.nit:448 */
     }
   }
+  /* ./../lib/standard//string.nit:451 */
   REGB0 = CALL_kernel___Int___digit_count(REGB0)(REGB0, REGB1);
   REGB4 = TAG_Int(1);
+  /* ./../lib/standard//kernel.nit:217 */
   REGB4 = TAG_Int(UNTAG_Int(REGB0)-UNTAG_Int(REGB4));
   /* ./../lib/standard//string.nit:452 */
   while(1) {
     REGB0 = TAG_Int(0);
+    /* ./../lib/standard//kernel.nit:213 */
     REGB0 = TAG_Bool(UNTAG_Int(REGB4)>=UNTAG_Int(REGB0));
     /* ./../lib/standard//string.nit:452 */
     if (UNTAG_Bool(REGB0)) {
       REGB0 = TAG_Int(0);
+      /* ./../lib/standard//kernel.nit:214 */
       REGB0 = TAG_Bool(UNTAG_Int(REGB2)>UNTAG_Int(REGB0));
-    /* ./../lib/standard//string.nit:452 */
     } else {
+      /* ./../lib/standard//string.nit:452 */
       REGB3 = TAG_Bool(false);
       REGB0 = REGB3;
     }
     if (UNTAG_Bool(REGB0)) {
+      /* ./../lib/standard//kernel.nit:220 */
       REGB0 = TAG_Int(UNTAG_Int(REGB2)%UNTAG_Int(REGB1));
-      REGB0 = CALL_kernel___Int___to_c(REGB0)(REGB0);
       /* ./../lib/standard//string.nit:453 */
+      REGB0 = CALL_kernel___Int___to_c(REGB0)(REGB0);
       CALL_abstract_collection___Map_____braeq(fra.me.REG[0])(fra.me.REG[0], REGB4, REGB0);
+      /* ./../lib/standard//kernel.nit:219 */
       REGB0 = TAG_Int(UNTAG_Int(REGB2)/UNTAG_Int(REGB1));
+      /* ./../lib/standard//string.nit:454 */
       REGB2 = REGB0;
+      /* ./../lib/standard//string.nit:455 */
       REGB0 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:217 */
       REGB0 = TAG_Int(UNTAG_Int(REGB4)-UNTAG_Int(REGB0));
+      /* ./../lib/standard//string.nit:455 */
       REGB4 = REGB0;
-    /* ./../lib/standard//string.nit:455 */
     } else {
       /* ./../lib/standard//string.nit:452 */
       goto label2;
@@ -2239,6 +2279,29 @@ void string___Int___fill_buffer(val_t p0, val_t p1, val_t p2, val_t p3){
   stack_frame_head = fra.me.prev;
   return;
 }
+val_t string___Int___to_s(val_t p0){
+  struct {struct stack_frame_t me;} fra;
+  val_t REGB0;
+  val_t REGB1;
+  val_t REGB2;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_string;
+  fra.me.line = 459;
+  fra.me.meth = LOCATE_string___Int___to_s;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  REGB0 = p0;
+  /* ./../lib/standard//string.nit:460 */
+  REGB1 = TAG_Int(10);
+  REGB2 = TAG_Bool(true);
+  fra.me.REG[0] = CALL_string___Int___to_base(REGB0)(REGB0, REGB1, REGB2);
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
 val_t string___Int___to_hex(val_t p0){
   struct {struct stack_frame_t me;} fra;
   val_t REGB0;
@@ -2253,10 +2316,10 @@ val_t string___Int___to_hex(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   REGB0 = p0;
+  /* ./../lib/standard//string.nit:463 */
   REGB1 = TAG_Int(16);
   REGB2 = TAG_Bool(false);
   fra.me.REG[0] = CALL_string___Int___to_base(REGB0)(REGB0, REGB1, REGB2);
-  /* ./../lib/standard//string.nit:463 */
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
@@ -2281,6 +2344,7 @@ val_t string___Int___to_base(val_t p0, val_t p1, val_t p2){
   REGB0 = p0;
   REGB1 = p1;
   REGB2 = p2;
+  /* ./../lib/standard//string.nit:468 */
   REGB3 = CALL_kernel___Int___digit_count(REGB0)(REGB0, REGB1);
   /* ./../lib/standard//string.nit:469 */
   if (!once_value_1) {
@@ -2290,12 +2354,13 @@ val_t string___Int___to_base(val_t p0, val_t p1, val_t p2){
     once_value_1 = fra.me.REG[0];
     register_static_object(&once_value_1);
   } else fra.me.REG[0] = once_value_1;
+  fra.me.REG[0] = fra.me.REG[0];
   fra.me.REG[0] = CALL_string___String_____star(fra.me.REG[0])(fra.me.REG[0], REGB3);
   fra.me.REG[0] = NEW_Buffer_string___Buffer___from(fra.me.REG[0]);
   /* ./../lib/standard//string.nit:470 */
   CALL_string___Int___fill_buffer(REGB0)(REGB0, fra.me.REG[0], REGB1, REGB2);
-  fra.me.REG[0] = CALL_string___Object___to_s(fra.me.REG[0])(fra.me.REG[0]);
   /* ./../lib/standard//string.nit:471 */
+  fra.me.REG[0] = CALL_string___Object___to_s(fra.me.REG[0])(fra.me.REG[0]);
   goto label2;
   label2: while(0);
   stack_frame_head = fra.me.prev;
@@ -2313,9 +2378,9 @@ val_t string___Float___to_s(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:476 */
   REGB0 = TAG_Int(6);
   fra.me.REG[0] = CALL_string___Float___to_precision(fra.me.REG[0])(fra.me.REG[0], REGB0);
-  /* ./../lib/standard//string.nit:476 */
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
@@ -2342,49 +2407,63 @@ val_t string___Float___to_precision(val_t p0, val_t p1){
   fra.me.REG[3] = NIT_NULL;
   fra.me.REG[0] = p0;
   REGB0 = p1;
+  /* ./../lib/standard//string.nit:481 */
   REGB1 = TAG_Int(0);
   REGB2 = TAG_Bool(IS_EQUAL_OO(REGB0,REGB1));
-  /* ./../lib/standard//string.nit:481 */
   if (UNTAG_Bool(REGB2)) {
   } else {
+    /* ./../lib/standard//kernel.nit:207 */
     REGB1 = TAG_Bool((REGB0)==(REGB1));
+    /* ./../lib/standard//string.nit:481 */
     REGB2 = REGB1;
-  /* ./../lib/standard//string.nit:481 */
   }
   if (UNTAG_Bool(REGB2)) {
+    /* ./../lib/standard//kernel.nit:196 */
     REGB2 = TAG_Int((bigint)UNBOX_Float(fra.me.REG[0]));
-    fra.me.REG[1] = CALL_string___Object___to_s(REGB2)(REGB2);
     /* ./../lib/standard//string.nit:481 */
+    fra.me.REG[1] = CALL_string___Object___to_s(REGB2)(REGB2);
     goto label1;
   }
+  /* ./../lib/standard//kernel.nit:196 */
   REGB2 = TAG_Int((bigint)UNBOX_Float(fra.me.REG[0]));
+  /* ./../lib/standard//string.nit:484 */
   fra.me.REG[2] = BOX_Float(1.0);
   /* ./../lib/standard//string.nit:485 */
   while(1) {
     REGB1 = TAG_Int(0);
+    /* ./../lib/standard//kernel.nit:214 */
     REGB1 = TAG_Bool(UNTAG_Int(REGB0)>UNTAG_Int(REGB1));
     /* ./../lib/standard//string.nit:485 */
     if (UNTAG_Bool(REGB1)) {
+      /* ./../lib/standard//string.nit:486 */
       fra.me.REG[3] = BOX_Float(10.0);
+      /* ./../lib/standard//kernel.nit:193 */
       fra.me.REG[3] = BOX_Float(UNBOX_Float(fra.me.REG[2])*UNBOX_Float(fra.me.REG[3]));
+      /* ./../lib/standard//string.nit:486 */
       fra.me.REG[2] = fra.me.REG[3];
+      /* ./../lib/standard//string.nit:487 */
       REGB1 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:217 */
       REGB1 = TAG_Int(UNTAG_Int(REGB0)-UNTAG_Int(REGB1));
+      /* ./../lib/standard//string.nit:487 */
       REGB0 = REGB1;
-    /* ./../lib/standard//string.nit:487 */
     } else {
       /* ./../lib/standard//string.nit:485 */
       goto label2;
     }
   }
   label2: while(0);
+  /* ./../lib/standard//kernel.nit:224 */
   fra.me.REG[3] = BOX_Float((float)UNTAG_Int(REGB2));
+  /* ./../lib/standard//kernel.nit:192 */
   fra.me.REG[3] = BOX_Float(UNBOX_Float(fra.me.REG[0])-UNBOX_Float(fra.me.REG[3]));
+  /* ./../lib/standard//kernel.nit:193 */
   fra.me.REG[2] = BOX_Float(UNBOX_Float(fra.me.REG[3])*UNBOX_Float(fra.me.REG[2]));
+  /* ./../lib/standard//kernel.nit:196 */
   REGB0 = TAG_Int((bigint)UNBOX_Float(fra.me.REG[2]));
+  /* ./../lib/standard//string.nit:490 */
   REGB1 = TAG_Int(5);
   fra.me.REG[2] = NEW_Array_array___Array___with_capacity(REGB1);
-  /* ./../lib/standard//string.nit:490 */
   if (!once_value_3) {
     fra.me.REG[3] = BOX_NativeString("");
     REGB1 = TAG_Int(0);
@@ -2392,9 +2471,10 @@ val_t string___Float___to_precision(val_t p0, val_t p1){
     once_value_3 = fra.me.REG[3];
     register_static_object(&once_value_3);
   } else fra.me.REG[3] = once_value_3;
-  array___Array___add(fra.me.REG[2], fra.me.REG[3]);
+  fra.me.REG[3] = fra.me.REG[3];
+  CALL_abstract_collection___SimpleCollection___add(fra.me.REG[2])(fra.me.REG[2], fra.me.REG[3]);
   fra.me.REG[3] = CALL_string___Object___to_s(REGB2)(REGB2);
-  array___Array___add(fra.me.REG[2], fra.me.REG[3]);
+  CALL_abstract_collection___SimpleCollection___add(fra.me.REG[2])(fra.me.REG[2], fra.me.REG[3]);
   if (!once_value_4) {
     fra.me.REG[3] = BOX_NativeString(".");
     REGB2 = TAG_Int(1);
@@ -2402,9 +2482,10 @@ val_t string___Float___to_precision(val_t p0, val_t p1){
     once_value_4 = fra.me.REG[3];
     register_static_object(&once_value_4);
   } else fra.me.REG[3] = once_value_4;
-  array___Array___add(fra.me.REG[2], fra.me.REG[3]);
+  fra.me.REG[3] = fra.me.REG[3];
+  CALL_abstract_collection___SimpleCollection___add(fra.me.REG[2])(fra.me.REG[2], fra.me.REG[3]);
   fra.me.REG[3] = CALL_string___Object___to_s(REGB0)(REGB0);
-  array___Array___add(fra.me.REG[2], fra.me.REG[3]);
+  CALL_abstract_collection___SimpleCollection___add(fra.me.REG[2])(fra.me.REG[2], fra.me.REG[3]);
   if (!once_value_5) {
     fra.me.REG[3] = BOX_NativeString("");
     REGB0 = TAG_Int(0);
@@ -2412,7 +2493,8 @@ val_t string___Float___to_precision(val_t p0, val_t p1){
     once_value_5 = fra.me.REG[3];
     register_static_object(&once_value_5);
   } else fra.me.REG[3] = once_value_5;
-  array___Array___add(fra.me.REG[2], fra.me.REG[3]);
+  fra.me.REG[3] = fra.me.REG[3];
+  CALL_abstract_collection___SimpleCollection___add(fra.me.REG[2])(fra.me.REG[2], fra.me.REG[3]);
   fra.me.REG[2] = CALL_string___Object___to_s(fra.me.REG[2])(fra.me.REG[2]);
   fra.me.REG[1] = fra.me.REG[2];
   goto label1;
@@ -2433,76 +2515,83 @@ val_t string___Char___to_s(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   REGB0 = p0;
+  /* ./../lib/standard//string.nit:497 */
   REGB1 = TAG_Int(1);
   fra.me.REG[0] = NEW_Buffer_string___Buffer___with_capacity(REGB1);
-  REGB1 = TAG_Int(0);
   /* ./../lib/standard//string.nit:498 */
+  REGB1 = TAG_Int(0);
   CALL_abstract_collection___Map_____braeq(fra.me.REG[0])(fra.me.REG[0], REGB1, REGB0);
-  fra.me.REG[0] = CALL_string___Object___to_s(fra.me.REG[0])(fra.me.REG[0]);
   /* ./../lib/standard//string.nit:499 */
+  fra.me.REG[0] = CALL_string___Object___to_s(fra.me.REG[0])(fra.me.REG[0]);
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
   return fra.me.REG[0];
 }
 val_t string___Collection___to_s(val_t p0){
-  struct {struct stack_frame_t me; val_t MORE_REG[2];} fra;
-  val_t REGB0;
-  val_t REGB1;
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
   val_t tmp;
   fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
   fra.me.file = LOCATE_string;
   fra.me.line = 504;
   fra.me.meth = LOCATE_string___Collection___to_s;
   fra.me.has_broke = 0;
-  fra.me.REG_size = 3;
+  fra.me.REG_size = 2;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[1] = NIT_NULL;
-  fra.me.REG[2] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:507 */
   fra.me.REG[1] = NEW_Buffer_string___Buffer___init();
-  fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
-  /* ./../lib/standard//string.nit:508 */
-  while(1) {
-    REGB0 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[0])(fra.me.REG[0]);
+  CALL_abstract_collection___Collection___iterate(fra.me.REG[0])(fra.me.REG[0], (&(fra.me)), ((fun_t)OC_string___Collection___to_s_1));
+  /* ./../lib/standard//string.nit:509 */
+  fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
+  goto label2;
+  label2: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[1];
+}
+  void OC_string___Collection___to_s_1(struct stack_frame_t *closctx, val_t p0, struct stack_frame_t *closctx_param, fun_t clos_fun0){
+    struct {struct stack_frame_t me;} fra;
+    val_t REGB0;
+    val_t REGB1;
+    fun_t CREG[1];
+    val_t tmp;
+    /* ./../lib/standard//string.nit:508 */
+    fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+    fra.me.file = LOCATE_string;
+    fra.me.line = 0;
+    fra.me.meth = LOCATE_string___Collection___to_s;
+    fra.me.has_broke = 0;
+    fra.me.REG_size = 1;
+    fra.me.REG[0] = NIT_NULL;
+    fra.me.closure_ctx = closctx_param;
+    fra.me.closure_funs = CREG;
+    fra.me.REG[0] = p0;
+    CREG[0] = clos_fun0;
+    REGB0 = TAG_Bool(fra.me.REG[0]==NIT_NULL);
     if (UNTAG_Bool(REGB0)) {
-      fra.me.REG[2] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
-      REGB0 = TAG_Bool(fra.me.REG[2]==NIT_NULL);
-      if (UNTAG_Bool(REGB0)) {
+    } else {
+      REGB1 = TAG_Bool(fra.me.REG[0]==NIT_NULL);
+      if (UNTAG_Bool(REGB1)) {
+        REGB1 = TAG_Bool(false);
+        REGB0 = REGB1;
       } else {
-        REGB1 = TAG_Bool(fra.me.REG[2]==NIT_NULL);
-        if (UNTAG_Bool(REGB1)) {
-          REGB1 = TAG_Bool(false);
-          REGB0 = REGB1;
-        } else {
-          REGB1 = CALL_kernel___Object_____eqeq(fra.me.REG[2])(fra.me.REG[2], NIT_NULL);
-          REGB0 = REGB1;
-        }
+        REGB1 = CALL_kernel___Object_____eqeq(fra.me.REG[0])(fra.me.REG[0], NIT_NULL);
+        REGB0 = REGB1;
       }
-      REGB0 = TAG_Bool(!UNTAG_Bool(REGB0));
+    }
+    REGB0 = TAG_Bool(!UNTAG_Bool(REGB0));
+    if (UNTAG_Bool(REGB0)) {
+      REGB0 = TAG_Bool(fra.me.REG[0]==NIT_NULL);
       if (UNTAG_Bool(REGB0)) {
-        REGB0 = TAG_Bool(fra.me.REG[2]==NIT_NULL);
-        if (UNTAG_Bool(REGB0)) {
-          fprintf(stderr, "Reciever is null");
-          fprintf(stderr, " (%s:%d)\n", LOCATE_string, 508);
-          nit_exit(1);
-        }
-        fra.me.REG[2] = CALL_string___Object___to_s(fra.me.REG[2])(fra.me.REG[2]);
-        CALL_abstract_collection___Sequence___append(fra.me.REG[1])(fra.me.REG[1], fra.me.REG[2]);
+        nit_abort("Reciever is null", NULL, LOCATE_string, 508);
       }
-    } else {
-      goto label1;
+      fra.me.REG[0] = CALL_string___Object___to_s(fra.me.REG[0])(fra.me.REG[0]);
+      CALL_abstract_collection___Sequence___append(closctx->REG[1])(closctx->REG[1], fra.me.REG[0]);
     }
-    CALL_abstract_collection___Iterator___next(fra.me.REG[0])(fra.me.REG[0]);
+    stack_frame_head = fra.me.prev;
+    return;
   }
-  label1: while(0);
-  fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
-  /* ./../lib/standard//string.nit:509 */
-  goto label2;
-  label2: while(0);
-  stack_frame_head = fra.me.prev;
-  return fra.me.REG[1];
-}
 val_t string___Collection___join(val_t p0, val_t p1){
   struct {struct stack_frame_t me; val_t MORE_REG[5];} fra;
   val_t REGB0;
@@ -2523,8 +2612,8 @@ val_t string___Collection___join(val_t p0, val_t p1){
   fra.me.REG[5] = NIT_NULL;
   fra.me.REG[0] = p0;
   fra.me.REG[1] = p1;
-  REGB0 = CALL_abstract_collection___Collection___is_empty(fra.me.REG[0])(fra.me.REG[0]);
   /* ./../lib/standard//string.nit:515 */
+  REGB0 = CALL_abstract_collection___Collection___is_empty(fra.me.REG[0])(fra.me.REG[0]);
   if (UNTAG_Bool(REGB0)) {
     if (!once_value_1) {
       fra.me.REG[2] = BOX_NativeString("");
@@ -2533,13 +2622,17 @@ val_t string___Collection___join(val_t p0, val_t p1){
       once_value_1 = fra.me.REG[2];
       register_static_object(&once_value_1);
     } else fra.me.REG[2] = once_value_1;
+    fra.me.REG[2] = fra.me.REG[2];
     goto label2;
   }
+  /* ./../lib/standard//string.nit:517 */
   fra.me.REG[3] = NEW_Buffer_string___Buffer___init();
+  /* ./../lib/standard//string.nit:520 */
   fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:521 */
   fra.me.REG[4] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
-  REGB0 = TAG_Bool(fra.me.REG[4]==NIT_NULL);
   /* ./../lib/standard//string.nit:522 */
+  REGB0 = TAG_Bool(fra.me.REG[4]==NIT_NULL);
   if (UNTAG_Bool(REGB0)) {
   } else {
     REGB1 = TAG_Bool(fra.me.REG[4]==NIT_NULL);
@@ -2555,9 +2648,7 @@ val_t string___Collection___join(val_t p0, val_t p1){
   if (UNTAG_Bool(REGB0)) {
     REGB0 = TAG_Bool(fra.me.REG[4]==NIT_NULL);
     if (UNTAG_Bool(REGB0)) {
-      fprintf(stderr, "Reciever is null");
-      fprintf(stderr, " (%s:%d)\n", LOCATE_string, 522);
-      nit_exit(1);
+      nit_abort("Reciever is null", NULL, LOCATE_string, 522);
     }
     fra.me.REG[5] = CALL_string___Object___to_s(fra.me.REG[4])(fra.me.REG[4]);
     CALL_abstract_collection___Sequence___append(fra.me.REG[3])(fra.me.REG[3], fra.me.REG[5]);
@@ -2570,10 +2661,11 @@ val_t string___Collection___join(val_t p0, val_t p1){
     if (UNTAG_Bool(REGB0)) {
       /* ./../lib/standard//string.nit:527 */
       CALL_abstract_collection___Sequence___append(fra.me.REG[3])(fra.me.REG[3], fra.me.REG[1]);
+      /* ./../lib/standard//string.nit:528 */
       fra.me.REG[5] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
       fra.me.REG[4] = fra.me.REG[5];
-      REGB0 = TAG_Bool(fra.me.REG[4]==NIT_NULL);
       /* ./../lib/standard//string.nit:529 */
+      REGB0 = TAG_Bool(fra.me.REG[4]==NIT_NULL);
       if (UNTAG_Bool(REGB0)) {
       } else {
         REGB1 = TAG_Bool(fra.me.REG[4]==NIT_NULL);
@@ -2589,9 +2681,7 @@ val_t string___Collection___join(val_t p0, val_t p1){
       if (UNTAG_Bool(REGB0)) {
         REGB0 = TAG_Bool(fra.me.REG[4]==NIT_NULL);
         if (UNTAG_Bool(REGB0)) {
-          fprintf(stderr, "Reciever is null");
-          fprintf(stderr, " (%s:%d)\n", LOCATE_string, 529);
-          nit_exit(1);
+          nit_abort("Reciever is null", NULL, LOCATE_string, 529);
         }
         fra.me.REG[5] = CALL_string___Object___to_s(fra.me.REG[4])(fra.me.REG[4]);
         CALL_abstract_collection___Sequence___append(fra.me.REG[3])(fra.me.REG[3], fra.me.REG[5]);
@@ -2604,9 +2694,9 @@ val_t string___Collection___join(val_t p0, val_t p1){
     }
   }
   label3: while(0);
+  /* ./../lib/standard//string.nit:532 */
   fra.me.REG[3] = CALL_string___Object___to_s(fra.me.REG[3])(fra.me.REG[3]);
   fra.me.REG[2] = fra.me.REG[3];
-  /* ./../lib/standard//string.nit:532 */
   goto label2;
   label2: while(0);
   stack_frame_head = fra.me.prev;
@@ -2630,62 +2720,62 @@ val_t string___Array___to_s(val_t p0){
   fra.me.REG[1] = NIT_NULL;
   fra.me.REG[2] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:540 */
   fra.me.REG[1] = NEW_Buffer_string___Buffer___init();
+  /* ./../lib/standard//string.nit:541 */
   REGB0 = TAG_Int(0);
-  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   /* ./../lib/standard//collection//array.nit:23 */
+  REGB1 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[0])!=NIT_NULL);
   if (UNTAG_Bool(REGB1)) {
   } else {
-    fprintf(stderr, "Uninitialized attribute %s", "_length");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_array, 23);
-    nit_exit(1);
+    nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 23);
   }
   REGB1 = ATTR_array___AbstractArrayRead____length(fra.me.REG[0]);
   /* ./../lib/standard//string.nit:543 */
   while(1) {
+    /* ./../lib/standard//kernel.nit:212 */
     REGB2 = TAG_Bool(UNTAG_Int(REGB0)<UNTAG_Int(REGB1));
     /* ./../lib/standard//string.nit:543 */
     if (UNTAG_Bool(REGB2)) {
+      /* ./../lib/standard//collection//array.nit:243 */
       fra.me.REG[2] = fra.me.REG[0];
       REGB2 = REGB0;
+      /* ./../lib/standard//collection//array.nit:245 */
       REGB3 = TAG_Int(0);
+      /* ./../lib/standard//kernel.nit:213 */
       REGB3 = TAG_Bool(UNTAG_Int(REGB2)>=UNTAG_Int(REGB3));
-      /* ./../lib/standard//collection//array.nit:233 */
+      /* ./../lib/standard//collection//array.nit:245 */
       if (UNTAG_Bool(REGB3)) {
         REGB3 = TAG_Bool(ATTR_array___AbstractArrayRead____length(fra.me.REG[2])!=NIT_NULL);
         if (UNTAG_Bool(REGB3)) {
         } else {
-          fprintf(stderr, "Uninitialized attribute %s", "_length");
-          fprintf(stderr, " (%s:%d)\n", LOCATE_array, 233);
-          nit_exit(1);
+          nit_abort("Uninitialized attribute %s", "_length", LOCATE_array, 245);
         }
         REGB3 = ATTR_array___AbstractArrayRead____length(fra.me.REG[2]);
+        /* ./../lib/standard//kernel.nit:212 */
         REGB3 = TAG_Bool(UNTAG_Int(REGB2)<UNTAG_Int(REGB3));
-      /* ./../lib/standard//collection//array.nit:233 */
       } else {
+        /* ./../lib/standard//collection//array.nit:245 */
         REGB4 = TAG_Bool(false);
         REGB3 = REGB4;
       }
       if (UNTAG_Bool(REGB3)) {
       } else {
-        fprintf(stderr, "Assert %s  failed", "'index'");
-        fprintf(stderr, " (%s:%d)\n", LOCATE_array, 233);
-        nit_exit(1);
+        nit_abort("Assert %s  failed", "'index'", LOCATE_array, 245);
       }
+      /* ./../lib/standard//collection//array.nit:246 */
       fra.me.REG[2] = ATTR_array___Array____items(fra.me.REG[2]);
       REGB3 = TAG_Bool(fra.me.REG[2]==NIT_NULL);
-      /* ./../lib/standard//collection//array.nit:234 */
       if (UNTAG_Bool(REGB3)) {
-        fprintf(stderr, "Reciever is null");
-        fprintf(stderr, " (%s:%d)\n", LOCATE_array, 234);
-        nit_exit(1);
+        nit_abort("Reciever is null", NULL, LOCATE_array, 246);
       }
+      /* ./../lib/standard//collection//array.nit:654 */
       fra.me.REG[2] = ((Nit_NativeArray)fra.me.REG[2])->val[UNTAG_Int(REGB2)];
-      /* ./../lib/standard//collection//array.nit:234 */
+      /* ./../lib/standard//collection//array.nit:246 */
       goto label1;
       label1: while(0);
-      REGB2 = TAG_Bool(fra.me.REG[2]==NIT_NULL);
       /* ./../lib/standard//string.nit:545 */
+      REGB2 = TAG_Bool(fra.me.REG[2]==NIT_NULL);
       if (UNTAG_Bool(REGB2)) {
       } else {
         REGB3 = TAG_Bool(fra.me.REG[2]==NIT_NULL);
@@ -2701,25 +2791,25 @@ val_t string___Array___to_s(val_t p0){
       if (UNTAG_Bool(REGB2)) {
         REGB2 = TAG_Bool(fra.me.REG[2]==NIT_NULL);
         if (UNTAG_Bool(REGB2)) {
-          fprintf(stderr, "Reciever is null");
-          fprintf(stderr, " (%s:%d)\n", LOCATE_string, 545);
-          nit_exit(1);
+          nit_abort("Reciever is null", NULL, LOCATE_string, 545);
         }
         fra.me.REG[2] = CALL_string___Object___to_s(fra.me.REG[2])(fra.me.REG[2]);
         CALL_abstract_collection___Sequence___append(fra.me.REG[1])(fra.me.REG[1], fra.me.REG[2]);
       }
+      /* ./../lib/standard//string.nit:546 */
       REGB2 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:215 */
       REGB2 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB2));
+      /* ./../lib/standard//string.nit:546 */
       REGB0 = REGB2;
-    /* ./../lib/standard//string.nit:546 */
     } else {
       /* ./../lib/standard//string.nit:543 */
       goto label2;
     }
   }
   label2: while(0);
-  fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
   /* ./../lib/standard//string.nit:548 */
+  fra.me.REG[1] = CALL_string___Object___to_s(fra.me.REG[1])(fra.me.REG[1]);
   goto label3;
   label3: while(0);
   stack_frame_head = fra.me.prev;
@@ -2757,8 +2847,8 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
   fra.me.REG[0] = p0;
   fra.me.REG[1] = p1;
   fra.me.REG[2] = p2;
-  REGB0 = CALL_abstract_collection___Collection___is_empty(fra.me.REG[0])(fra.me.REG[0]);
   /* ./../lib/standard//string.nit:556 */
+  REGB0 = CALL_abstract_collection___Collection___is_empty(fra.me.REG[0])(fra.me.REG[0]);
   if (UNTAG_Bool(REGB0)) {
     if (!once_value_1) {
       fra.me.REG[3] = BOX_NativeString("");
@@ -2767,14 +2857,19 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
       once_value_1 = fra.me.REG[3];
       register_static_object(&once_value_1);
     } else fra.me.REG[3] = once_value_1;
+    fra.me.REG[3] = fra.me.REG[3];
     goto label2;
   }
+  /* ./../lib/standard//string.nit:558 */
   fra.me.REG[4] = NEW_Buffer_string___Buffer___init();
+  /* ./../lib/standard//string.nit:561 */
   fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:562 */
   fra.me.REG[5] = CALL_abstract_collection___MapIterator___key(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:563 */
   fra.me.REG[6] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
-  REGB0 = TAG_Bool(fra.me.REG[6]==NIT_NULL);
   /* ./../lib/standard//string.nit:564 */
+  REGB0 = TAG_Bool(fra.me.REG[6]==NIT_NULL);
   if (UNTAG_Bool(REGB0)) {
   } else {
     REGB1 = TAG_Bool(fra.me.REG[6]==NIT_NULL);
@@ -2797,9 +2892,10 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
       once_value_3 = fra.me.REG[8];
       register_static_object(&once_value_3);
     } else fra.me.REG[8] = once_value_3;
-    array___Array___add(fra.me.REG[7], fra.me.REG[8]);
+    fra.me.REG[8] = fra.me.REG[8];
+    CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
     fra.me.REG[8] = CALL_string___Object___to_s(fra.me.REG[5])(fra.me.REG[5]);
-    array___Array___add(fra.me.REG[7], fra.me.REG[8]);
+    CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
     if (!once_value_4) {
       fra.me.REG[8] = BOX_NativeString("");
       REGB0 = TAG_Int(0);
@@ -2807,8 +2903,9 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
       once_value_4 = fra.me.REG[8];
       register_static_object(&once_value_4);
     } else fra.me.REG[8] = once_value_4;
-    array___Array___add(fra.me.REG[7], fra.me.REG[8]);
-    array___Array___add(fra.me.REG[7], fra.me.REG[2]);
+    fra.me.REG[8] = fra.me.REG[8];
+    CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
+    CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[2]);
     if (!once_value_5) {
       fra.me.REG[8] = BOX_NativeString("");
       REGB0 = TAG_Int(0);
@@ -2816,9 +2913,10 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
       once_value_5 = fra.me.REG[8];
       register_static_object(&once_value_5);
     } else fra.me.REG[8] = once_value_5;
-    array___Array___add(fra.me.REG[7], fra.me.REG[8]);
+    fra.me.REG[8] = fra.me.REG[8];
+    CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
     fra.me.REG[8] = CALL_string___Object___to_s(fra.me.REG[6])(fra.me.REG[6]);
-    array___Array___add(fra.me.REG[7], fra.me.REG[8]);
+    CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
     if (!once_value_6) {
       fra.me.REG[8] = BOX_NativeString("");
       REGB0 = TAG_Int(0);
@@ -2826,7 +2924,8 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
       once_value_6 = fra.me.REG[8];
       register_static_object(&once_value_6);
     } else fra.me.REG[8] = once_value_6;
-    array___Array___add(fra.me.REG[7], fra.me.REG[8]);
+    fra.me.REG[8] = fra.me.REG[8];
+    CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
     fra.me.REG[7] = CALL_string___Object___to_s(fra.me.REG[7])(fra.me.REG[7]);
     CALL_abstract_collection___Sequence___append(fra.me.REG[4])(fra.me.REG[4], fra.me.REG[7]);
   }
@@ -2838,12 +2937,14 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
     if (UNTAG_Bool(REGB0)) {
       /* ./../lib/standard//string.nit:569 */
       CALL_abstract_collection___Sequence___append(fra.me.REG[4])(fra.me.REG[4], fra.me.REG[1]);
+      /* ./../lib/standard//string.nit:570 */
       fra.me.REG[7] = CALL_abstract_collection___MapIterator___key(fra.me.REG[0])(fra.me.REG[0]);
       fra.me.REG[5] = fra.me.REG[7];
+      /* ./../lib/standard//string.nit:571 */
       fra.me.REG[7] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
       fra.me.REG[6] = fra.me.REG[7];
-      REGB0 = TAG_Bool(fra.me.REG[6]==NIT_NULL);
       /* ./../lib/standard//string.nit:572 */
+      REGB0 = TAG_Bool(fra.me.REG[6]==NIT_NULL);
       if (UNTAG_Bool(REGB0)) {
       } else {
         REGB1 = TAG_Bool(fra.me.REG[6]==NIT_NULL);
@@ -2866,9 +2967,10 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
           once_value_7 = fra.me.REG[8];
           register_static_object(&once_value_7);
         } else fra.me.REG[8] = once_value_7;
-        array___Array___add(fra.me.REG[7], fra.me.REG[8]);
+        fra.me.REG[8] = fra.me.REG[8];
+        CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
         fra.me.REG[8] = CALL_string___Object___to_s(fra.me.REG[5])(fra.me.REG[5]);
-        array___Array___add(fra.me.REG[7], fra.me.REG[8]);
+        CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
         if (!once_value_8) {
           fra.me.REG[8] = BOX_NativeString("");
           REGB0 = TAG_Int(0);
@@ -2876,8 +2978,9 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
           once_value_8 = fra.me.REG[8];
           register_static_object(&once_value_8);
         } else fra.me.REG[8] = once_value_8;
-        array___Array___add(fra.me.REG[7], fra.me.REG[8]);
-        array___Array___add(fra.me.REG[7], fra.me.REG[2]);
+        fra.me.REG[8] = fra.me.REG[8];
+        CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
+        CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[2]);
         if (!once_value_9) {
           fra.me.REG[8] = BOX_NativeString("");
           REGB0 = TAG_Int(0);
@@ -2885,9 +2988,10 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
           once_value_9 = fra.me.REG[8];
           register_static_object(&once_value_9);
         } else fra.me.REG[8] = once_value_9;
-        array___Array___add(fra.me.REG[7], fra.me.REG[8]);
+        fra.me.REG[8] = fra.me.REG[8];
+        CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
         fra.me.REG[8] = CALL_string___Object___to_s(fra.me.REG[6])(fra.me.REG[6]);
-        array___Array___add(fra.me.REG[7], fra.me.REG[8]);
+        CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
         if (!once_value_10) {
           fra.me.REG[8] = BOX_NativeString("");
           REGB0 = TAG_Int(0);
@@ -2895,7 +2999,8 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
           once_value_10 = fra.me.REG[8];
           register_static_object(&once_value_10);
         } else fra.me.REG[8] = once_value_10;
-        array___Array___add(fra.me.REG[7], fra.me.REG[8]);
+        fra.me.REG[8] = fra.me.REG[8];
+        CALL_abstract_collection___SimpleCollection___add(fra.me.REG[7])(fra.me.REG[7], fra.me.REG[8]);
         fra.me.REG[7] = CALL_string___Object___to_s(fra.me.REG[7])(fra.me.REG[7]);
         CALL_abstract_collection___Sequence___append(fra.me.REG[4])(fra.me.REG[4], fra.me.REG[7]);
       }
@@ -2907,9 +3012,9 @@ val_t string___Map___map_join(val_t p0, val_t p1, val_t p2){
     }
   }
   label11: while(0);
+  /* ./../lib/standard//string.nit:575 */
   fra.me.REG[4] = CALL_string___Object___to_s(fra.me.REG[4])(fra.me.REG[4]);
   fra.me.REG[3] = fra.me.REG[4];
-  /* ./../lib/standard//string.nit:575 */
   goto label2;
   label2: while(0);
   stack_frame_head = fra.me.prev;
@@ -2928,8 +3033,8 @@ val_t string___NativeString_____bra(val_t p0, val_t p1){
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
   REGB0 = p1;
-  REGB0 = TAG_Char(UNBOX_NativeString(fra.me.REG[0])[UNTAG_Int(REGB0)]);
   /* ./../lib/standard//string.nit:585 */
+  REGB0 = TAG_Char(UNBOX_NativeString(fra.me.REG[0])[UNTAG_Int(REGB0)]);
   stack_frame_head = fra.me.prev;
   return REGB0;
 }
@@ -2992,25 +3097,29 @@ val_t string___NativeString___cstring_length(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:592 */
   REGB0 = TAG_Int(0);
   /* ./../lib/standard//string.nit:593 */
   while(1) {
+    /* ./../lib/standard//string.nit:585 */
     REGB1 = TAG_Char(UNBOX_NativeString(fra.me.REG[0])[UNTAG_Int(REGB0)]);
+    /* ./../lib/standard//string.nit:593 */
     REGB2 = TAG_Char('\0');
     REGB3 = TAG_Bool(IS_EQUAL_OO(REGB1,REGB2));
-    /* ./../lib/standard//string.nit:593 */
     if (UNTAG_Bool(REGB3)) {
     } else {
+      /* ./../lib/standard//kernel.nit:347 */
       REGB2 = TAG_Bool((REGB1)==(REGB2));
+      /* ./../lib/standard//string.nit:593 */
       REGB3 = REGB2;
-    /* ./../lib/standard//string.nit:593 */
     }
     REGB3 = TAG_Bool(!UNTAG_Bool(REGB3));
     if (UNTAG_Bool(REGB3)) {
       REGB3 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:215 */
       REGB3 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB3));
+      /* ./../lib/standard//string.nit:593 */
       REGB0 = REGB3;
-    /* ./../lib/standard//string.nit:593 */
     } else {
       goto label1;
     }
@@ -3034,8 +3143,8 @@ val_t string___NativeString___atoi(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
-  REGB0 = TAG_Int(atoi(UNBOX_NativeString(fra.me.REG[0])));
   /* ./../lib/standard//string.nit:596 */
+  REGB0 = TAG_Int(atoi(UNBOX_NativeString(fra.me.REG[0])));
   stack_frame_head = fra.me.prev;
   return REGB0;
 }
@@ -3065,9 +3174,10 @@ val_t string___StringCapable___calloc_string(val_t p0, val_t p1){
   fra.me.has_broke = 0;
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
   REGB0 = p1;
-  fra.me.REG[0] = BOX_NativeString((char*)raw_alloc((UNTAG_Int(REGB0) * sizeof(char))));
   /* ./../lib/standard//string.nit:601 */
+  fra.me.REG[0] = BOX_NativeString((char*)raw_alloc((UNTAG_Int(REGB0) * sizeof(char))));
   stack_frame_head = fra.me.prev;
   return fra.me.REG[0];
 }
@@ -3100,9 +3210,9 @@ val_t string___Sys___args(val_t p0){
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[1] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:609 */
   fra.me.REG[1] = ATTR_string___Sys____args_cache(fra.me.REG[0]);
   REGB0 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
-  /* ./../lib/standard//string.nit:609 */
   if (UNTAG_Bool(REGB0)) {
   } else {
     REGB1 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
@@ -3117,14 +3227,12 @@ val_t string___Sys___args(val_t p0){
   if (UNTAG_Bool(REGB0)) {
     CALL_string___Sys___init_args(fra.me.REG[0])(fra.me.REG[0]);
   }
+  /* ./../lib/standard//string.nit:610 */
   fra.me.REG[0] = ATTR_string___Sys____args_cache(fra.me.REG[0]);
   REGB0 = TAG_Bool(fra.me.REG[0]!=NIT_NULL);
-  /* ./../lib/standard//string.nit:610 */
   if (UNTAG_Bool(REGB0)) {
   } else {
-    fprintf(stderr, "Cast failed");
-    fprintf(stderr, " (%s:%d)\n", LOCATE_string, 610);
-    nit_exit(1);
+    nit_abort("Cast failed", NULL, LOCATE_string, 610);
   }
   goto label1;
   label1: while(0);
@@ -3143,10 +3251,10 @@ val_t string___Sys___program_name(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:616 */
   REGB0 = TAG_Int(0);
   fra.me.REG[0] = CALL_string___Sys___native_argv(fra.me.REG[0])(fra.me.REG[0], REGB0);
   fra.me.REG[0] = NEW_String_string___String___from_cstring(fra.me.REG[0]);
-  /* ./../lib/standard//string.nit:616 */
   goto label1;
   label1: while(0);
   stack_frame_head = fra.me.prev;
@@ -3168,25 +3276,33 @@ void string___Sys___init_args(val_t p0){
   fra.me.REG[1] = NIT_NULL;
   fra.me.REG[2] = NIT_NULL;
   fra.me.REG[0] = p0;
+  /* ./../lib/standard//string.nit:622 */
   REGB0 = CALL_string___Sys___native_argc(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//string.nit:623 */
   REGB1 = TAG_Int(0);
   fra.me.REG[1] = NEW_Array_array___Array___with_capacity(REGB1);
+  /* ./../lib/standard//string.nit:624 */
   REGB1 = TAG_Int(1);
   /* ./../lib/standard//string.nit:625 */
   while(1) {
+    /* ./../lib/standard//kernel.nit:212 */
     REGB2 = TAG_Bool(UNTAG_Int(REGB1)<UNTAG_Int(REGB0));
     /* ./../lib/standard//string.nit:625 */
     if (UNTAG_Bool(REGB2)) {
+      /* ./../lib/standard//string.nit:626 */
       REGB2 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:217 */
       REGB2 = TAG_Int(UNTAG_Int(REGB1)-UNTAG_Int(REGB2));
+      /* ./../lib/standard//string.nit:626 */
       fra.me.REG[2] = CALL_string___Sys___native_argv(fra.me.REG[0])(fra.me.REG[0], REGB1);
       fra.me.REG[2] = NEW_String_string___String___from_cstring(fra.me.REG[2]);
-      /* ./../lib/standard//string.nit:626 */
       CALL_abstract_collection___Map_____braeq(fra.me.REG[1])(fra.me.REG[1], REGB2, fra.me.REG[2]);
+      /* ./../lib/standard//string.nit:627 */
       REGB2 = TAG_Int(1);
+      /* ./../lib/standard//kernel.nit:215 */
       REGB2 = TAG_Int(UNTAG_Int(REGB1)+UNTAG_Int(REGB2));
+      /* ./../lib/standard//string.nit:627 */
       REGB1 = REGB2;
-    /* ./../lib/standard//string.nit:627 */
     } else {
       /* ./../lib/standard//string.nit:625 */
       goto label1;
@@ -3210,8 +3326,8 @@ val_t string___Sys___native_argc(val_t p0){
   fra.me.REG_size = 1;
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
-  REGB0 = TAG_Int(kernel_Sys_Sys_native_argc_0(fra.me.REG[0]));
   /* ./../lib/standard//string.nit:632 */
+  REGB0 = TAG_Int(kernel_Sys_Sys_native_argc_0(fra.me.REG[0]));
   stack_frame_head = fra.me.prev;
   return REGB0;
 }
@@ -3228,8 +3344,8 @@ val_t string___Sys___native_argv(val_t p0, val_t p1){
   fra.me.REG[0] = NIT_NULL;
   fra.me.REG[0] = p0;
   REGB0 = p1;
-  fra.me.REG[0] = BOX_NativeString(kernel_Sys_Sys_native_argv_1(fra.me.REG[0], UNTAG_Int(REGB0)));
   /* ./../lib/standard//string.nit:634 */
+  fra.me.REG[0] = BOX_NativeString(kernel_Sys_Sys_native_argv_1(fra.me.REG[0], UNTAG_Int(REGB0)));
   stack_frame_head = fra.me.prev;
   return fra.me.REG[0];
 }