Merge branch 'alexis/various-fixes' into wip
[nit.git] / c_src / abstract_collection._sep.c
index 9b1ec0b..b3774b9 100644 (file)
 /* This C file is generated by NIT to compile module abstract_collection. */
 #include "abstract_collection._sep.h"
-val_t abstract_collection___Collection___iterator(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 42, LOCATE_abstract_collection___Collection___iterator};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___Collection___iterator(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_abstract_collection;
+  fra.me.line = 42;
+  fra.me.meth = LOCATE_abstract_collection___Collection___iterator;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:42 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 42);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___Collection___is_empty(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 45, LOCATE_abstract_collection___Collection___is_empty};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___Collection___is_empty(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_abstract_collection;
+  fra.me.line = 45;
+  fra.me.meth = LOCATE_abstract_collection___Collection___is_empty;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:45 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 45);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___Collection___length(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 48, LOCATE_abstract_collection___Collection___length};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___Collection___length(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_abstract_collection;
+  fra.me.line = 48;
+  fra.me.meth = LOCATE_abstract_collection___Collection___length;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:48 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 48);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___Collection___has(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 51, LOCATE_abstract_collection___Collection___has};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___Collection___has(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 51;
+  fra.me.meth = LOCATE_abstract_collection___Collection___has;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:51 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 51);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___Collection___has_only(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 55, LOCATE_abstract_collection___Collection___has_only};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___Collection___has_only(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 55;
+  fra.me.meth = LOCATE_abstract_collection___Collection___has_only;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:55 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 55);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___Collection___count(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 60, LOCATE_abstract_collection___Collection___count};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___Collection___count(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 60;
+  fra.me.meth = LOCATE_abstract_collection___Collection___count;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:60 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 60);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___Collection___first(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 64, LOCATE_abstract_collection___Collection___first};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___Collection___first(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_abstract_collection;
+  fra.me.line = 64;
+  fra.me.meth = LOCATE_abstract_collection___Collection___first;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:64 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 64);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___NaiveCollection___is_empty(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 72, LOCATE_abstract_collection___NaiveCollection___is_empty};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Collection___length(variable[0])(variable[0]) /*NaiveCollection::length*/;
-  /* Register variable[2]: Result */
-  variable[2] = TAG_Bool((variable[2])==( TAG_Int(0)));
-  variable[1] = variable[2];
-  goto return_label0;
-  return_label0: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-val_t abstract_collection___NaiveCollection___length(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 74, LOCATE_abstract_collection___NaiveCollection___length};
-  val_t variable[6];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Local variable */
-  variable[2] =  TAG_Int(0);
-  /* Register variable[3]: For iterator */
-  variable[3] = CALL_abstract_collection___Collection___iterator(variable[0])(variable[0]) /*Collection::iterator*/;
-  while (true) { /*for*/
-    /* Register variable[4]: For 'is_ok' result */
-    variable[4] = CALL_abstract_collection___Iterator___is_ok(variable[3])(variable[3]) /*Iterator::is_ok*/;
-    if (!UNTAG_Bool(variable[4])) break; /*for*/
-    variable[4] = CALL_abstract_collection___Iterator___item(variable[3])(variable[3]) /*Iterator::item*/ /* Ensure var: For item*/;
-    /* Register variable[5]: Local variable */
-    variable[5] = variable[4];
-    variable[2] = TAG_Int(UNTAG_Int(variable[2])+UNTAG_Int( variable[2] /*nb*/)) /*nb*/;
-    continue_2: while(0);
-    CALL_abstract_collection___Iterator___next(variable[3])(variable[3]) /*Iterator::next*/;
+val_t abstract_collection___NaiveCollection___is_empty(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_abstract_collection;
+  fra.me.line = 72;
+  fra.me.meth = LOCATE_abstract_collection___NaiveCollection___is_empty;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  REGB0 = CALL_abstract_collection___Collection___length(fra.me.REG[0])(fra.me.REG[0]);
+  REGB1 = TAG_Int(0);
+  REGB2 = TAG_Bool(IS_EQUAL_OO(REGB0,REGB1));
+  /* ./../lib/standard//collection//abstract_collection.nit:72 */
+  if (UNTAG_Bool(REGB2)) {
+  } else {
+    REGB1 = TAG_Bool((REGB0)==(REGB1));
+    REGB2 = REGB1;
+  /* ./../lib/standard//collection//abstract_collection.nit:72 */
   }
-  break_2: while(0);
-  variable[1] =  variable[2] /*nb*/;
-  goto return_label1;
-  return_label1: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-val_t abstract_collection___NaiveCollection___has(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 81, LOCATE_abstract_collection___NaiveCollection___has};
-  val_t variable[7];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: For iterator */
-  variable[3] = CALL_abstract_collection___Collection___iterator(variable[0])(variable[0]) /*Collection::iterator*/;
-  while (true) { /*for*/
-    /* Register variable[4]: For 'is_ok' result */
-    variable[4] = CALL_abstract_collection___Iterator___is_ok(variable[3])(variable[3]) /*Iterator::is_ok*/;
-    if (!UNTAG_Bool(variable[4])) break; /*for*/
-    variable[4] = CALL_abstract_collection___Iterator___item(variable[3])(variable[3]) /*Iterator::item*/ /* Ensure var: For item*/;
-    /* Register variable[5]: Local variable */
-    variable[5] = variable[4];
-    /* Register variable[6]: Result */
-    variable[6] = TAG_Bool(( variable[5] /*i*/ ==  variable[1] /*item*/) || (( variable[5] /*i*/ != NIT_NULL) && ((CALL_kernel___Object_____eqeq( variable[5] /*i*/)==kernel___Object_____eqeq)?(IS_EQUAL_NN( variable[5] /*i*/, variable[1] /*item*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq( variable[5] /*i*/)( variable[5] /*i*/,  variable[1] /*item*/) /*Object::==*/)))));
-    if (UNTAG_Bool(variable[6])) { /*if*/
-      variable[2] =  TAG_Bool(true);
-      goto return_label3;
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB2;
+}
+val_t abstract_collection___NaiveCollection___length(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_abstract_collection;
+  fra.me.line = 74;
+  fra.me.meth = LOCATE_abstract_collection___NaiveCollection___length;
+  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 = TAG_Int(0);
+  fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:77 */
+  while(1) {
+    REGB1 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[0])(fra.me.REG[0]);
+    if (UNTAG_Bool(REGB1)) {
+      fra.me.REG[1] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
+      REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB0));
+      REGB0 = REGB1;
+    /* ./../lib/standard//collection//abstract_collection.nit:77 */
+    } else {
+      goto label1;
     }
-    continue_4: while(0);
-    CALL_abstract_collection___Iterator___next(variable[3])(variable[3]) /*Iterator::next*/;
+    CALL_abstract_collection___Iterator___next(fra.me.REG[0])(fra.me.REG[0]);
   }
-  break_4: while(0);
-  variable[2] =  TAG_Bool(false);
-  goto return_label3;
-  return_label3: while(false);
-  tracehead = trace.prev;
-  return variable[2];
-}
-val_t abstract_collection___NaiveCollection___has_only(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 87, LOCATE_abstract_collection___NaiveCollection___has_only};
-  val_t variable[7];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: For iterator */
-  variable[3] = CALL_abstract_collection___Collection___iterator(variable[0])(variable[0]) /*Collection::iterator*/;
-  while (true) { /*for*/
-    /* Register variable[4]: For 'is_ok' result */
-    variable[4] = CALL_abstract_collection___Iterator___is_ok(variable[3])(variable[3]) /*Iterator::is_ok*/;
-    if (!UNTAG_Bool(variable[4])) break; /*for*/
-    variable[4] = CALL_abstract_collection___Iterator___item(variable[3])(variable[3]) /*Iterator::item*/ /* Ensure var: For item*/;
-    /* Register variable[5]: Local variable */
-    variable[5] = variable[4];
-    /* Register variable[6]: Result */
-    variable[6] = TAG_Bool(!UNTAG_Bool(TAG_Bool(( variable[5] /*i*/ ==  variable[1] /*item*/) || (( variable[5] /*i*/ != NIT_NULL) && ((CALL_kernel___Object_____eqeq( variable[5] /*i*/)==kernel___Object_____eqeq)?(IS_EQUAL_NN( variable[5] /*i*/, variable[1] /*item*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq( variable[5] /*i*/)( variable[5] /*i*/,  variable[1] /*item*/) /*Object::==*/)))))));
-    if (UNTAG_Bool(variable[6])) { /*if*/
-      variable[2] =  TAG_Bool(false);
-      goto return_label5;
+  label1: while(0);
+  /* ./../lib/standard//collection//abstract_collection.nit:78 */
+  goto label2;
+  label2: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___NaiveCollection___has(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_abstract_collection;
+  fra.me.line = 81;
+  fra.me.meth = LOCATE_abstract_collection___NaiveCollection___has;
+  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;
+  fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:83 */
+  while(1) {
+    REGB0 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[0])(fra.me.REG[0]);
+    if (UNTAG_Bool(REGB0)) {
+      fra.me.REG[2] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
+      REGB0 = TAG_Bool(IS_EQUAL_NN(fra.me.REG[2],fra.me.REG[1]));
+      if (UNTAG_Bool(REGB0)) {
+      } 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], fra.me.REG[1]);
+          REGB0 = REGB1;
+        }
+      }
+      if (UNTAG_Bool(REGB0)) {
+        REGB0 = TAG_Bool(true);
+        goto label1;
+      }
+    } else {
+      goto label2;
     }
-    continue_6: while(0);
-    CALL_abstract_collection___Iterator___next(variable[3])(variable[3]) /*Iterator::next*/;
+    CALL_abstract_collection___Iterator___next(fra.me.REG[0])(fra.me.REG[0]);
   }
-  break_6: while(0);
-  variable[2] =  TAG_Bool(true);
-  goto return_label5;
-  return_label5: while(false);
-  tracehead = trace.prev;
-  return variable[2];
-}
-val_t abstract_collection___NaiveCollection___count(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 93, LOCATE_abstract_collection___NaiveCollection___count};
-  val_t variable[8];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Local variable */
-  variable[3] =  TAG_Int(0);
-  /* Register variable[4]: For iterator */
-  variable[4] = CALL_abstract_collection___Collection___iterator(variable[0])(variable[0]) /*Collection::iterator*/;
-  while (true) { /*for*/
-    /* Register variable[5]: For 'is_ok' result */
-    variable[5] = CALL_abstract_collection___Iterator___is_ok(variable[4])(variable[4]) /*Iterator::is_ok*/;
-    if (!UNTAG_Bool(variable[5])) break; /*for*/
-    variable[5] = CALL_abstract_collection___Iterator___item(variable[4])(variable[4]) /*Iterator::item*/ /* Ensure var: For item*/;
-    /* Register variable[6]: Local variable */
-    variable[6] = variable[5];
-    /* Register variable[7]: Result */
-    variable[7] = TAG_Bool(( variable[6] /*i*/ ==  variable[1] /*item*/) || (( variable[6] /*i*/ != NIT_NULL) && ((CALL_kernel___Object_____eqeq( variable[6] /*i*/)==kernel___Object_____eqeq)?(IS_EQUAL_NN( variable[6] /*i*/, variable[1] /*item*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq( variable[6] /*i*/)( variable[6] /*i*/,  variable[1] /*item*/) /*Object::==*/)))));
-    if (UNTAG_Bool(variable[7])) { /*if*/
-      variable[3] = TAG_Int(UNTAG_Int(variable[3])+UNTAG_Int( TAG_Int(1))) /*nb*/;
+  label2: while(0);
+  REGB1 = TAG_Bool(false);
+  REGB0 = REGB1;
+  /* ./../lib/standard//collection//abstract_collection.nit:84 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___NaiveCollection___has_only(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_abstract_collection;
+  fra.me.line = 87;
+  fra.me.meth = LOCATE_abstract_collection___NaiveCollection___has_only;
+  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;
+  fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:89 */
+  while(1) {
+    REGB0 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[0])(fra.me.REG[0]);
+    if (UNTAG_Bool(REGB0)) {
+      fra.me.REG[2] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
+      REGB0 = TAG_Bool(IS_EQUAL_NN(fra.me.REG[2],fra.me.REG[1]));
+      if (UNTAG_Bool(REGB0)) {
+      } 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], fra.me.REG[1]);
+          REGB0 = REGB1;
+        }
+      }
+      REGB0 = TAG_Bool(!UNTAG_Bool(REGB0));
+      if (UNTAG_Bool(REGB0)) {
+        REGB0 = TAG_Bool(false);
+        goto label1;
+      }
+    } else {
+      goto label2;
     }
-    continue_8: while(0);
-    CALL_abstract_collection___Iterator___next(variable[4])(variable[4]) /*Iterator::next*/;
+    CALL_abstract_collection___Iterator___next(fra.me.REG[0])(fra.me.REG[0]);
   }
-  break_8: while(0);
-  variable[2] =  variable[3] /*nb*/;
-  goto return_label7;
-  return_label7: while(false);
-  tracehead = trace.prev;
-  return variable[2];
-}
-val_t abstract_collection___NaiveCollection___first(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 100, LOCATE_abstract_collection___NaiveCollection___first};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Collection___length(variable[0])(variable[0]) /*NaiveCollection::length*/;
-  /* Register variable[2]: Result */
-  variable[2] = TAG_Bool(UNTAG_Int(variable[2])>UNTAG_Int( TAG_Int(0)));
-  if (!UNTAG_Bool(variable[2])) { fprintf(stderr, "Assert%s failed", ""); fprintf(stderr, " in %s (%s:%d)\n", LOCATE_abstract_collection___NaiveCollection___first, LOCATE_abstract_collection, 102); nit_exit(1);}
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Collection___iterator(variable[0])(variable[0]) /*Collection::iterator*/;
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Iterator___item(variable[2])(variable[2]) /*Iterator::item*/;
-  variable[1] = variable[2];
-  goto return_label9;
-  return_label9: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-val_t abstract_collection___Iterator___item(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 110, LOCATE_abstract_collection___Iterator___item};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+  label2: while(0);
+  REGB1 = TAG_Bool(true);
+  REGB0 = REGB1;
+  /* ./../lib/standard//collection//abstract_collection.nit:90 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___NaiveCollection___count(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 tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_abstract_collection;
+  fra.me.line = 93;
+  fra.me.meth = LOCATE_abstract_collection___NaiveCollection___count;
+  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_Int(0);
+  fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:96 */
+  while(1) {
+    REGB1 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[0])(fra.me.REG[0]);
+    if (UNTAG_Bool(REGB1)) {
+      fra.me.REG[2] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
+      REGB1 = TAG_Bool(IS_EQUAL_NN(fra.me.REG[2],fra.me.REG[1]));
+      if (UNTAG_Bool(REGB1)) {
+      } else {
+        REGB2 = TAG_Bool(fra.me.REG[2]==NIT_NULL);
+        if (UNTAG_Bool(REGB2)) {
+          REGB2 = TAG_Bool(false);
+          REGB1 = REGB2;
+        } else {
+          REGB2 = CALL_kernel___Object_____eqeq(fra.me.REG[2])(fra.me.REG[2], fra.me.REG[1]);
+          REGB1 = REGB2;
+        }
+      }
+      if (UNTAG_Bool(REGB1)) {
+        REGB1 = TAG_Int(1);
+        REGB1 = TAG_Int(UNTAG_Int(REGB0)+UNTAG_Int(REGB1));
+        REGB0 = REGB1;
+      /* ./../lib/standard//collection//abstract_collection.nit:96 */
+      }
+    } else {
+      goto label1;
+    }
+    CALL_abstract_collection___Iterator___next(fra.me.REG[0])(fra.me.REG[0]);
+  }
+  label1: while(0);
+  /* ./../lib/standard//collection//abstract_collection.nit:97 */
+  goto label2;
+  label2: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___NaiveCollection___first(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_abstract_collection;
+  fra.me.line = 100;
+  fra.me.meth = LOCATE_abstract_collection___NaiveCollection___first;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  REGB0 = CALL_abstract_collection___Collection___length(fra.me.REG[0])(fra.me.REG[0]);
+  REGB1 = TAG_Int(0);
+  REGB1 = TAG_Bool(UNTAG_Int(REGB0)>UNTAG_Int(REGB1));
+  /* ./../lib/standard//collection//abstract_collection.nit:102 */
+  if (UNTAG_Bool(REGB1)) {
+  } else {
+    fprintf(stderr, "Assert failed");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 102);
+    nit_exit(1);
+  }
+  fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
+  fra.me.REG[0] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:103 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+val_t abstract_collection___Iterator___item(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_abstract_collection;
+  fra.me.line = 110;
+  fra.me.meth = LOCATE_abstract_collection___Iterator___item;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:110 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 110);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-void abstract_collection___Iterator___next(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 114, LOCATE_abstract_collection___Iterator___next};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+void abstract_collection___Iterator___next(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_abstract_collection;
+  fra.me.line = 114;
+  fra.me.meth = LOCATE_abstract_collection___Iterator___next;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:114 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 114);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return;
 }
-val_t abstract_collection___Iterator___is_ok(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 118, LOCATE_abstract_collection___Iterator___is_ok};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___Iterator___is_ok(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_abstract_collection;
+  fra.me.line = 118;
+  fra.me.meth = LOCATE_abstract_collection___Iterator___is_ok;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:118 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 118);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___Container___iterator(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 145, LOCATE_abstract_collection___Container___iterator};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = NEW_ContainerIterator_abstract_collection___ContainerIterator___init(variable[0]) /*new ContainerIterator[E]*/;
-  variable[1] = variable[2];
-  goto return_label10;
-  return_label10: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-val_t abstract_collection___Container___is_empty(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 128, LOCATE_abstract_collection___Container___is_empty};
-  val_t variable[2];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  variable[1] =  TAG_Bool(false);
-  goto return_label11;
-  return_label11: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-val_t abstract_collection___Container___length(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 130, LOCATE_abstract_collection___Container___length};
-  val_t variable[2];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  variable[1] =  TAG_Int(1);
-  goto return_label12;
-  return_label12: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-val_t abstract_collection___Container___has(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 132, LOCATE_abstract_collection___Container___has};
-  val_t variable[4];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Result */
-  variable[3] = ATTR_abstract_collection___Container____item(variable[0]) /*Container::_item*/;
-  /* Register variable[3]: Result */
-  variable[3] = TAG_Bool((variable[3] ==  variable[1] /*an_item*/) || ((variable[3] != NIT_NULL) && ((CALL_kernel___Object_____eqeq(variable[3])==kernel___Object_____eqeq)?(IS_EQUAL_NN(variable[3], variable[1] /*an_item*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq(variable[3])(variable[3],  variable[1] /*an_item*/) /*Object::==*/)))));
-  variable[2] = variable[3];
-  goto return_label13;
-  return_label13: while(false);
-  tracehead = trace.prev;
-  return variable[2];
-}
-val_t abstract_collection___Container___has_only(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 134, LOCATE_abstract_collection___Container___has_only};
-  val_t variable[4];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Result */
-  variable[3] = ATTR_abstract_collection___Container____item(variable[0]) /*Container::_item*/;
-  /* Register variable[3]: Result */
-  variable[3] = TAG_Bool((variable[3] ==  variable[1] /*an_item*/) || ((variable[3] != NIT_NULL) && ((CALL_kernel___Object_____eqeq(variable[3])==kernel___Object_____eqeq)?(IS_EQUAL_NN(variable[3], variable[1] /*an_item*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq(variable[3])(variable[3],  variable[1] /*an_item*/) /*Object::==*/)))));
-  variable[2] = variable[3];
-  goto return_label14;
-  return_label14: while(false);
-  tracehead = trace.prev;
-  return variable[2];
-}
-val_t abstract_collection___Container___count(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 136, LOCATE_abstract_collection___Container___count};
-  val_t variable[4];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Result */
-  variable[3] = ATTR_abstract_collection___Container____item(variable[0]) /*Container::_item*/;
-  /* Register variable[3]: Result */
-  variable[3] = TAG_Bool((variable[3] ==  variable[1] /*an_item*/) || ((variable[3] != NIT_NULL) && ((CALL_kernel___Object_____eqeq(variable[3])==kernel___Object_____eqeq)?(IS_EQUAL_NN(variable[3], variable[1] /*an_item*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq(variable[3])(variable[3],  variable[1] /*an_item*/) /*Object::==*/)))));
-  if (UNTAG_Bool(variable[3])) { /*if*/
-    variable[2] =  TAG_Int(1);
-    goto return_label15;
-  } else { /*if*/
-    variable[2] =  TAG_Int(0);
-    goto return_label15;
+val_t abstract_collection___Container___iterator(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_abstract_collection;
+  fra.me.line = 145;
+  fra.me.meth = LOCATE_abstract_collection___Container___iterator;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  fra.me.REG[0] = NEW_ContainerIterator_abstract_collection___ContainerIterator___init(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:145 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+val_t abstract_collection___Container___is_empty(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_abstract_collection;
+  fra.me.line = 128;
+  fra.me.meth = LOCATE_abstract_collection___Container___is_empty;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  REGB0 = TAG_Bool(false);
+  /* ./../lib/standard//collection//abstract_collection.nit:128 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___Container___length(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_abstract_collection;
+  fra.me.line = 130;
+  fra.me.meth = LOCATE_abstract_collection___Container___length;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  REGB0 = TAG_Int(1);
+  /* ./../lib/standard//collection//abstract_collection.nit:130 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___Container___has(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_abstract_collection;
+  fra.me.line = 132;
+  fra.me.meth = LOCATE_abstract_collection___Container___has;
+  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;
+  fra.me.REG[0] = ATTR_abstract_collection___Container____item(fra.me.REG[0]);
+  REGB0 = TAG_Bool(IS_EQUAL_NN(fra.me.REG[0],fra.me.REG[1]));
+  /* ./../lib/standard//collection//abstract_collection.nit:132 */
+  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 = CALL_kernel___Object_____eqeq(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+      REGB0 = REGB1;
+    }
+  }
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___Container___has_only(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_abstract_collection;
+  fra.me.line = 134;
+  fra.me.meth = LOCATE_abstract_collection___Container___has_only;
+  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;
+  fra.me.REG[0] = ATTR_abstract_collection___Container____item(fra.me.REG[0]);
+  REGB0 = TAG_Bool(IS_EQUAL_NN(fra.me.REG[0],fra.me.REG[1]));
+  /* ./../lib/standard//collection//abstract_collection.nit:134 */
+  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 = CALL_kernel___Object_____eqeq(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+      REGB0 = REGB1;
+    }
+  }
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___Container___count(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_abstract_collection;
+  fra.me.line = 136;
+  fra.me.meth = LOCATE_abstract_collection___Container___count;
+  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;
+  fra.me.REG[0] = ATTR_abstract_collection___Container____item(fra.me.REG[0]);
+  REGB0 = TAG_Bool(IS_EQUAL_NN(fra.me.REG[0],fra.me.REG[1]));
+  /* ./../lib/standard//collection//abstract_collection.nit:138 */
+  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 = CALL_kernel___Object_____eqeq(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+      REGB0 = REGB1;
+    }
+  }
+  if (UNTAG_Bool(REGB0)) {
+    REGB0 = TAG_Int(1);
+    /* ./../lib/standard//collection//abstract_collection.nit:139 */
+    goto label1;
+  } else {
+    REGB1 = TAG_Int(0);
+    REGB0 = REGB1;
+    /* ./../lib/standard//collection//abstract_collection.nit:141 */
+    goto label1;
   }
-  return_label15: while(false);
-  tracehead = trace.prev;
-  return variable[2];
-}
-val_t abstract_collection___Container___first(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 126, LOCATE_abstract_collection___Container___first};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = ATTR_abstract_collection___Container____item(variable[0]) /*Container::_item*/;
-  variable[1] = variable[2];
-  goto return_label16;
-  return_label16: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-void abstract_collection___Container___init(val_t  self, val_t  param0, int* init_table) {
-  struct trace_t trace = {NULL, NULL, 147, LOCATE_abstract_collection___Container___init};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  if (init_table[VAL2OBJ(variable[0])->vft[INIT_TABLE_POS_Container].i]) return;
-  /* Register variable[2]: Method return value and escape marker */
-  ATTR_abstract_collection___Container____item(variable[0]) /*Container::_item*/ =  variable[1] /*e*/;
-  return_label17: while(false);
-  init_table[VAL2OBJ(variable[0])->vft[INIT_TABLE_POS_Container].i] = 1;
-  tracehead = trace.prev;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___Container___first(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_abstract_collection;
+  fra.me.line = 126;
+  fra.me.meth = LOCATE_abstract_collection___Container___first;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  fra.me.REG[0] = ATTR_abstract_collection___Container____item(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:126 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+void abstract_collection___Container___init(val_t p0, val_t p1, int* init_table){
+  int itpos0 = VAL2OBJ(p0)->vft[INIT_TABLE_POS_Container].i;
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+  val_t tmp;
+  if (init_table[itpos0]) return;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_abstract_collection;
+  fra.me.line = 147;
+  fra.me.meth = LOCATE_abstract_collection___Container___init;
+  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//collection//abstract_collection.nit:148 */
+  ATTR_abstract_collection___Container____item(fra.me.REG[0]) = fra.me.REG[1];
+  stack_frame_head = fra.me.prev;
+  init_table[itpos0] = 1;
   return;
 }
-val_t abstract_collection___Container___item(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 150, LOCATE_abstract_collection___Container___item};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  tracehead = trace.prev;
-  return ATTR_abstract_collection___Container____item( self) /*Container::_item*/;
-}
-void abstract_collection___Container___item__eq(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 150, LOCATE_abstract_collection___Container___item__eq};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  ATTR_abstract_collection___Container____item( self) /*Container::_item*/ =  param0;
-  tracehead = trace.prev;
+val_t abstract_collection___Container___item(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_abstract_collection;
+  fra.me.line = 150;
+  fra.me.meth = LOCATE_abstract_collection___Container___item;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  fra.me.REG[0] = ATTR_abstract_collection___Container____item(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:150 */
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+void abstract_collection___Container___item__eq(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 150;
+  fra.me.meth = LOCATE_abstract_collection___Container___item__eq;
+  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//collection//abstract_collection.nit:150 */
+  ATTR_abstract_collection___Container____item(fra.me.REG[0]) = fra.me.REG[1];
+  stack_frame_head = fra.me.prev;
   return;
 }
-val_t abstract_collection___ContainerIterator___item(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 157, LOCATE_abstract_collection___ContainerIterator___item};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = ATTR_abstract_collection___ContainerIterator____container(variable[0]) /*ContainerIterator::_container*/;
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Container___item(variable[2])(variable[2]) /*Container::item*/;
-  variable[1] = variable[2];
-  goto return_label18;
-  return_label18: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-void abstract_collection___ContainerIterator___next(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 159, LOCATE_abstract_collection___ContainerIterator___next};
-  val_t variable[2];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  ATTR_abstract_collection___ContainerIterator____is_ok(variable[0]) /*ContainerIterator::_is_ok*/ =  TAG_Bool(false);
-  return_label19: while(false);
-  tracehead = trace.prev;
+val_t abstract_collection___ContainerIterator___item(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_abstract_collection;
+  fra.me.line = 157;
+  fra.me.meth = LOCATE_abstract_collection___ContainerIterator___item;
+  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_abstract_collection___ContainerIterator____container(fra.me.REG[0])!=NIT_NULL);
+  /* ./../lib/standard//collection//abstract_collection.nit:157 */
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    fprintf(stderr, "Uninitialized attribute %s", "_container");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 157);
+    nit_exit(1);
+  }
+  fra.me.REG[0] = ATTR_abstract_collection___ContainerIterator____container(fra.me.REG[0]);
+  fra.me.REG[0] = CALL_abstract_collection___Container___item(fra.me.REG[0])(fra.me.REG[0]);
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+void abstract_collection___ContainerIterator___next(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_abstract_collection;
+  fra.me.line = 159;
+  fra.me.meth = LOCATE_abstract_collection___ContainerIterator___next;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  REGB0 = TAG_Bool(false);
+  /* ./../lib/standard//collection//abstract_collection.nit:159 */
+  ATTR_abstract_collection___ContainerIterator____is_ok(fra.me.REG[0]) = REGB0;
+  stack_frame_head = fra.me.prev;
   return;
 }
-val_t abstract_collection___ContainerIterator___is_ok(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 163, LOCATE_abstract_collection___ContainerIterator___is_ok};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  tracehead = trace.prev;
-  return ATTR_abstract_collection___ContainerIterator____is_ok( self) /*ContainerIterator::_is_ok*/;
-}
-void abstract_collection___ContainerIterator___init(val_t  self, val_t  param0, int* init_table) {
-  struct trace_t trace = {NULL, NULL, 161, LOCATE_abstract_collection___ContainerIterator___init};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  if (init_table[VAL2OBJ(variable[0])->vft[INIT_TABLE_POS_ContainerIterator].i]) return;
-  /* Register variable[2]: Method return value and escape marker */
-  ATTR_abstract_collection___ContainerIterator____container(variable[0]) /*ContainerIterator::_container*/ =  variable[1] /*c*/;
-  return_label20: while(false);
-  init_table[VAL2OBJ(variable[0])->vft[INIT_TABLE_POS_ContainerIterator].i] = 1;
-  tracehead = trace.prev;
+val_t abstract_collection___ContainerIterator___is_ok(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_abstract_collection;
+  fra.me.line = 163;
+  fra.me.meth = LOCATE_abstract_collection___ContainerIterator___is_ok;
+  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_abstract_collection___ContainerIterator____is_ok(fra.me.REG[0])!=NIT_NULL);
+  /* ./../lib/standard//collection//abstract_collection.nit:163 */
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    fprintf(stderr, "Uninitialized attribute %s", "_is_ok");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 163);
+    nit_exit(1);
+  }
+  REGB0 = ATTR_abstract_collection___ContainerIterator____is_ok(fra.me.REG[0]);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+void abstract_collection___ContainerIterator___init(val_t p0, val_t p1, int* init_table){
+  int itpos1 = VAL2OBJ(p0)->vft[INIT_TABLE_POS_ContainerIterator].i;
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+  val_t tmp;
+  if (init_table[itpos1]) return;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_abstract_collection;
+  fra.me.line = 161;
+  fra.me.meth = LOCATE_abstract_collection___ContainerIterator___init;
+  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//collection//abstract_collection.nit:161 */
+  ATTR_abstract_collection___ContainerIterator____container(fra.me.REG[0]) = fra.me.REG[1];
+  stack_frame_head = fra.me.prev;
+  init_table[itpos1] = 1;
   return;
 }
-void abstract_collection___RemovableCollection___clear(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 171, LOCATE_abstract_collection___RemovableCollection___clear};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+void abstract_collection___RemovableCollection___clear(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_abstract_collection;
+  fra.me.line = 171;
+  fra.me.meth = LOCATE_abstract_collection___RemovableCollection___clear;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:171 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 171);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return;
 }
-void abstract_collection___RemovableCollection___remove(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 174, LOCATE_abstract_collection___RemovableCollection___remove};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+void abstract_collection___RemovableCollection___remove(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 174;
+  fra.me.meth = LOCATE_abstract_collection___RemovableCollection___remove;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:174 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 174);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return;
 }
-void abstract_collection___RemovableCollection___remove_all(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 177, LOCATE_abstract_collection___RemovableCollection___remove_all};
-  val_t variable[4];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  while (true) { /*while*/
-    /* Register variable[3]: Result */
-    variable[3] = CALL_abstract_collection___Collection___has(variable[0])(variable[0],  variable[1] /*item*/) /*Collection::has*/;
-    if (!UNTAG_Bool(variable[3])) break; /* while*/
-    CALL_abstract_collection___RemovableCollection___remove(variable[0])(variable[0],  variable[1] /*item*/) /*RemovableCollection::remove*/;
-    continue_22: while(0);
+void abstract_collection___RemovableCollection___remove_all(val_t p0, val_t p1){
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+  val_t REGB0;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_abstract_collection;
+  fra.me.line = 177;
+  fra.me.meth = LOCATE_abstract_collection___RemovableCollection___remove_all;
+  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//collection//abstract_collection.nit:178 */
+  while(1) {
+    REGB0 = CALL_abstract_collection___Collection___has(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+    if (UNTAG_Bool(REGB0)) {
+      CALL_abstract_collection___RemovableCollection___remove(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+    } else {
+      goto label1;
+    }
   }
-  break_22: while(0);
-  return_label21: while(false);
-  tracehead = trace.prev;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
   return;
 }
-void abstract_collection___SimpleCollection___add(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 184, LOCATE_abstract_collection___SimpleCollection___add};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+void abstract_collection___SimpleCollection___add(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 184;
+  fra.me.meth = LOCATE_abstract_collection___SimpleCollection___add;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:184 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 184);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return;
 }
-void abstract_collection___SimpleCollection___add_all(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 188, LOCATE_abstract_collection___SimpleCollection___add_all};
-  val_t variable[6];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Result */
-  variable[3] = TAG_Bool(!UNTAG_Bool(TAG_Bool(( variable[1] /*coll*/ ==  NIT_NULL /*null*/) || (( variable[1] /*coll*/ != NIT_NULL) && ((CALL_kernel___Object_____eqeq( variable[1] /*coll*/)==kernel___Object_____eqeq)?(IS_EQUAL_NN( variable[1] /*coll*/, NIT_NULL /*null*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq( variable[1] /*coll*/)( variable[1] /*coll*/,  NIT_NULL /*null*/) /*Object::==*/)))))));
-  if (UNTAG_Bool(variable[3])) { /*if*/
-    /* Register variable[3]: For iterator */
-    variable[3] = CALL_abstract_collection___Collection___iterator( variable[1] /*coll*/)( variable[1] /*coll*/) /*Collection::iterator*/;
-    while (true) { /*for*/
-      /* Register variable[4]: For 'is_ok' result */
-      variable[4] = CALL_abstract_collection___Iterator___is_ok(variable[3])(variable[3]) /*Iterator::is_ok*/;
-      if (!UNTAG_Bool(variable[4])) break; /*for*/
-      variable[4] = CALL_abstract_collection___Iterator___item(variable[3])(variable[3]) /*Iterator::item*/ /* Ensure var: For item*/;
-      /* Register variable[5]: Local variable */
-      variable[5] = variable[4];
-      CALL_abstract_collection___SimpleCollection___add(variable[0])(variable[0],  variable[5] /*i*/) /*SimpleCollection::add*/;
-      continue_24: while(0);
-      CALL_abstract_collection___Iterator___next(variable[3])(variable[3]) /*Iterator::next*/;
+void abstract_collection___SimpleCollection___add_all(val_t p0, val_t p1){
+  struct {struct stack_frame_t me; val_t MORE_REG[2];} fra;
+  val_t REGB0;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_abstract_collection;
+  fra.me.line = 188;
+  fra.me.meth = LOCATE_abstract_collection___SimpleCollection___add_all;
+  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;
+  fra.me.REG[1] = CALL_abstract_collection___Collection___iterator(fra.me.REG[1])(fra.me.REG[1]);
+  /* ./../lib/standard//collection//abstract_collection.nit:189 */
+  while(1) {
+    REGB0 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[1])(fra.me.REG[1]);
+    if (UNTAG_Bool(REGB0)) {
+      fra.me.REG[2] = CALL_abstract_collection___Iterator___item(fra.me.REG[1])(fra.me.REG[1]);
+      CALL_abstract_collection___SimpleCollection___add(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[2]);
+    } else {
+      goto label1;
     }
-    break_24: while(0);
+    CALL_abstract_collection___Iterator___next(fra.me.REG[1])(fra.me.REG[1]);
   }
-  return_label23: while(false);
-  tracehead = trace.prev;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
   return;
 }
-val_t abstract_collection___Set___has_only(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 204, LOCATE_abstract_collection___Set___has_only};
-  val_t variable[5];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Local variable */
-  /* Register variable[4]: Result */
-  variable[4] = CALL_abstract_collection___Collection___length(variable[0])(variable[0]) /*Collection::length*/;
-  variable[3] = variable[4];
-  /* Register variable[4]: Result */
-  variable[4] = TAG_Bool(( variable[3] /*l*/)==( TAG_Int(1)));
-  if (UNTAG_Bool(variable[4])) { /*if*/
-    /* Register variable[4]: Result */
-    variable[4] = CALL_abstract_collection___Collection___has(variable[0])(variable[0],  variable[1] /*item*/) /*Collection::has*/;
-    variable[2] = variable[4];
-    goto return_label25;
-  } else { /*if*/
-    /* Register variable[4]: Result */
-    variable[4] = TAG_Bool(( variable[3] /*l*/)==( TAG_Int(0)));
-    if (UNTAG_Bool(variable[4])) { /*if*/
-      variable[2] =  TAG_Bool(true);
-      goto return_label25;
-    } else { /*if*/
-      variable[2] =  TAG_Bool(false);
-      goto return_label25;
+val_t abstract_collection___Set___has_only(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 tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_abstract_collection;
+  fra.me.line = 204;
+  fra.me.meth = LOCATE_abstract_collection___Set___has_only;
+  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_abstract_collection___Collection___length(fra.me.REG[0])(fra.me.REG[0]);
+  REGB1 = TAG_Int(1);
+  REGB2 = TAG_Bool(IS_EQUAL_OO(REGB0,REGB1));
+  /* ./../lib/standard//collection//abstract_collection.nit:207 */
+  if (UNTAG_Bool(REGB2)) {
+  } else {
+    REGB1 = TAG_Bool((REGB0)==(REGB1));
+    REGB2 = REGB1;
+  /* ./../lib/standard//collection//abstract_collection.nit:207 */
+  }
+  if (UNTAG_Bool(REGB2)) {
+    REGB2 = CALL_abstract_collection___Collection___has(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+    /* ./../lib/standard//collection//abstract_collection.nit:208 */
+    goto label1;
+  } else {
+    REGB1 = TAG_Int(0);
+    REGB3 = TAG_Bool(IS_EQUAL_OO(REGB0,REGB1));
+    /* ./../lib/standard//collection//abstract_collection.nit:209 */
+    if (UNTAG_Bool(REGB3)) {
+    } else {
+      REGB1 = TAG_Bool((REGB0)==(REGB1));
+      REGB3 = REGB1;
+    /* ./../lib/standard//collection//abstract_collection.nit:209 */
+    }
+    if (UNTAG_Bool(REGB3)) {
+      REGB3 = TAG_Bool(true);
+      REGB2 = REGB3;
+      /* ./../lib/standard//collection//abstract_collection.nit:210 */
+      goto label1;
+    } else {
+      REGB3 = TAG_Bool(false);
+      REGB2 = REGB3;
+      /* ./../lib/standard//collection//abstract_collection.nit:212 */
+      goto label1;
     }
   }
-  return_label25: while(false);
-  tracehead = trace.prev;
-  return variable[2];
-}
-val_t abstract_collection___Set___count(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 216, LOCATE_abstract_collection___Set___count};
-  val_t variable[4];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Result */
-  variable[3] = CALL_abstract_collection___Collection___has(variable[0])(variable[0],  variable[1] /*item*/) /*Collection::has*/;
-  if (UNTAG_Bool(variable[3])) { /*if*/
-    variable[2] =  TAG_Int(1);
-    goto return_label26;
-  } else { /*if*/
-    variable[2] =  TAG_Int(0);
-    goto return_label26;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB2;
+}
+val_t abstract_collection___Set___count(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_abstract_collection;
+  fra.me.line = 216;
+  fra.me.meth = LOCATE_abstract_collection___Set___count;
+  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_abstract_collection___Collection___has(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+  /* ./../lib/standard//collection//abstract_collection.nit:219 */
+  if (UNTAG_Bool(REGB0)) {
+    REGB0 = TAG_Int(1);
+    /* ./../lib/standard//collection//abstract_collection.nit:220 */
+    goto label1;
+  } else {
+    REGB1 = TAG_Int(0);
+    REGB0 = REGB1;
+    /* ./../lib/standard//collection//abstract_collection.nit:222 */
+    goto label1;
   }
-  return_label26: while(false);
-  tracehead = trace.prev;
-  return variable[2];
-}
-void abstract_collection___Set___remove_all(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 226, LOCATE_abstract_collection___Set___remove_all};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  CALL_abstract_collection___RemovableCollection___remove(variable[0])(variable[0],  variable[1] /*item*/) /*RemovableCollection::remove*/;
-  return_label27: while(false);
-  tracehead = trace.prev;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+void abstract_collection___Set___remove_all(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 226;
+  fra.me.meth = LOCATE_abstract_collection___Set___remove_all;
+  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//collection//abstract_collection.nit:227 */
+  CALL_abstract_collection___RemovableCollection___remove(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+  stack_frame_head = fra.me.prev;
   return;
 }
-val_t abstract_collection___MapRead___iterator(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 238, LOCATE_abstract_collection___MapRead___iterator};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___MapRead___iterator(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_abstract_collection;
+  fra.me.line = 238;
+  fra.me.meth = LOCATE_abstract_collection___MapRead___iterator;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:238 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 238);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___MapRead_____bra(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 232, LOCATE_abstract_collection___MapRead_____bra};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___MapRead_____bra(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 232;
+  fra.me.meth = LOCATE_abstract_collection___MapRead_____bra;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:232 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 232);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___MapRead___has_key(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 235, LOCATE_abstract_collection___MapRead___has_key};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___MapRead___has_key(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 235;
+  fra.me.meth = LOCATE_abstract_collection___MapRead___has_key;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:235 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 235);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-void abstract_collection___Map_____braeq(val_t  self, val_t  param0, val_t  param1) {
-  struct trace_t trace = {NULL, NULL, 256, LOCATE_abstract_collection___Map_____braeq};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+void abstract_collection___Map_____braeq(val_t p0, val_t p1, val_t p2){
+  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_abstract_collection;
+  fra.me.line = 256;
+  fra.me.meth = LOCATE_abstract_collection___Map_____braeq;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:256 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 256);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return;
 }
-void abstract_collection___Map___remove_at(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 259, LOCATE_abstract_collection___Map___remove_at};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+void abstract_collection___Map___remove_at(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 259;
+  fra.me.meth = LOCATE_abstract_collection___Map___remove_at;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:259 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 259);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return;
 }
-void abstract_collection___Map___recover_with(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 262, LOCATE_abstract_collection___Map___recover_with};
-  val_t variable[6];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Local variable */
-  /* Register variable[4]: Result */
-  variable[4] = CALL_abstract_collection___Collection___iterator( variable[1] /*map*/)( variable[1] /*map*/) /*MapRead::iterator*/;
-  variable[3] = variable[4];
-  while (true) { /*while*/
-    /* Register variable[4]: Result */
-    variable[4] = CALL_abstract_collection___Iterator___is_ok( variable[3] /*i*/)( variable[3] /*i*/) /*Iterator::is_ok*/;
-    if (!UNTAG_Bool(variable[4])) break; /* while*/
-    /* Register variable[4]: Result */
-    variable[4] = CALL_abstract_collection___MapIterator___key( variable[3] /*i*/)( variable[3] /*i*/) /*MapIterator::key*/;
-    /* Register variable[5]: Result */
-    variable[5] = CALL_abstract_collection___Iterator___item( variable[3] /*i*/)( variable[3] /*i*/) /*Iterator::item*/;
-    CALL_abstract_collection___Map_____braeq(variable[0])(variable[0], variable[4], variable[5]) /*Map::[]=*/;
-    CALL_abstract_collection___Iterator___next( variable[3] /*i*/)( variable[3] /*i*/) /*Iterator::next*/;
-    continue_29: while(0);
+void abstract_collection___Map___recover_with(val_t p0, val_t p1){
+  struct {struct stack_frame_t me; val_t MORE_REG[3];} fra;
+  val_t REGB0;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_abstract_collection;
+  fra.me.line = 262;
+  fra.me.meth = LOCATE_abstract_collection___Map___recover_with;
+  fra.me.has_broke = 0;
+  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;
+  fra.me.REG[1] = p1;
+  fra.me.REG[1] = CALL_abstract_collection___Collection___iterator(fra.me.REG[1])(fra.me.REG[1]);
+  /* ./../lib/standard//collection//abstract_collection.nit:267 */
+  while(1) {
+    REGB0 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[1])(fra.me.REG[1]);
+    if (UNTAG_Bool(REGB0)) {
+      fra.me.REG[2] = CALL_abstract_collection___MapIterator___key(fra.me.REG[1])(fra.me.REG[1]);
+      fra.me.REG[3] = CALL_abstract_collection___Iterator___item(fra.me.REG[1])(fra.me.REG[1]);
+      /* ./../lib/standard//collection//abstract_collection.nit:268 */
+      CALL_abstract_collection___Map_____braeq(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[2], fra.me.REG[3]);
+      /* ./../lib/standard//collection//abstract_collection.nit:269 */
+      CALL_abstract_collection___Iterator___next(fra.me.REG[1])(fra.me.REG[1]);
+    } else {
+      /* ./../lib/standard//collection//abstract_collection.nit:267 */
+      goto label1;
+    }
   }
-  break_29: while(0);
-  return_label28: while(false);
-  tracehead = trace.prev;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
   return;
 }
-val_t abstract_collection___MapIterator___key(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 277, LOCATE_abstract_collection___MapIterator___key};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___MapIterator___key(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_abstract_collection;
+  fra.me.line = 277;
+  fra.me.meth = LOCATE_abstract_collection___MapIterator___key;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:277 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 277);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___IndexedCollectionRead___iterator(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 316, LOCATE_abstract_collection___IndexedCollectionRead___iterator};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___SequenceRead___iterator(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_abstract_collection;
+  fra.me.line = 316;
+  fra.me.meth = LOCATE_abstract_collection___SequenceRead___iterator;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:316 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 316);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___IndexedCollectionRead___first(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 288, LOCATE_abstract_collection___IndexedCollectionRead___first};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Collection___is_empty(variable[0])(variable[0]) /*Collection::is_empty*/;
-  if (!UNTAG_Bool( TAG_Bool(!UNTAG_Bool(variable[2])))) { fprintf(stderr, "Assert%s failed", " 'not_empty' "); fprintf(stderr, " in %s (%s:%d)\n", LOCATE_abstract_collection___IndexedCollectionRead___first, LOCATE_abstract_collection, 292); nit_exit(1);}
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___MapRead_____bra(variable[0])(variable[0],  TAG_Int(0)) /*MapRead::[]*/;
-  variable[1] = variable[2];
-  goto return_label30;
-  return_label30: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-val_t abstract_collection___IndexedCollectionRead___last(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 296, LOCATE_abstract_collection___IndexedCollectionRead___last};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Collection___is_empty(variable[0])(variable[0]) /*Collection::is_empty*/;
-  if (!UNTAG_Bool( TAG_Bool(!UNTAG_Bool(variable[2])))) { fprintf(stderr, "Assert%s failed", " 'not_empty' "); fprintf(stderr, " in %s (%s:%d)\n", LOCATE_abstract_collection___IndexedCollectionRead___last, LOCATE_abstract_collection, 300); nit_exit(1);}
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Collection___length(variable[0])(variable[0]) /*Collection::length*/;
-  /* Register variable[2]: Result */
-  variable[2] = TAG_Int(UNTAG_Int(variable[2])-UNTAG_Int( TAG_Int(1)));
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___MapRead_____bra(variable[0])(variable[0], variable[2]) /*MapRead::[]*/;
-  variable[1] = variable[2];
-  goto return_label31;
-  return_label31: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-val_t abstract_collection___IndexedCollectionRead___index_of(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 304, LOCATE_abstract_collection___IndexedCollectionRead___index_of};
-  val_t variable[5];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Local variable */
-  /* Register variable[4]: Result */
-  variable[4] = CALL_abstract_collection___Collection___iterator(variable[0])(variable[0]) /*IndexedCollectionRead::iterator*/;
-  variable[3] = variable[4];
-  while (true) { /*while*/
-    /* Register variable[4]: Result */
-    variable[4] = CALL_abstract_collection___Iterator___is_ok( variable[3] /*i*/)( variable[3] /*i*/) /*Iterator::is_ok*/;
-    if (!UNTAG_Bool(variable[4])) break; /* while*/
-    /* Register variable[4]: Result */
-    variable[4] = CALL_abstract_collection___Iterator___item( variable[3] /*i*/)( variable[3] /*i*/) /*Iterator::item*/;
-    /* Register variable[4]: Result */
-    variable[4] = TAG_Bool((variable[4] ==  variable[1] /*item*/) || ((variable[4] != NIT_NULL) && ((CALL_kernel___Object_____eqeq(variable[4])==kernel___Object_____eqeq)?(IS_EQUAL_NN(variable[4], variable[1] /*item*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq(variable[4])(variable[4],  variable[1] /*item*/) /*Object::==*/)))));
-    if (UNTAG_Bool(variable[4])) { /*if*/
-      /* Register variable[4]: Result */
-      variable[4] = CALL_abstract_collection___IndexedIterator___index( variable[3] /*i*/)( variable[3] /*i*/) /*IndexedIterator::index*/;
-      variable[2] = variable[4];
-      goto return_label32;
+val_t abstract_collection___SequenceRead___first(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_abstract_collection;
+  fra.me.line = 288;
+  fra.me.meth = LOCATE_abstract_collection___SequenceRead___first;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  REGB0 = CALL_abstract_collection___Collection___is_empty(fra.me.REG[0])(fra.me.REG[0]);
+  REGB0 = TAG_Bool(!UNTAG_Bool(REGB0));
+  /* ./../lib/standard//collection//abstract_collection.nit:292 */
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    fprintf(stderr, "Assert %s  failed", "'not_empty'");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 292);
+    nit_exit(1);
+  }
+  REGB0 = TAG_Int(0);
+  fra.me.REG[0] = CALL_abstract_collection___MapRead_____bra(fra.me.REG[0])(fra.me.REG[0], REGB0);
+  /* ./../lib/standard//collection//abstract_collection.nit:293 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+val_t abstract_collection___SequenceRead___last(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_abstract_collection;
+  fra.me.line = 296;
+  fra.me.meth = LOCATE_abstract_collection___SequenceRead___last;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  REGB0 = CALL_abstract_collection___Collection___is_empty(fra.me.REG[0])(fra.me.REG[0]);
+  REGB0 = TAG_Bool(!UNTAG_Bool(REGB0));
+  /* ./../lib/standard//collection//abstract_collection.nit:300 */
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    fprintf(stderr, "Assert %s  failed", "'not_empty'");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 300);
+    nit_exit(1);
+  }
+  REGB0 = CALL_abstract_collection___Collection___length(fra.me.REG[0])(fra.me.REG[0]);
+  REGB1 = TAG_Int(1);
+  REGB1 = TAG_Int(UNTAG_Int(REGB0)-UNTAG_Int(REGB1));
+  fra.me.REG[0] = CALL_abstract_collection___MapRead_____bra(fra.me.REG[0])(fra.me.REG[0], REGB1);
+  /* ./../lib/standard//collection//abstract_collection.nit:301 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+val_t abstract_collection___SequenceRead___index_of(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_abstract_collection;
+  fra.me.line = 304;
+  fra.me.meth = LOCATE_abstract_collection___SequenceRead___index_of;
+  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;
+  fra.me.REG[0] = CALL_abstract_collection___Collection___iterator(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:309 */
+  while(1) {
+    REGB0 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[0])(fra.me.REG[0]);
+    if (UNTAG_Bool(REGB0)) {
+      fra.me.REG[2] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
+      REGB0 = TAG_Bool(IS_EQUAL_NN(fra.me.REG[2],fra.me.REG[1]));
+      /* ./../lib/standard//collection//abstract_collection.nit:310 */
+      if (UNTAG_Bool(REGB0)) {
+      } 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], fra.me.REG[1]);
+          REGB0 = REGB1;
+        }
+      }
+      if (UNTAG_Bool(REGB0)) {
+        REGB0 = CALL_abstract_collection___IndexedIterator___index(fra.me.REG[0])(fra.me.REG[0]);
+        goto label1;
+      }
+      /* ./../lib/standard//collection//abstract_collection.nit:311 */
+      CALL_abstract_collection___Iterator___next(fra.me.REG[0])(fra.me.REG[0]);
+    } else {
+      /* ./../lib/standard//collection//abstract_collection.nit:309 */
+      goto label2;
     }
-    CALL_abstract_collection___Iterator___next( variable[3] /*i*/)( variable[3] /*i*/) /*Iterator::next*/;
-    continue_33: while(0);
   }
-  break_33: while(0);
-  /* Register variable[4]: Result */
-  variable[4] = TAG_Int(-UNTAG_Int( TAG_Int(1)));
-  variable[2] = variable[4];
-  goto return_label32;
-  return_label32: while(false);
-  tracehead = trace.prev;
-  return variable[2];
-}
-void abstract_collection___IndexedCollection___add(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 342, LOCATE_abstract_collection___IndexedCollection___add};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  CALL_abstract_collection___IndexedCollection___push(variable[0])(variable[0],  variable[1] /*e*/) /*IndexedCollection::push*/;
-  return_label34: while(false);
-  tracehead = trace.prev;
+  label2: while(0);
+  REGB1 = TAG_Int(1);
+  REGB1 = TAG_Int(-UNTAG_Int(REGB1));
+  REGB0 = REGB1;
+  /* ./../lib/standard//collection//abstract_collection.nit:313 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+void abstract_collection___Sequence___add(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 342;
+  fra.me.meth = LOCATE_abstract_collection___Sequence___add;
+  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//collection//abstract_collection.nit:343 */
+  CALL_abstract_collection___Sequence___push(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+  stack_frame_head = fra.me.prev;
   return;
 }
-void abstract_collection___IndexedCollection___first__eq(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 325, LOCATE_abstract_collection___IndexedCollection___first__eq};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  CALL_abstract_collection___Map_____braeq(variable[0])(variable[0],  TAG_Int(0),  variable[1] /*item*/) /*Map::[]=*/;
-  return_label35: while(false);
-  tracehead = trace.prev;
+void abstract_collection___Sequence___first__eq(val_t p0, val_t p1){
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+  val_t REGB0;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_abstract_collection;
+  fra.me.line = 325;
+  fra.me.meth = LOCATE_abstract_collection___Sequence___first__eq;
+  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);
+  /* ./../lib/standard//collection//abstract_collection.nit:328 */
+  CALL_abstract_collection___Map_____braeq(fra.me.REG[0])(fra.me.REG[0], REGB0, fra.me.REG[1]);
+  stack_frame_head = fra.me.prev;
   return;
 }
-void abstract_collection___IndexedCollection___last__eq(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 330, LOCATE_abstract_collection___IndexedCollection___last__eq};
-  val_t variable[5];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Local variable */
-  /* Register variable[4]: Result */
-  variable[4] = CALL_abstract_collection___Collection___length(variable[0])(variable[0]) /*Collection::length*/;
-  variable[3] = variable[4];
-  /* Register variable[4]: Result */
-  variable[4] = TAG_Bool(UNTAG_Int( variable[3] /*l*/)>UNTAG_Int( TAG_Int(0)));
-  if (UNTAG_Bool(variable[4])) { /*if*/
-    /* Register variable[4]: Result */
-    variable[4] = TAG_Int(UNTAG_Int( variable[3] /*l*/)-UNTAG_Int( TAG_Int(1)));
-    CALL_abstract_collection___Map_____braeq(variable[0])(variable[0], variable[4],  variable[1] /*item*/) /*Map::[]=*/;
-  } else { /*if*/
-    CALL_abstract_collection___Map_____braeq(variable[0])(variable[0],  TAG_Int(0),  variable[1] /*item*/) /*Map::[]=*/;
+void abstract_collection___Sequence___last__eq(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_abstract_collection;
+  fra.me.line = 330;
+  fra.me.meth = LOCATE_abstract_collection___Sequence___last__eq;
+  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_abstract_collection___Collection___length(fra.me.REG[0])(fra.me.REG[0]);
+  REGB1 = TAG_Int(0);
+  REGB1 = TAG_Bool(UNTAG_Int(REGB0)>UNTAG_Int(REGB1));
+  /* ./../lib/standard//collection//abstract_collection.nit:335 */
+  if (UNTAG_Bool(REGB1)) {
+    REGB1 = TAG_Int(1);
+    REGB1 = TAG_Int(UNTAG_Int(REGB0)-UNTAG_Int(REGB1));
+    /* ./../lib/standard//collection//abstract_collection.nit:336 */
+    CALL_abstract_collection___Map_____braeq(fra.me.REG[0])(fra.me.REG[0], REGB1, fra.me.REG[1]);
+  } else {
+    REGB1 = TAG_Int(0);
+    /* ./../lib/standard//collection//abstract_collection.nit:338 */
+    CALL_abstract_collection___Map_____braeq(fra.me.REG[0])(fra.me.REG[0], REGB1, fra.me.REG[1]);
   }
-  return_label36: while(false);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return;
 }
-void abstract_collection___IndexedCollection___push(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 345, LOCATE_abstract_collection___IndexedCollection___push};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+void abstract_collection___Sequence___push(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 345;
+  fra.me.meth = LOCATE_abstract_collection___Sequence___push;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:345 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 345);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return;
 }
-void abstract_collection___IndexedCollection___append(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 348, LOCATE_abstract_collection___IndexedCollection___append};
-  val_t variable[6];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Result */
-  variable[3] = TAG_Bool(!UNTAG_Bool(TAG_Bool(( variable[1] /*coll*/ ==  NIT_NULL /*null*/) || (( variable[1] /*coll*/ != NIT_NULL) && ((CALL_kernel___Object_____eqeq( variable[1] /*coll*/)==kernel___Object_____eqeq)?(IS_EQUAL_NN( variable[1] /*coll*/, NIT_NULL /*null*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq( variable[1] /*coll*/)( variable[1] /*coll*/,  NIT_NULL /*null*/) /*Object::==*/)))))));
-  if (UNTAG_Bool(variable[3])) { /*if*/
-    /* Register variable[3]: For iterator */
-    variable[3] = CALL_abstract_collection___Collection___iterator( variable[1] /*coll*/)( variable[1] /*coll*/) /*Collection::iterator*/;
-    while (true) { /*for*/
-      /* Register variable[4]: For 'is_ok' result */
-      variable[4] = CALL_abstract_collection___Iterator___is_ok(variable[3])(variable[3]) /*Iterator::is_ok*/;
-      if (!UNTAG_Bool(variable[4])) break; /*for*/
-      variable[4] = CALL_abstract_collection___Iterator___item(variable[3])(variable[3]) /*Iterator::item*/ /* Ensure var: For item*/;
-      /* Register variable[5]: Local variable */
-      variable[5] = variable[4];
-      CALL_abstract_collection___IndexedCollection___push(variable[0])(variable[0],  variable[5] /*i*/) /*IndexedCollection::push*/;
-      continue_38: while(0);
-      CALL_abstract_collection___Iterator___next(variable[3])(variable[3]) /*Iterator::next*/;
+void abstract_collection___Sequence___append(val_t p0, val_t p1){
+  struct {struct stack_frame_t me; val_t MORE_REG[2];} fra;
+  val_t REGB0;
+  val_t tmp;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_abstract_collection;
+  fra.me.line = 348;
+  fra.me.meth = LOCATE_abstract_collection___Sequence___append;
+  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;
+  fra.me.REG[1] = CALL_abstract_collection___Collection___iterator(fra.me.REG[1])(fra.me.REG[1]);
+  /* ./../lib/standard//collection//abstract_collection.nit:349 */
+  while(1) {
+    REGB0 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[1])(fra.me.REG[1]);
+    if (UNTAG_Bool(REGB0)) {
+      fra.me.REG[2] = CALL_abstract_collection___Iterator___item(fra.me.REG[1])(fra.me.REG[1]);
+      CALL_abstract_collection___Sequence___push(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[2]);
+    } else {
+      goto label1;
     }
-    break_38: while(0);
+    CALL_abstract_collection___Iterator___next(fra.me.REG[1])(fra.me.REG[1]);
   }
-  return_label37: while(false);
-  tracehead = trace.prev;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
   return;
 }
-val_t abstract_collection___IndexedCollection___pop(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 351, LOCATE_abstract_collection___IndexedCollection___pop};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___Sequence___pop(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_abstract_collection;
+  fra.me.line = 351;
+  fra.me.meth = LOCATE_abstract_collection___Sequence___pop;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:351 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 351);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-void abstract_collection___IndexedCollection___unshift(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 354, LOCATE_abstract_collection___IndexedCollection___unshift};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+void abstract_collection___Sequence___unshift(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 354;
+  fra.me.meth = LOCATE_abstract_collection___Sequence___unshift;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:354 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 354);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return;
 }
-val_t abstract_collection___IndexedCollection___shift(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 357, LOCATE_abstract_collection___IndexedCollection___shift};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___Sequence___shift(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_abstract_collection;
+  fra.me.line = 357;
+  fra.me.meth = LOCATE_abstract_collection___Sequence___shift;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:357 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 357);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___IndexedIterator___key(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 369, LOCATE_abstract_collection___IndexedIterator___key};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___IndexedIterator___index(variable[0])(variable[0]) /*IndexedIterator::index*/;
-  variable[1] = variable[2];
-  goto return_label39;
-  return_label39: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-val_t abstract_collection___IndexedIterator___index(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 366, LOCATE_abstract_collection___IndexedIterator___index};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+val_t abstract_collection___IndexedIterator___key(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_abstract_collection;
+  fra.me.line = 369;
+  fra.me.meth = LOCATE_abstract_collection___IndexedIterator___key;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  REGB0 = CALL_abstract_collection___IndexedIterator___index(fra.me.REG[0])(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:370 */
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___IndexedIterator___index(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_abstract_collection;
+  fra.me.line = 366;
+  fra.me.meth = LOCATE_abstract_collection___IndexedIterator___index;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:366 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 366);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___CoupleMap_____bra(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 380, LOCATE_abstract_collection___CoupleMap_____bra};
-  val_t variable[5];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Local variable */
-  /* Register variable[4]: Result */
-  variable[4] = CALL_abstract_collection___CoupleMap___couple_at(variable[0])(variable[0],  variable[1] /*key*/) /*CoupleMap::couple_at*/;
-  variable[3] = variable[4];
-  /* Register variable[4]: Result */
-  variable[4] = TAG_Bool(( variable[3] /*c*/ ==  NIT_NULL /*null*/) || (( variable[3] /*c*/ != NIT_NULL) && ((CALL_kernel___Object_____eqeq( variable[3] /*c*/)==kernel___Object_____eqeq)?(IS_EQUAL_NN( variable[3] /*c*/, NIT_NULL /*null*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq( variable[3] /*c*/)( variable[3] /*c*/,  NIT_NULL /*null*/) /*Object::==*/)))));
-  if (UNTAG_Bool(variable[4])) { /*if*/
-    fprintf(stderr, "Aborted"); fprintf(stderr, " in %s (%s:%d)\n", LOCATE_abstract_collection___CoupleMap_____bra, LOCATE_abstract_collection, 384); nit_exit(1);
-  } else { /*if*/
-    /* Register variable[4]: Result */
-    variable[4] = CALL_abstract_collection___Couple___second( variable[3] /*c*/)( variable[3] /*c*/) /*Couple::second*/;
-    variable[2] = variable[4];
-    goto return_label40;
+val_t abstract_collection___CoupleMap_____bra(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_abstract_collection;
+  fra.me.line = 380;
+  fra.me.meth = LOCATE_abstract_collection___CoupleMap_____bra;
+  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;
+  fra.me.REG[1] = CALL_abstract_collection___CoupleMap___couple_at(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+  REGB0 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
+  /* ./../lib/standard//collection//abstract_collection.nit:383 */
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    REGB1 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
+    if (UNTAG_Bool(REGB1)) {
+      REGB1 = TAG_Bool(false);
+      REGB0 = REGB1;
+    } else {
+      REGB1 = CALL_kernel___Object_____eqeq(fra.me.REG[1])(fra.me.REG[1], NIT_NULL);
+      REGB0 = REGB1;
+    }
+  }
+  if (UNTAG_Bool(REGB0)) {
+    /* ./../lib/standard//collection//abstract_collection.nit:384 */
+    fprintf(stderr, "Aborted");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 384);
+    nit_exit(1);
+  } else {
+    REGB0 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
+    /* ./../lib/standard//collection//abstract_collection.nit:386 */
+    if (UNTAG_Bool(REGB0)) {
+      fprintf(stderr, "Reciever is null");
+      fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 386);
+      nit_exit(1);
+    }
+    fra.me.REG[1] = CALL_abstract_collection___Couple___second(fra.me.REG[1])(fra.me.REG[1]);
+    goto label1;
+  }
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[1];
+}
+val_t abstract_collection___CoupleMap___has_key(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_abstract_collection;
+  fra.me.line = 390;
+  fra.me.meth = LOCATE_abstract_collection___CoupleMap___has_key;
+  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;
+  fra.me.REG[1] = CALL_abstract_collection___CoupleMap___couple_at(fra.me.REG[0])(fra.me.REG[0], fra.me.REG[1]);
+  REGB0 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
+  /* ./../lib/standard//collection//abstract_collection.nit:390 */
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    REGB1 = TAG_Bool(fra.me.REG[1]==NIT_NULL);
+    if (UNTAG_Bool(REGB1)) {
+      REGB1 = TAG_Bool(false);
+      REGB0 = REGB1;
+    } else {
+      REGB1 = CALL_kernel___Object_____eqeq(fra.me.REG[1])(fra.me.REG[1], NIT_NULL);
+      REGB0 = REGB1;
+    }
   }
-  return_label40: while(false);
-  tracehead = trace.prev;
-  return variable[2];
-}
-val_t abstract_collection___CoupleMap___has_key(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 390, LOCATE_abstract_collection___CoupleMap___has_key};
-  val_t variable[4];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Method return value and escape marker */
-  /* Register variable[3]: Result */
-  variable[3] = CALL_abstract_collection___CoupleMap___couple_at(variable[0])(variable[0],  variable[1] /*key*/) /*CoupleMap::couple_at*/;
-  /* Register variable[3]: Result */
-  variable[3] = TAG_Bool(!UNTAG_Bool(TAG_Bool((variable[3] ==  NIT_NULL /*null*/) || ((variable[3] != NIT_NULL) && ((CALL_kernel___Object_____eqeq(variable[3])==kernel___Object_____eqeq)?(IS_EQUAL_NN(variable[3], NIT_NULL /*null*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq(variable[3])(variable[3],  NIT_NULL /*null*/) /*Object::==*/)))))));
-  variable[2] = variable[3];
-  goto return_label41;
-  return_label41: while(false);
-  tracehead = trace.prev;
-  return variable[2];
-}
-val_t abstract_collection___CoupleMap___couple_at(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 376, LOCATE_abstract_collection___CoupleMap___couple_at};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
+  REGB0 = TAG_Bool(!UNTAG_Bool(REGB0));
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___CoupleMap___couple_at(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 376;
+  fra.me.meth = LOCATE_abstract_collection___CoupleMap___couple_at;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 0;
+  /* ./../lib/standard//collection//abstract_collection.nit:376 */
   fprintf(stderr, "Deferred method called");
   fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 376);
   nit_exit(1);
-  tracehead = trace.prev;
+  stack_frame_head = fra.me.prev;
   return NIT_NULL;
 }
-val_t abstract_collection___CoupleMapIterator___item(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 398, LOCATE_abstract_collection___CoupleMapIterator___item};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = ATTR_abstract_collection___CoupleMapIterator____iter(variable[0]) /*CoupleMapIterator::_iter*/;
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Iterator___item(variable[2])(variable[2]) /*Iterator::item*/;
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Couple___second(variable[2])(variable[2]) /*Couple::second*/;
-  variable[1] = variable[2];
-  goto return_label42;
-  return_label42: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-void abstract_collection___CoupleMapIterator___next(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 406, LOCATE_abstract_collection___CoupleMapIterator___next};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = ATTR_abstract_collection___CoupleMapIterator____iter(variable[0]) /*CoupleMapIterator::_iter*/;
-  CALL_abstract_collection___Iterator___next(variable[2])(variable[2]) /*Iterator::next*/;
-  while (true) { /*while*/
-    /* Register variable[2]: Result */
-    variable[2] = ATTR_abstract_collection___CoupleMapIterator____iter(variable[0]) /*CoupleMapIterator::_iter*/;
-    /* Register variable[2]: Result */
-    variable[2] = CALL_abstract_collection___Iterator___is_ok(variable[2])(variable[2]) /*Iterator::is_ok*/;
-    /* Ensure var variable[2]: Left 'and' operand*/
-    if (UNTAG_Bool(variable[2])) { /* and */
-      /* Register variable[2]: Result */
-      variable[2] = ATTR_abstract_collection___CoupleMapIterator____iter(variable[0]) /*CoupleMapIterator::_iter*/;
-      /* Register variable[2]: Result */
-      variable[2] = CALL_abstract_collection___Iterator___item(variable[2])(variable[2]) /*Iterator::item*/;
-      /* Register variable[2]: Result */
-      variable[2] = TAG_Bool((variable[2] ==  NIT_NULL /*null*/) || ((variable[2] != NIT_NULL) && ((CALL_kernel___Object_____eqeq(variable[2])==kernel___Object_____eqeq)?(IS_EQUAL_NN(variable[2], NIT_NULL /*null*/)):(UNTAG_Bool(CALL_kernel___Object_____eqeq(variable[2])(variable[2],  NIT_NULL /*null*/) /*Object::==*/)))));
-    }
-    /* Register variable[2]: Result */
-    if (!UNTAG_Bool(variable[2])) break; /* while*/
-    /* Register variable[2]: Result */
-    variable[2] = ATTR_abstract_collection___CoupleMapIterator____iter(variable[0]) /*CoupleMapIterator::_iter*/;
-    CALL_abstract_collection___Iterator___next(variable[2])(variable[2]) /*Iterator::next*/;
-    continue_44: while(0);
+val_t abstract_collection___CoupleMapIterator___item(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_abstract_collection;
+  fra.me.line = 398;
+  fra.me.meth = LOCATE_abstract_collection___CoupleMapIterator___item;
+  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_abstract_collection___CoupleMapIterator____iter(fra.me.REG[0])!=NIT_NULL);
+  /* ./../lib/standard//collection//abstract_collection.nit:398 */
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    fprintf(stderr, "Uninitialized attribute %s", "_iter");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 398);
+    nit_exit(1);
+  }
+  fra.me.REG[0] = ATTR_abstract_collection___CoupleMapIterator____iter(fra.me.REG[0]);
+  fra.me.REG[0] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
+  REGB0 = TAG_Bool(fra.me.REG[0]==NIT_NULL);
+  if (UNTAG_Bool(REGB0)) {
+    fprintf(stderr, "Reciever is null");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 398);
+    nit_exit(1);
+  }
+  fra.me.REG[0] = CALL_abstract_collection___Couple___second(fra.me.REG[0])(fra.me.REG[0]);
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+void abstract_collection___CoupleMapIterator___next(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_abstract_collection;
+  fra.me.line = 406;
+  fra.me.meth = LOCATE_abstract_collection___CoupleMapIterator___next;
+  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_abstract_collection___CoupleMapIterator____iter(fra.me.REG[0])!=NIT_NULL);
+  /* ./../lib/standard//collection//abstract_collection.nit:408 */
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    fprintf(stderr, "Uninitialized attribute %s", "_iter");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 408);
+    nit_exit(1);
   }
-  break_44: while(0);
-  return_label43: while(false);
-  tracehead = trace.prev;
+  fra.me.REG[0] = ATTR_abstract_collection___CoupleMapIterator____iter(fra.me.REG[0]);
+  CALL_abstract_collection___Iterator___next(fra.me.REG[0])(fra.me.REG[0]);
+  stack_frame_head = fra.me.prev;
   return;
 }
-val_t abstract_collection___CoupleMapIterator___is_ok(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 404, LOCATE_abstract_collection___CoupleMapIterator___is_ok};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = ATTR_abstract_collection___CoupleMapIterator____iter(variable[0]) /*CoupleMapIterator::_iter*/;
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Iterator___is_ok(variable[2])(variable[2]) /*Iterator::is_ok*/;
-  variable[1] = variable[2];
-  goto return_label45;
-  return_label45: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-val_t abstract_collection___CoupleMapIterator___key(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 402, LOCATE_abstract_collection___CoupleMapIterator___key};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Method return value and escape marker */
-  /* Register variable[2]: Result */
-  variable[2] = ATTR_abstract_collection___CoupleMapIterator____iter(variable[0]) /*CoupleMapIterator::_iter*/;
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Iterator___item(variable[2])(variable[2]) /*Iterator::item*/;
-  /* Register variable[2]: Result */
-  variable[2] = CALL_abstract_collection___Couple___first(variable[2])(variable[2]) /*Couple::first*/;
-  variable[1] = variable[2];
-  goto return_label46;
-  return_label46: while(false);
-  tracehead = trace.prev;
-  return variable[1];
-}
-void abstract_collection___CoupleMapIterator___init(val_t  self, val_t  param0, int* init_table) {
-  struct trace_t trace = {NULL, NULL, 414, LOCATE_abstract_collection___CoupleMapIterator___init};
-  val_t variable[3];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  if (init_table[VAL2OBJ(variable[0])->vft[INIT_TABLE_POS_CoupleMapIterator].i]) return;
-  /* Register variable[2]: Method return value and escape marker */
-  ATTR_abstract_collection___CoupleMapIterator____iter(variable[0]) /*CoupleMapIterator::_iter*/ =  variable[1] /*i*/;
-  return_label47: while(false);
-  init_table[VAL2OBJ(variable[0])->vft[INIT_TABLE_POS_CoupleMapIterator].i] = 1;
-  tracehead = trace.prev;
+val_t abstract_collection___CoupleMapIterator___is_ok(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_abstract_collection;
+  fra.me.line = 404;
+  fra.me.meth = LOCATE_abstract_collection___CoupleMapIterator___is_ok;
+  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_abstract_collection___CoupleMapIterator____iter(fra.me.REG[0])!=NIT_NULL);
+  /* ./../lib/standard//collection//abstract_collection.nit:404 */
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    fprintf(stderr, "Uninitialized attribute %s", "_iter");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 404);
+    nit_exit(1);
+  }
+  fra.me.REG[0] = ATTR_abstract_collection___CoupleMapIterator____iter(fra.me.REG[0]);
+  REGB0 = CALL_abstract_collection___Iterator___is_ok(fra.me.REG[0])(fra.me.REG[0]);
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return REGB0;
+}
+val_t abstract_collection___CoupleMapIterator___key(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_abstract_collection;
+  fra.me.line = 402;
+  fra.me.meth = LOCATE_abstract_collection___CoupleMapIterator___key;
+  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_abstract_collection___CoupleMapIterator____iter(fra.me.REG[0])!=NIT_NULL);
+  /* ./../lib/standard//collection//abstract_collection.nit:402 */
+  if (UNTAG_Bool(REGB0)) {
+  } else {
+    fprintf(stderr, "Uninitialized attribute %s", "_iter");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 402);
+    nit_exit(1);
+  }
+  fra.me.REG[0] = ATTR_abstract_collection___CoupleMapIterator____iter(fra.me.REG[0]);
+  fra.me.REG[0] = CALL_abstract_collection___Iterator___item(fra.me.REG[0])(fra.me.REG[0]);
+  REGB0 = TAG_Bool(fra.me.REG[0]==NIT_NULL);
+  if (UNTAG_Bool(REGB0)) {
+    fprintf(stderr, "Reciever is null");
+    fprintf(stderr, " (%s:%d)\n", LOCATE_abstract_collection, 402);
+    nit_exit(1);
+  }
+  fra.me.REG[0] = CALL_abstract_collection___Couple___first(fra.me.REG[0])(fra.me.REG[0]);
+  goto label1;
+  label1: while(0);
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+void abstract_collection___CoupleMapIterator___init(val_t p0, val_t p1, int* init_table){
+  int itpos2 = VAL2OBJ(p0)->vft[INIT_TABLE_POS_CoupleMapIterator].i;
+  struct {struct stack_frame_t me; val_t MORE_REG[1];} fra;
+  val_t tmp;
+  if (init_table[itpos2]) return;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_abstract_collection;
+  fra.me.line = 413;
+  fra.me.meth = LOCATE_abstract_collection___CoupleMapIterator___init;
+  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//collection//abstract_collection.nit:413 */
+  ATTR_abstract_collection___CoupleMapIterator____iter(fra.me.REG[0]) = fra.me.REG[1];
+  stack_frame_head = fra.me.prev;
+  init_table[itpos2] = 1;
   return;
 }
-val_t abstract_collection___Couple___first(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 422, LOCATE_abstract_collection___Couple___first};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  tracehead = trace.prev;
-  return ATTR_abstract_collection___Couple____first( self) /*Couple::_first*/;
-}
-void abstract_collection___Couple___first__eq(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 422, LOCATE_abstract_collection___Couple___first__eq};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  ATTR_abstract_collection___Couple____first( self) /*Couple::_first*/ =  param0;
-  tracehead = trace.prev;
+val_t abstract_collection___Couple___first(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_abstract_collection;
+  fra.me.line = 421;
+  fra.me.meth = LOCATE_abstract_collection___Couple___first;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  fra.me.REG[0] = ATTR_abstract_collection___Couple____first(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:421 */
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+void abstract_collection___Couple___first__eq(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 421;
+  fra.me.meth = LOCATE_abstract_collection___Couple___first__eq;
+  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//collection//abstract_collection.nit:421 */
+  ATTR_abstract_collection___Couple____first(fra.me.REG[0]) = fra.me.REG[1];
+  stack_frame_head = fra.me.prev;
   return;
 }
-val_t abstract_collection___Couple___second(val_t  self) {
-  struct trace_t trace = {NULL, NULL, 425, LOCATE_abstract_collection___Couple___second};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  tracehead = trace.prev;
-  return ATTR_abstract_collection___Couple____second( self) /*Couple::_second*/;
-}
-void abstract_collection___Couple___second__eq(val_t  self, val_t  param0) {
-  struct trace_t trace = {NULL, NULL, 425, LOCATE_abstract_collection___Couple___second__eq};
-  val_t *variable = NULL;
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  ATTR_abstract_collection___Couple____second( self) /*Couple::_second*/ =  param0;
-  tracehead = trace.prev;
+val_t abstract_collection___Couple___second(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_abstract_collection;
+  fra.me.line = 424;
+  fra.me.meth = LOCATE_abstract_collection___Couple___second;
+  fra.me.has_broke = 0;
+  fra.me.REG_size = 1;
+  fra.me.REG[0] = NIT_NULL;
+  fra.me.REG[0] = p0;
+  fra.me.REG[0] = ATTR_abstract_collection___Couple____second(fra.me.REG[0]);
+  /* ./../lib/standard//collection//abstract_collection.nit:424 */
+  stack_frame_head = fra.me.prev;
+  return fra.me.REG[0];
+}
+void abstract_collection___Couple___second__eq(val_t p0, val_t p1){
+  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_abstract_collection;
+  fra.me.line = 424;
+  fra.me.meth = LOCATE_abstract_collection___Couple___second__eq;
+  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//collection//abstract_collection.nit:424 */
+  ATTR_abstract_collection___Couple____second(fra.me.REG[0]) = fra.me.REG[1];
+  stack_frame_head = fra.me.prev;
   return;
 }
-void abstract_collection___Couple___init(val_t  self, val_t  param0, val_t  param1, int* init_table) {
-  struct trace_t trace = {NULL, NULL, 428, LOCATE_abstract_collection___Couple___init};
-  val_t variable[4];
-  struct WBT_ **closurevariable = NULL;
-  trace.prev = tracehead; tracehead = &trace;
-  trace.file = LOCATE_abstract_collection;
-  /* Register variable[0]: Local variable */
-  variable[0] =  self;
-  /* Register variable[1]: Local variable */
-  variable[1] =  param0;
-  /* Register variable[2]: Local variable */
-  variable[2] =  param1;
-  if (init_table[VAL2OBJ(variable[0])->vft[INIT_TABLE_POS_Couple].i]) return;
-  /* Register variable[3]: Method return value and escape marker */
-  ATTR_abstract_collection___Couple____first(variable[0]) /*Couple::_first*/ =  variable[1] /*f*/;
-  ATTR_abstract_collection___Couple____second(variable[0]) /*Couple::_second*/ =  variable[2] /*s*/;
-  return_label48: while(false);
-  init_table[VAL2OBJ(variable[0])->vft[INIT_TABLE_POS_Couple].i] = 1;
-  tracehead = trace.prev;
+void abstract_collection___Couple___init(val_t p0, val_t p1, val_t p2, int* init_table){
+  int itpos3 = VAL2OBJ(p0)->vft[INIT_TABLE_POS_Couple].i;
+  struct {struct stack_frame_t me; val_t MORE_REG[2];} fra;
+  val_t tmp;
+  if (init_table[itpos3]) return;
+  fra.me.prev = stack_frame_head; stack_frame_head = &fra.me;
+  fra.me.file = LOCATE_abstract_collection;
+  fra.me.line = 427;
+  fra.me.meth = LOCATE_abstract_collection___Couple___init;
+  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;
+  fra.me.REG[2] = p2;
+  /* ./../lib/standard//collection//abstract_collection.nit:430 */
+  ATTR_abstract_collection___Couple____first(fra.me.REG[0]) = fra.me.REG[1];
+  /* ./../lib/standard//collection//abstract_collection.nit:431 */
+  ATTR_abstract_collection___Couple____second(fra.me.REG[0]) = fra.me.REG[2];
+  stack_frame_head = fra.me.prev;
+  init_table[itpos3] = 1;
   return;
 }