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

diff --git a/c_src/opts.sep.1.c b/c_src/opts.sep.1.c
index 0ea9f33..22e950f 100644
--- a/c_src/opts.sep.1.c
+++ b/c_src/opts.sep.1.c
@@ -7,7 +7,7 @@ var1 = self->attrs[COLOR_opts__Option___names].val; /* _names on <self:Option> *
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _names");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 19);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -30,7 +30,7 @@ var1 = self->attrs[COLOR_opts__Option___helptext].val; /* _helptext on <self:Opt
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _helptext");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 25);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -53,7 +53,7 @@ var1 = self->attrs[COLOR_opts__Option___errors].val; /* _errors on <self:Option>
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _errors");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 28);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -123,7 +123,7 @@ const struct type* type_struct;
 const char* var_class_name;
 /* Covariant cast for argument 0 (value) <p0:nullable Object> isa nullable VALUE */
 /* <p0:nullable Object> isa nullable VALUE */
-type_struct = self->type->resolution_table->types[COLOR_opts__Option_VTVALUE];
+type_struct = self->type->resolution_table->types[COLOR_nullable_opts__Option_VTVALUE];
 cltype = type_struct->color;
 idtype = type_struct->id;
 if(p0 == NULL) {
@@ -139,7 +139,7 @@ if (!var) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "nullable VALUE", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 37);
-exit(1);
+show_backtrace(1);
 }
 self->attrs[COLOR_opts__Option___value].val = p0; /* _value on <self:Option> */
 RET_LABEL:;
@@ -178,7 +178,7 @@ if (!var2) {
 var_class_name = var1 == NULL ? "null" : var1->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "VALUE", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 41);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 goto RET_LABEL;
@@ -221,7 +221,7 @@ const struct type* type_struct;
 const char* var_class_name;
 /* Covariant cast for argument 0 (default_value) <p0:nullable Object> isa nullable VALUE */
 /* <p0:nullable Object> isa nullable VALUE */
-type_struct = self->type->resolution_table->types[COLOR_opts__Option_VTVALUE];
+type_struct = self->type->resolution_table->types[COLOR_nullable_opts__Option_VTVALUE];
 cltype = type_struct->color;
 idtype = type_struct->id;
 if(p0 == NULL) {
@@ -237,7 +237,7 @@ if (!var) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "nullable VALUE", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 43);
-exit(1);
+show_backtrace(1);
 }
 self->attrs[COLOR_opts__Option___default_value].val = p0; /* _default_value on <self:Option> */
 RET_LABEL:;
@@ -266,7 +266,7 @@ short int var6 /* : Bool */;
 val* var7 /* : Array[String] */;
 /* Covariant cast for argument 1 (default) <p1:nullable Object> isa nullable VALUE */
 /* <p1:nullable Object> isa nullable VALUE */
-type_struct = self->type->resolution_table->types[COLOR_opts__Option_VTVALUE];
+type_struct = self->type->resolution_table->types[COLOR_nullable_opts__Option_VTVALUE];
 cltype = type_struct->color;
 idtype = type_struct->id;
 if(p1 == NULL) {
@@ -282,7 +282,7 @@ if (!var) {
 var_class_name = p1 == NULL ? "null" : p1->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "nullable VALUE", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 46);
-exit(1);
+show_backtrace(1);
 }
 var_help = p0;
 var_default = p1;
@@ -296,7 +296,6 @@ var2 = 0; /* arg is null but recv is not */
 if (var2){
 var3 = NEW_array__Array(&type_array__Arraystring__String);
 ((void (*)(val*))(var3->class->vft[COLOR_array__Array__init]))(var3) /* init on <var3:Array[String]>*/;
-CHECK_NEW_array__Array(var3);
 self->attrs[COLOR_opts__Option___names].val = var3; /* _names on <self:Option> */
 } else {
 var4 = ((val* (*)(val*))(var_names->class->vft[COLOR_array__Collection__to_a]))(var_names) /* to_a on <var_names:nullable Array[String](Array[String])>*/;
@@ -311,7 +310,6 @@ self->attrs[COLOR_opts__Option___default_value].val = var_default; /* _default_v
 self->attrs[COLOR_opts__Option___value].val = var_default; /* _value on <self:Option> */
 var7 = NEW_array__Array(&type_array__Arraystring__String);
 ((void (*)(val*))(var7->class->vft[COLOR_array__Array__init]))(var7) /* init on <var7:Array[String]>*/;
-CHECK_NEW_array__Array(var7);
 self->attrs[COLOR_opts__Option___errors].val = var7; /* _errors on <self:Option> */
 RET_LABEL:;
 }
@@ -329,7 +327,7 @@ var = self->attrs[COLOR_opts__Option___names].val; /* _names on <self:Option> */
 if (var == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _names");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 63);
-exit(1);
+show_backtrace(1);
 }
 ((void (*)(val*, val*))(var->class->vft[COLOR_abstract_collection__SimpleCollection__add_all]))(var, var_names) /* add_all on <var:Array[String]>*/;
 RET_LABEL:;
@@ -414,13 +412,12 @@ var2 = var5;
 varonce = var2;
 }
 ((void (*)(val*, val*))(var1->class->vft[COLOR_string__Buffer__from]))(var1, var2) /* from on <var1:Buffer>*/;
-CHECK_NEW_string__Buffer(var1);
 var_text = var1;
 var6 = self->attrs[COLOR_opts__Option___names].val; /* _names on <self:Option> */
 if (var6 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _names");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 72);
-exit(1);
+show_backtrace(1);
 }
 if (varonce7) {
 var8 = varonce7;
@@ -459,8 +456,8 @@ var25 = 1; /* easy <var22:Int> isa OTHER*/
 if (!var25) {
 var_class_name = type_kernel__Int.name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "OTHER", var_class_name);
-fprintf(stderr, " (%s:%d)\n", "lib/standard/kernel.nit", 263);
-exit(1);
+fprintf(stderr, " (%s:%d)\n", "lib/standard/kernel.nit", 267);
+show_backtrace(1);
 }
 var26 = var_rest > var22;
 var23 = var26;
@@ -536,7 +533,6 @@ if (var3){
 var4 = NEW_array__Array(&type_array__Arraykernel__Object);
 var5 = 3;
 ((void (*)(val*, long))(var4->class->vft[COLOR_array__Array__with_capacity]))(var4, var5) /* with_capacity on <var4:Array[Object]>*/;
-CHECK_NEW_array__Array(var4);
 var_ = var4;
 if (varonce) {
 var6 = varonce;
@@ -748,7 +744,7 @@ const char* var_class_name;
 var_class_name = self == NULL ? "null" : self->type->name;
 fprintf(stderr, "Runtime error: Abstract method `%s` called on `%s`", "convert", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 133);
-exit(1);
+show_backtrace(1);
 RET_LABEL:;
 return var;
 }
@@ -796,101 +792,102 @@ short int var /* : Bool */;
 short int var1 /* : Bool */;
 short int var_ /* var : Bool */;
 val* var2 /* : nullable Object */;
-val* var3 /* : nullable Object */;
-char var4 /* : Char */;
-short int var5 /* : Bool */;
-short int var7 /* : Bool */;
-char var8 /* : Char */;
-short int var9 /* : Bool */;
-val* var10 /* : nullable Object */;
+val* var3 /* : StringCharView */;
+val* var4 /* : nullable Object */;
+char var5 /* : Char */;
+short int var6 /* : Bool */;
+short int var8 /* : Bool */;
+char var9 /* : Char */;
+short int var10 /* : Bool */;
 val* var11 /* : nullable Object */;
-short int var12 /* : Bool */;
-val* var13 /* : Array[String] */;
+val* var12 /* : nullable Object */;
+short int var13 /* : Bool */;
+val* var14 /* : Array[String] */;
 static val* varonce;
-val* var14 /* : String */;
-char* var15 /* : NativeString */;
-long var16 /* : Int */;
-val* var17 /* : String */;
-val* var18 /* : Array[String] */;
-val* var19 /* : nullable Object */;
-static val* varonce20;
-val* var21 /* : String */;
-char* var22 /* : NativeString */;
-long var23 /* : Int */;
-val* var24 /* : String */;
-val* var25 /* : Array[Object] */;
-long var26 /* : Int */;
-val* var27 /* : NativeArray[Object] */;
-val* var28 /* : String */;
+val* var15 /* : String */;
+char* var16 /* : NativeString */;
+long var17 /* : Int */;
+val* var18 /* : String */;
+val* var19 /* : Array[String] */;
+val* var20 /* : nullable Object */;
+static val* varonce21;
+val* var22 /* : String */;
+char* var23 /* : NativeString */;
+long var24 /* : Int */;
+val* var25 /* : String */;
+val* var26 /* : Array[Object] */;
+long var27 /* : Int */;
+val* var28 /* : NativeArray[Object] */;
+val* var29 /* : String */;
 var_it = p0;
 ((void (*)(val*, val*))(self->class->vft[COLOR_opts__OptionParameter__read_param]))(self, p0) /* read_param on <self:OptionParameter>*/;
 var1 = ((short int (*)(val*))(var_it->class->vft[COLOR_abstract_collection__Iterator__is_ok]))(var_it) /* is_ok on <var_it:Iterator[String]>*/;
 var_ = var1;
 if (var1){
 var2 = ((val* (*)(val*))(var_it->class->vft[COLOR_abstract_collection__Iterator__item]))(var_it) /* item on <var_it:Iterator[String]>*/;
-var3 = ((val* (*)(val*))(var2->class->vft[COLOR_abstract_collection__Collection__first]))(var2) /* first on <var2:nullable Object(String)>*/;
-var4 = '-';
-{ /* Inline kernel#Char#!= (var3,var4) */
-var7 = (var3 != NULL) && (var3->class == &class_kernel__Char);
-if (var7) {
-var8 = ((struct instance_kernel__Char*)var3)->value; /* autounbox from nullable Object to Char */;
-var7 = (var8 == var4);
-}
-var9 = !var7;
-var5 = var9;
-goto RET_LABEL6;
-RET_LABEL6:(void)0;
-}
-var = var5;
+var3 = ((val* (*)(val*))(var2->class->vft[COLOR_string__AbstractString__chars]))(var2) /* chars on <var2:nullable Object(String)>*/;
+var4 = ((val* (*)(val*))(var3->class->vft[COLOR_abstract_collection__Collection__first]))(var3) /* first on <var3:StringCharView>*/;
+var5 = '-';
+{ /* Inline kernel#Char#!= (var4,var5) */
+var8 = (var4 != NULL) && (var4->class == &class_kernel__Char);
+if (var8) {
+var9 = ((struct instance_kernel__Char*)var4)->value; /* autounbox from nullable Object to Char */;
+var8 = (var9 == var5);
+}
+var10 = !var8;
+var6 = var10;
+goto RET_LABEL7;
+RET_LABEL7:(void)0;
+}
+var = var6;
 } else {
 var = var_;
 }
 if (var){
-var10 = ((val* (*)(val*))(var_it->class->vft[COLOR_abstract_collection__Iterator__item]))(var_it) /* item on <var_it:Iterator[String]>*/;
-var11 = ((val* (*)(val*, val*))(self->class->vft[COLOR_opts__OptionParameter__convert]))(self, var10) /* convert on <self:OptionParameter>*/;
-((void (*)(val*, val*))(self->class->vft[COLOR_opts__Option__value_61d]))(self, var11) /* value= on <self:OptionParameter>*/;
+var11 = ((val* (*)(val*))(var_it->class->vft[COLOR_abstract_collection__Iterator__item]))(var_it) /* item on <var_it:Iterator[String]>*/;
+var12 = ((val* (*)(val*, val*))(self->class->vft[COLOR_opts__OptionParameter__convert]))(self, var11) /* convert on <self:OptionParameter>*/;
+((void (*)(val*, val*))(self->class->vft[COLOR_opts__Option__value_61d]))(self, var12) /* value= on <self:OptionParameter>*/;
 ((void (*)(val*))(var_it->class->vft[COLOR_abstract_collection__Iterator__next]))(var_it) /* next on <var_it:Iterator[String]>*/;
 } else {
-var12 = self->attrs[COLOR_opts__OptionParameter___parameter_mandatory].s; /* _parameter_mandatory on <self:OptionParameter> */
-if (var12){
-var13 = self->attrs[COLOR_opts__Option___errors].val; /* _errors on <self:OptionParameter> */
-if (var13 == NULL) {
+var13 = self->attrs[COLOR_opts__OptionParameter___parameter_mandatory].s; /* _parameter_mandatory on <self:OptionParameter> */
+if (var13){
+var14 = self->attrs[COLOR_opts__Option___errors].val; /* _errors on <self:OptionParameter> */
+if (var14 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _errors");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 146);
-exit(1);
+show_backtrace(1);
 }
 if (varonce) {
-var14 = varonce;
+var15 = varonce;
 } else {
-var15 = "Parameter expected for option ";
-var16 = 30;
-var17 = string__NativeString__to_s_with_length(var15, var16);
-var14 = var17;
-varonce = var14;
+var16 = "Parameter expected for option ";
+var17 = 30;
+var18 = string__NativeString__to_s_with_length(var16, var17);
+var15 = var18;
+varonce = var15;
 }
-var18 = ((val* (*)(val*))(self->class->vft[COLOR_opts__Option__names]))(self) /* names on <self:OptionParameter>*/;
-var19 = ((val* (*)(val*))(var18->class->vft[COLOR_abstract_collection__Collection__first]))(var18) /* first on <var18:Array[String]>*/;
-if (varonce20) {
-var21 = varonce20;
+var19 = ((val* (*)(val*))(self->class->vft[COLOR_opts__Option__names]))(self) /* names on <self:OptionParameter>*/;
+var20 = ((val* (*)(val*))(var19->class->vft[COLOR_abstract_collection__Collection__first]))(var19) /* first on <var19:Array[String]>*/;
+if (varonce21) {
+var22 = varonce21;
 } else {
-var22 = ".";
-var23 = 1;
-var24 = string__NativeString__to_s_with_length(var22, var23);
-var21 = var24;
-varonce20 = var21;
-}
-var25 = NEW_array__Array(&type_array__Arraykernel__Object);
-{ /* var25 = array_instance Array[Object] */
-var26 = 3;
-var27 = NEW_array__NativeArray(var26, &type_array__NativeArraykernel__Object);
-((struct instance_array__NativeArray*)var27)->values[0] = (val*) var14;
-((struct instance_array__NativeArray*)var27)->values[1] = (val*) var19;
-((struct instance_array__NativeArray*)var27)->values[2] = (val*) var21;
-((void (*)(val*, val*, long))(var25->class->vft[COLOR_array__Array__with_native]))(var25, var27, var26) /* with_native on <var25:Array[Object]>*/;
-CHECK_NEW_array__Array(var25);
-}
-var28 = ((val* (*)(val*))(var25->class->vft[COLOR_string__Object__to_s]))(var25) /* to_s on <var25:Array[Object]>*/;
-((void (*)(val*, val*))(var13->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var13, var28) /* add on <var13:Array[String]>*/;
+var23 = ".";
+var24 = 1;
+var25 = string__NativeString__to_s_with_length(var23, var24);
+var22 = var25;
+varonce21 = var22;
+}
+var26 = NEW_array__Array(&type_array__Arraykernel__Object);
+{ /* var26 = array_instance Array[Object] */
+var27 = 3;
+var28 = NEW_array__NativeArray(var27, &type_array__NativeArraykernel__Object);
+((struct instance_array__NativeArray*)var28)->values[0] = (val*) var15;
+((struct instance_array__NativeArray*)var28)->values[1] = (val*) var20;
+((struct instance_array__NativeArray*)var28)->values[2] = (val*) var22;
+((void (*)(val*, val*, long))(var26->class->vft[COLOR_array__Array__with_native]))(var26, var28, var27) /* with_native on <var26:Array[Object]>*/;
+}
+var29 = ((val* (*)(val*))(var26->class->vft[COLOR_string__Object__to_s]))(var26) /* to_s on <var26:Array[Object]>*/;
+((void (*)(val*, val*))(var14->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var14, var29) /* add on <var14:Array[String]>*/;
 } else {
 }
 }
@@ -914,7 +911,7 @@ val* var_n /* var n: nullable Array[String] */;
 short int var1 /* : Bool */;
 /* Covariant cast for argument 1 (d) <p1:nullable Object> isa nullable VALUE */
 /* <p1:nullable Object> isa nullable VALUE */
-type_struct = self->type->resolution_table->types[COLOR_opts__Option_VTVALUE];
+type_struct = self->type->resolution_table->types[COLOR_nullable_opts__Option_VTVALUE];
 cltype = type_struct->color;
 idtype = type_struct->id;
 if(p1 == NULL) {
@@ -930,7 +927,7 @@ if (!var) {
 var_class_name = p1 == NULL ? "null" : p1->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "nullable VALUE", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 151);
-exit(1);
+show_backtrace(1);
 }
 var_h = p0;
 var_d = p1;
@@ -984,7 +981,7 @@ if (!var1) {
 var_class_name = var_str == NULL ? "null" : var_str->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "VALUE", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 164);
-exit(1);
+show_backtrace(1);
 }
 var = var_str;
 goto RET_LABEL;
@@ -1049,8 +1046,8 @@ var4 = 1; /* easy <var1:Int> isa OTHER*/
 if (!var4) {
 var_class_name = type_kernel__Int.name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "OTHER", var_class_name);
-fprintf(stderr, " (%s:%d)\n", "lib/standard/kernel.nit", 263);
-exit(1);
+fprintf(stderr, " (%s:%d)\n", "lib/standard/kernel.nit", 267);
+show_backtrace(1);
 }
 var5 = var > var1;
 var2 = var5;
@@ -1060,7 +1057,7 @@ RET_LABEL3:(void)0;
 if (!var2) {
 fprintf(stderr, "Runtime error: %s", "Assert failed");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 174);
-exit(1);
+show_backtrace(1);
 }
 var6 = ((val* (*)(val*))(var_values->class->vft[COLOR_array__Collection__to_a]))(var_values) /* to_a on <var_values:Array[String]>*/;
 self->attrs[COLOR_opts__OptionEnum___values].val = var6; /* _values on <self:OptionEnum> */
@@ -1101,7 +1098,6 @@ var24 = NEW_array__NativeArray(var23, &type_array__NativeArraykernel__Object);
 ((struct instance_array__NativeArray*)var24)->values[2] = (val*) var16;
 ((struct instance_array__NativeArray*)var24)->values[3] = (val*) var18;
 ((void (*)(val*, val*, long))(var22->class->vft[COLOR_array__Array__with_native]))(var22, var24, var23) /* with_native on <var22:Array[Object]>*/;
-CHECK_NEW_array__Array(var22);
 }
 var25 = ((val* (*)(val*))(var22->class->vft[COLOR_string__Object__to_s]))(var22) /* to_s on <var22:Array[Object]>*/;
 var26 = BOX_kernel__Int(var_default); /* autobox from Int to nullable Object */
@@ -1175,7 +1171,7 @@ var1 = self->attrs[COLOR_opts__OptionEnum___values].val; /* _values on <self:Opt
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _values");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 181);
-exit(1);
+show_backtrace(1);
 }
 var2 = ((long (*)(val*, val*))(var1->class->vft[COLOR_abstract_collection__SequenceRead__index_of]))(var1, var_str) /* index_of on <var1:Array[String]>*/;
 var_id = var2;
@@ -1196,7 +1192,6 @@ if (var7){
 var10 = NEW_array__Array(&type_array__Arraykernel__Object);
 var11 = 3;
 ((void (*)(val*, long))(var10->class->vft[COLOR_array__Array__with_capacity]))(var10, var11) /* with_capacity on <var10:Array[Object]>*/;
-CHECK_NEW_array__Array(var10);
 var_ = var10;
 if (varonce) {
 var12 = varonce;
@@ -1212,7 +1207,7 @@ var16 = self->attrs[COLOR_opts__Option___names].val; /* _names on <self:OptionEn
 if (var16 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _names");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 183);
-exit(1);
+show_backtrace(1);
 }
 if (varonce17) {
 var18 = varonce17;
@@ -1240,7 +1235,6 @@ var_e = var28;
 var29 = NEW_array__Array(&type_array__Arraykernel__Object);
 var30 = 3;
 ((void (*)(val*, long))(var29->class->vft[COLOR_array__Array__with_capacity]))(var29, var30) /* with_capacity on <var29:Array[Object]>*/;
-CHECK_NEW_array__Array(var29);
 var_31 = var29;
 if (varonce32) {
 var33 = varonce32;
@@ -1256,7 +1250,7 @@ var37 = self->attrs[COLOR_opts__OptionEnum___values].val; /* _values on <self:Op
 if (var37 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _values");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 184);
-exit(1);
+show_backtrace(1);
 }
 if (varonce38) {
 var39 = varonce38;
@@ -1286,7 +1280,7 @@ var51 = self->attrs[COLOR_opts__Option___errors].val; /* _errors on <self:Option
 if (var51 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _errors");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 185);
-exit(1);
+show_backtrace(1);
 }
 ((void (*)(val*, val*))(var51->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var51, var_e) /* add on <var51:Array[String]>*/;
 } else {
@@ -1318,7 +1312,7 @@ var1 = self->attrs[COLOR_opts__OptionEnum___values].val; /* _values on <self:Opt
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _values");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 190);
-exit(1);
+show_backtrace(1);
 }
 var2 = ((val* (*)(val*))(self->class->vft[COLOR_opts__Option__value]))(self) /* value on <self:OptionEnum>*/;
 var4 = ((struct instance_kernel__Int*)var2)->value; /* autounbox from nullable Object to Int */;
@@ -1377,7 +1371,6 @@ if (var3){
 var4 = NEW_array__Array(&type_array__Arraykernel__Object);
 var5 = 3;
 ((void (*)(val*, long))(var4->class->vft[COLOR_array__Array__with_capacity]))(var4, var5) /* with_capacity on <var4:Array[Object]>*/;
-CHECK_NEW_array__Array(var4);
 var_ = var4;
 if (varonce) {
 var6 = varonce;
@@ -1393,13 +1386,13 @@ var10 = self->attrs[COLOR_opts__OptionEnum___values].val; /* _values on <self:Op
 if (var10 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _values");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 195);
-exit(1);
+show_backtrace(1);
 }
 var11 = ((val* (*)(val*))(self->class->vft[COLOR_opts__Option__default_value]))(self) /* default_value on <self:OptionEnum>*/;
 if (var11 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Cast failed");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 195);
-exit(1);
+show_backtrace(1);
 }
 var13 = ((struct instance_kernel__Int*)var11)->value; /* autounbox from nullable Int to Int */;
 var12 = ((val* (*)(val*, long))(var10->class->vft[COLOR_abstract_collection__SequenceRead___91d_93d]))(var10, var13) /* [] on <var10:Array[String]>*/;
@@ -1498,16 +1491,15 @@ var_help = p0;
 var_names = p1;
 var = NEW_array__Array(&type_array__Arraystring__String);
 ((void (*)(val*))(var->class->vft[COLOR_array__Array__init]))(var) /* init on <var:Array[String]>*/;
-CHECK_NEW_array__Array(var);
 self->attrs[COLOR_opts__OptionArray___values].val = var; /* _values on <self:OptionArray> */
 var1 = self->attrs[COLOR_opts__OptionArray___values].val; /* _values on <self:OptionArray> */
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _values");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 218);
-exit(1);
+show_backtrace(1);
 }
 /* <var1:Array[String]> isa nullable VALUE */
-type_struct = self->type->resolution_table->types[COLOR_opts__Option_VTVALUE];
+type_struct = self->type->resolution_table->types[COLOR_nullable_opts__Option_VTVALUE];
 cltype = type_struct->color;
 idtype = type_struct->id;
 if(cltype >= var1->type->table_size) {
@@ -1519,7 +1511,7 @@ if (!var2) {
 var_class_name = var1 == NULL ? "null" : var1->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "nullable VALUE", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 218);
-exit(1);
+show_backtrace(1);
 }
 ((void (*)(val*, val*, val*, val*))(self->class->vft[COLOR_opts__OptionParameter__init_opt]))(self, var_help, var1, var_names) /* init_opt on <self:OptionArray>*/;
 RET_LABEL:;
@@ -1545,14 +1537,14 @@ var1 = self->attrs[COLOR_opts__OptionArray___values].val; /* _values on <self:Op
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _values");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 224);
-exit(1);
+show_backtrace(1);
 }
 ((void (*)(val*, val*))(var1->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var1, var_str) /* add on <var1:Array[String]>*/;
 var2 = self->attrs[COLOR_opts__OptionArray___values].val; /* _values on <self:OptionArray> */
 if (var2 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _values");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 225);
-exit(1);
+show_backtrace(1);
 }
 /* <var2:Array[String]> isa VALUE */
 type_struct = self->type->resolution_table->types[COLOR_opts__Option_VTVALUE];
@@ -1567,7 +1559,7 @@ if (!var3) {
 var_class_name = var2 == NULL ? "null" : var2->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "VALUE", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 225);
-exit(1);
+show_backtrace(1);
 }
 var = var2;
 goto RET_LABEL;
@@ -1591,7 +1583,7 @@ var1 = self->attrs[COLOR_opts__OptionContext___options].val; /* _options on <sel
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _options");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 230);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1614,7 +1606,7 @@ var1 = self->attrs[COLOR_opts__OptionContext___rest].val; /* _rest on <self:Opti
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _rest");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 231);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1637,7 +1629,7 @@ var1 = self->attrs[COLOR_opts__OptionContext___errors].val; /* _errors on <self:
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _errors");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 232);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1692,7 +1684,7 @@ var1 = self->attrs[COLOR_opts__OptionContext___options].val; /* _options on <sel
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _options");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 239);
-exit(1);
+show_backtrace(1);
 }
 var2 = ((val* (*)(val*))(var1->class->vft[COLOR_abstract_collection__Collection__iterator]))(var1) /* iterator on <var1:Array[Option]>*/;
 for(;;) {
@@ -1735,8 +1727,8 @@ var20 = 1; /* easy <var_l:Int> isa OTHER*/
 if (!var20) {
 var_class_name = type_kernel__Int.name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "OTHER", var_class_name);
-fprintf(stderr, " (%s:%d)\n", "lib/standard/kernel.nit", 261);
-exit(1);
+fprintf(stderr, " (%s:%d)\n", "lib/standard/kernel.nit", 265);
+show_backtrace(1);
 }
 var21 = var_lmax < var_l;
 var18 = var21;
@@ -1755,7 +1747,7 @@ var23 = self->attrs[COLOR_opts__OptionContext___options].val; /* _options on <se
 if (var23 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _options");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 247);
-exit(1);
+show_backtrace(1);
 }
 var24 = ((val* (*)(val*))(var23->class->vft[COLOR_abstract_collection__Collection__iterator]))(var23) /* iterator on <var23:Array[Option]>*/;
 for(;;) {
@@ -1845,59 +1837,60 @@ val* var38 /* : String */;
 char* var39 /* : NativeString */;
 long var40 /* : Int */;
 val* var41 /* : String */;
-val* var42 /* : nullable Object */;
-val* var43 /* : String */;
-char var44 /* : Char */;
-val* var45 /* : String */;
+val* var42 /* : StringCharView */;
+val* var43 /* : nullable Object */;
+val* var44 /* : String */;
+char var45 /* : Char */;
+val* var46 /* : String */;
 val* var_short_opt /* var short_opt: String */;
-val* var46 /* : Map[String, Option] */;
-short int var47 /* : Bool */;
-val* var48 /* : Map[String, Option] */;
-val* var49 /* : nullable Object */;
+val* var47 /* : Map[String, Option] */;
+short int var48 /* : Bool */;
+val* var49 /* : Map[String, Option] */;
+val* var50 /* : nullable Object */;
 val* var_option /* var option: Option */;
-short int var50 /* : Bool */;
-int cltype51;
-int idtype52;
-short int var53 /* : Bool */;
+short int var51 /* : Bool */;
+int cltype52;
+int idtype53;
 short int var54 /* : Bool */;
-val* var55 /* : Map[String, Option] */;
-short int var56 /* : Bool */;
-val* var57 /* : Map[String, Option] */;
-val* var58 /* : nullable Object */;
-val* var_opt /* var opt: Option */;
+short int var55 /* : Bool */;
+val* var56 /* : Map[String, Option] */;
+short int var57 /* : Bool */;
+val* var58 /* : Map[String, Option] */;
 val* var59 /* : nullable Object */;
-val* var61 /* : Array[Option] */;
-val* var62 /* : Iterator[nullable Object] */;
-short int var63 /* : Bool */;
-val* var64 /* : nullable Object */;
-val* var_opt65 /* var opt: Option */;
-short int var66 /* : Bool */;
+val* var_opt /* var opt: Option */;
+val* var60 /* : nullable Object */;
+val* var62 /* : Array[Option] */;
+val* var63 /* : Iterator[nullable Object] */;
+short int var64 /* : Bool */;
+val* var65 /* : nullable Object */;
+val* var_opt66 /* var opt: Option */;
 short int var67 /* : Bool */;
-short int var_68 /* var : Bool */;
-short int var69 /* : Bool */;
+short int var68 /* : Bool */;
+short int var_69 /* var : Bool */;
 short int var70 /* : Bool */;
-val* var71 /* : Array[String] */;
-static val* varonce72;
-val* var73 /* : String */;
-char* var74 /* : NativeString */;
-long var75 /* : Int */;
-val* var76 /* : String */;
-val* var77 /* : Array[String] */;
-static val* varonce78;
-val* var79 /* : String */;
-char* var80 /* : NativeString */;
-long var81 /* : Int */;
-val* var82 /* : String */;
+short int var71 /* : Bool */;
+val* var72 /* : Array[String] */;
+static val* varonce73;
+val* var74 /* : String */;
+char* var75 /* : NativeString */;
+long var76 /* : Int */;
+val* var77 /* : String */;
+val* var78 /* : Array[String] */;
+static val* varonce79;
+val* var80 /* : String */;
+char* var81 /* : NativeString */;
+long var82 /* : Int */;
 val* var83 /* : String */;
-static val* varonce84;
-val* var85 /* : String */;
-char* var86 /* : NativeString */;
-long var87 /* : Int */;
-val* var88 /* : String */;
-val* var89 /* : Array[Object] */;
-long var90 /* : Int */;
-val* var91 /* : NativeArray[Object] */;
-val* var92 /* : String */;
+val* var84 /* : String */;
+static val* varonce85;
+val* var86 /* : String */;
+char* var87 /* : NativeString */;
+long var88 /* : Int */;
+val* var89 /* : String */;
+val* var90 /* : Array[Object] */;
+long var91 /* : Int */;
+val* var92 /* : NativeArray[Object] */;
+val* var93 /* : String */;
 var_it = p0;
 var = 1;
 var_parseargs = var;
@@ -1906,7 +1899,7 @@ var1 = self->attrs[COLOR_opts__OptionContext___rest].val; /* _rest on <self:Opti
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _rest");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 263);
-exit(1);
+show_backtrace(1);
 }
 var_rest = var1;
 for(;;) {
@@ -1958,8 +1951,8 @@ var25 = 1; /* easy <var22:Int> isa OTHER*/
 if (!var25) {
 var_class_name = type_kernel__Int.name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "OTHER", var_class_name);
-fprintf(stderr, " (%s:%d)\n", "lib/standard/kernel.nit", 263);
-exit(1);
+fprintf(stderr, " (%s:%d)\n", "lib/standard/kernel.nit", 267);
+show_backtrace(1);
 }
 var26 = var21 > var22;
 var23 = var26;
@@ -1979,7 +1972,6 @@ var30 = ((long (*)(val*))(var_str->class->vft[COLOR_abstract_collection__Collect
 var31 = BOX_kernel__Int(var29); /* autobox from Int to Discrete */
 var32 = BOX_kernel__Int(var30); /* autobox from Int to Discrete */
 ((void (*)(val*, val*, val*))(var28->class->vft[COLOR_range__Range__init]))(var28, var31, var32) /* init on <var28:Range[Int]>*/;
-CHECK_NEW_range__Range(var28);
 var33 = ((val* (*)(val*))(var28->class->vft[COLOR_abstract_collection__Collection__iterator]))(var28) /* iterator on <var28:Range[Int]>*/;
 for(;;) {
 var34 = ((short int (*)(val*))(var33->class->vft[COLOR_abstract_collection__Iterator__is_ok]))(var33) /* is_ok on <var33:Iterator[nullable Object]>*/;
@@ -1996,39 +1988,40 @@ var41 = string__NativeString__to_s_with_length(var39, var40);
 var38 = var41;
 varonce37 = var38;
 }
-var42 = ((val* (*)(val*, long))(var_str->class->vft[COLOR_abstract_collection__SequenceRead___91d_93d]))(var_str, var_i) /* [] on <var_str:String>*/;
-var44 = ((struct instance_kernel__Char*)var42)->value; /* autounbox from nullable Object to Char */;
-var43 = string__Char__to_s(var44);
-var45 = ((val* (*)(val*, val*))(var38->class->vft[COLOR_string__String___43d]))(var38, var43) /* + on <var38:String>*/;
-var_short_opt = var45;
-var46 = self->attrs[COLOR_opts__OptionContext___optmap].val; /* _optmap on <self:OptionContext> */
-if (var46 == NULL) {
+var42 = ((val* (*)(val*))(var_str->class->vft[COLOR_string__AbstractString__chars]))(var_str) /* chars on <var_str:String>*/;
+var43 = ((val* (*)(val*, long))(var42->class->vft[COLOR_abstract_collection__SequenceRead___91d_93d]))(var42, var_i) /* [] on <var42:StringCharView>*/;
+var45 = ((struct instance_kernel__Char*)var43)->value; /* autounbox from nullable Object to Char */;
+var44 = string__Char__to_s(var45);
+var46 = ((val* (*)(val*, val*))(var38->class->vft[COLOR_string__String___43d]))(var38, var44) /* + on <var38:String>*/;
+var_short_opt = var46;
+var47 = self->attrs[COLOR_opts__OptionContext___optmap].val; /* _optmap on <self:OptionContext> */
+if (var47 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _optmap");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 277);
-exit(1);
+show_backtrace(1);
 }
-var47 = ((short int (*)(val*, val*))(var46->class->vft[COLOR_abstract_collection__MapRead__has_key]))(var46, var_short_opt) /* has_key on <var46:Map[String, Option]>*/;
-if (var47){
-var48 = self->attrs[COLOR_opts__OptionContext___optmap].val; /* _optmap on <self:OptionContext> */
-if (var48 == NULL) {
+var48 = ((short int (*)(val*, val*))(var47->class->vft[COLOR_abstract_collection__MapRead__has_key]))(var47, var_short_opt) /* has_key on <var47:Map[String, Option]>*/;
+if (var48){
+var49 = self->attrs[COLOR_opts__OptionContext___optmap].val; /* _optmap on <self:OptionContext> */
+if (var49 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _optmap");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 278);
-exit(1);
+show_backtrace(1);
 }
-var49 = ((val* (*)(val*, val*))(var48->class->vft[COLOR_abstract_collection__MapRead___91d_93d]))(var48, var_short_opt) /* [] on <var48:Map[String, Option]>*/;
-var_option = var49;
+var50 = ((val* (*)(val*, val*))(var49->class->vft[COLOR_abstract_collection__MapRead___91d_93d]))(var49, var_short_opt) /* [] on <var49:Map[String, Option]>*/;
+var_option = var50;
 /* <var_option:Option> isa OptionParameter */
-cltype51 = type_opts__OptionParameter.color;
-idtype52 = type_opts__OptionParameter.id;
-if(cltype51 >= var_option->type->table_size) {
-var50 = 0;
+cltype52 = type_opts__OptionParameter.color;
+idtype53 = type_opts__OptionParameter.id;
+if(cltype52 >= var_option->type->table_size) {
+var51 = 0;
 } else {
-var50 = var_option->type->type_table[cltype51] == idtype52;
+var51 = var_option->type->type_table[cltype52] == idtype53;
 }
-if (var50){
+if (var51){
 ((void (*)(val*))(var_it->class->vft[COLOR_abstract_collection__Iterator__next]))(var_it) /* next on <var_it:Iterator[String]>*/;
-var53 = 1;
-var_next_called = var53;
+var54 = 1;
+var_next_called = var54;
 } else {
 }
 ((void (*)(val*, val*))(var_option->class->vft[COLOR_opts__Option__read_param]))(var_option, var_it) /* read_param on <var_option:Option>*/;
@@ -2038,115 +2031,114 @@ CONTINUE_label: (void)0;
 ((void (*)(val*))(var33->class->vft[COLOR_abstract_collection__Iterator__next]))(var33) /* next on <var33:Iterator[nullable Object]>*/;
 }
 BREAK_label: (void)0;
-var54 = !var_next_called;
-if (var54){
+var55 = !var_next_called;
+if (var55){
 ((void (*)(val*))(var_it->class->vft[COLOR_abstract_collection__Iterator__next]))(var_it) /* next on <var_it:Iterator[String]>*/;
 } else {
 }
 } else {
-var55 = self->attrs[COLOR_opts__OptionContext___optmap].val; /* _optmap on <self:OptionContext> */
-if (var55 == NULL) {
+var56 = self->attrs[COLOR_opts__OptionContext___optmap].val; /* _optmap on <self:OptionContext> */
+if (var56 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _optmap");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 288);
-exit(1);
+show_backtrace(1);
 }
-var56 = ((short int (*)(val*, val*))(var55->class->vft[COLOR_abstract_collection__MapRead__has_key]))(var55, var_str) /* has_key on <var55:Map[String, Option]>*/;
-if (var56){
-var57 = self->attrs[COLOR_opts__OptionContext___optmap].val; /* _optmap on <self:OptionContext> */
-if (var57 == NULL) {
+var57 = ((short int (*)(val*, val*))(var56->class->vft[COLOR_abstract_collection__MapRead__has_key]))(var56, var_str) /* has_key on <var56:Map[String, Option]>*/;
+if (var57){
+var58 = self->attrs[COLOR_opts__OptionContext___optmap].val; /* _optmap on <self:OptionContext> */
+if (var58 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _optmap");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 289);
-exit(1);
+show_backtrace(1);
 }
-var58 = ((val* (*)(val*, val*))(var57->class->vft[COLOR_abstract_collection__MapRead___91d_93d]))(var57, var_str) /* [] on <var57:Map[String, Option]>*/;
-var_opt = var58;
+var59 = ((val* (*)(val*, val*))(var58->class->vft[COLOR_abstract_collection__MapRead___91d_93d]))(var58, var_str) /* [] on <var58:Map[String, Option]>*/;
+var_opt = var59;
 ((void (*)(val*))(var_it->class->vft[COLOR_abstract_collection__Iterator__next]))(var_it) /* next on <var_it:Iterator[String]>*/;
 ((void (*)(val*, val*))(var_opt->class->vft[COLOR_opts__Option__read_param]))(var_opt, var_it) /* read_param on <var_opt:Option>*/;
 } else {
-var59 = ((val* (*)(val*))(var_it->class->vft[COLOR_abstract_collection__Iterator__item]))(var_it) /* item on <var_it:Iterator[String]>*/;
-((void (*)(val*, val*))(var_rest->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var_rest, var59) /* add on <var_rest:Array[String]>*/;
+var60 = ((val* (*)(val*))(var_it->class->vft[COLOR_abstract_collection__Iterator__item]))(var_it) /* item on <var_it:Iterator[String]>*/;
+((void (*)(val*, val*))(var_rest->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var_rest, var60) /* add on <var_rest:Array[String]>*/;
 ((void (*)(val*))(var_it->class->vft[COLOR_abstract_collection__Iterator__next]))(var_it) /* next on <var_it:Iterator[String]>*/;
 }
 }
 }
-CONTINUE_label60: (void)0;
+CONTINUE_label61: (void)0;
 }
-BREAK_label60: (void)0;
-var61 = self->attrs[COLOR_opts__OptionContext___options].val; /* _options on <self:OptionContext> */
-if (var61 == NULL) {
+BREAK_label61: (void)0;
+var62 = self->attrs[COLOR_opts__OptionContext___options].val; /* _options on <self:OptionContext> */
+if (var62 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _options");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 300);
-exit(1);
+show_backtrace(1);
 }
-var62 = ((val* (*)(val*))(var61->class->vft[COLOR_abstract_collection__Collection__iterator]))(var61) /* iterator on <var61:Array[Option]>*/;
+var63 = ((val* (*)(val*))(var62->class->vft[COLOR_abstract_collection__Collection__iterator]))(var62) /* iterator on <var62:Array[Option]>*/;
 for(;;) {
-var63 = ((short int (*)(val*))(var62->class->vft[COLOR_abstract_collection__Iterator__is_ok]))(var62) /* is_ok on <var62:Iterator[nullable Object]>*/;
-if(!var63) break;
-var64 = ((val* (*)(val*))(var62->class->vft[COLOR_abstract_collection__Iterator__item]))(var62) /* item on <var62:Iterator[nullable Object]>*/;
-var_opt65 = var64;
-var67 = ((short int (*)(val*))(var_opt65->class->vft[COLOR_opts__Option__mandatory]))(var_opt65) /* mandatory on <var_opt65:Option>*/;
-var_68 = var67;
-if (var67){
-var69 = ((short int (*)(val*))(var_opt65->class->vft[COLOR_opts__Option__read]))(var_opt65) /* read on <var_opt65:Option>*/;
-var70 = !var69;
-var66 = var70;
+var64 = ((short int (*)(val*))(var63->class->vft[COLOR_abstract_collection__Iterator__is_ok]))(var63) /* is_ok on <var63:Iterator[nullable Object]>*/;
+if(!var64) break;
+var65 = ((val* (*)(val*))(var63->class->vft[COLOR_abstract_collection__Iterator__item]))(var63) /* item on <var63:Iterator[nullable Object]>*/;
+var_opt66 = var65;
+var68 = ((short int (*)(val*))(var_opt66->class->vft[COLOR_opts__Option__mandatory]))(var_opt66) /* mandatory on <var_opt66:Option>*/;
+var_69 = var68;
+if (var68){
+var70 = ((short int (*)(val*))(var_opt66->class->vft[COLOR_opts__Option__read]))(var_opt66) /* read on <var_opt66:Option>*/;
+var71 = !var70;
+var67 = var71;
 } else {
-var66 = var_68;
+var67 = var_69;
 }
-if (var66){
-var71 = self->attrs[COLOR_opts__OptionContext___errors].val; /* _errors on <self:OptionContext> */
-if (var71 == NULL) {
+if (var67){
+var72 = self->attrs[COLOR_opts__OptionContext___errors].val; /* _errors on <self:OptionContext> */
+if (var72 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _errors");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 302);
-exit(1);
+show_backtrace(1);
 }
-if (varonce72) {
-var73 = varonce72;
+if (varonce73) {
+var74 = varonce73;
 } else {
-var74 = "Mandatory option ";
-var75 = 17;
-var76 = string__NativeString__to_s_with_length(var74, var75);
-var73 = var76;
-varonce72 = var73;
-}
-var77 = ((val* (*)(val*))(var_opt65->class->vft[COLOR_opts__Option__names]))(var_opt65) /* names on <var_opt65:Option>*/;
-if (varonce78) {
-var79 = varonce78;
+var75 = "Mandatory option ";
+var76 = 17;
+var77 = string__NativeString__to_s_with_length(var75, var76);
+var74 = var77;
+varonce73 = var74;
+}
+var78 = ((val* (*)(val*))(var_opt66->class->vft[COLOR_opts__Option__names]))(var_opt66) /* names on <var_opt66:Option>*/;
+if (varonce79) {
+var80 = varonce79;
 } else {
-var80 = ", ";
-var81 = 2;
-var82 = string__NativeString__to_s_with_length(var80, var81);
-var79 = var82;
-varonce78 = var79;
-}
-var83 = ((val* (*)(val*, val*))(var77->class->vft[COLOR_string__Collection__join]))(var77, var79) /* join on <var77:Array[String]>*/;
-if (varonce84) {
-var85 = varonce84;
+var81 = ", ";
+var82 = 2;
+var83 = string__NativeString__to_s_with_length(var81, var82);
+var80 = var83;
+varonce79 = var80;
+}
+var84 = ((val* (*)(val*, val*))(var78->class->vft[COLOR_string__Collection__join]))(var78, var80) /* join on <var78:Array[String]>*/;
+if (varonce85) {
+var86 = varonce85;
 } else {
-var86 = " not found.";
-var87 = 11;
-var88 = string__NativeString__to_s_with_length(var86, var87);
-var85 = var88;
-varonce84 = var85;
-}
-var89 = NEW_array__Array(&type_array__Arraykernel__Object);
-{ /* var89 = array_instance Array[Object] */
-var90 = 3;
-var91 = NEW_array__NativeArray(var90, &type_array__NativeArraykernel__Object);
-((struct instance_array__NativeArray*)var91)->values[0] = (val*) var73;
-((struct instance_array__NativeArray*)var91)->values[1] = (val*) var83;
-((struct instance_array__NativeArray*)var91)->values[2] = (val*) var85;
-((void (*)(val*, val*, long))(var89->class->vft[COLOR_array__Array__with_native]))(var89, var91, var90) /* with_native on <var89:Array[Object]>*/;
-CHECK_NEW_array__Array(var89);
-}
-var92 = ((val* (*)(val*))(var89->class->vft[COLOR_string__Object__to_s]))(var89) /* to_s on <var89:Array[Object]>*/;
-((void (*)(val*, val*))(var71->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var71, var92) /* add on <var71:Array[String]>*/;
+var87 = " not found.";
+var88 = 11;
+var89 = string__NativeString__to_s_with_length(var87, var88);
+var86 = var89;
+varonce85 = var86;
+}
+var90 = NEW_array__Array(&type_array__Arraykernel__Object);
+{ /* var90 = array_instance Array[Object] */
+var91 = 3;
+var92 = NEW_array__NativeArray(var91, &type_array__NativeArraykernel__Object);
+((struct instance_array__NativeArray*)var92)->values[0] = (val*) var74;
+((struct instance_array__NativeArray*)var92)->values[1] = (val*) var84;
+((struct instance_array__NativeArray*)var92)->values[2] = (val*) var86;
+((void (*)(val*, val*, long))(var90->class->vft[COLOR_array__Array__with_native]))(var90, var92, var91) /* with_native on <var90:Array[Object]>*/;
+}
+var93 = ((val* (*)(val*))(var90->class->vft[COLOR_string__Object__to_s]))(var90) /* to_s on <var90:Array[Object]>*/;
+((void (*)(val*, val*))(var72->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var72, var93) /* add on <var72:Array[String]>*/;
 } else {
 }
-CONTINUE_label93: (void)0;
-((void (*)(val*))(var62->class->vft[COLOR_abstract_collection__Iterator__next]))(var62) /* next on <var62:Iterator[nullable Object]>*/;
+CONTINUE_label94: (void)0;
+((void (*)(val*))(var63->class->vft[COLOR_abstract_collection__Iterator__next]))(var63) /* next on <var63:Iterator[nullable Object]>*/;
 }
-BREAK_label93: (void)0;
+BREAK_label94: (void)0;
 RET_LABEL:;
 }
 /* method opts#OptionContext#parse_intern for (self: Object, Iterator[String]) */
@@ -2173,7 +2165,7 @@ var3 = self->attrs[COLOR_opts__OptionContext___options].val; /* _options on <sel
 if (var3 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _options");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 310);
-exit(1);
+show_backtrace(1);
 }
 ((void (*)(val*, val*))(var3->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var3, var_opt) /* add on <var3:Array[Option]>*/;
 CONTINUE_label: (void)0;
@@ -2195,19 +2187,15 @@ val* var2 /* : Array[String] */;
 val* var3 /* : Array[String] */;
 var = NEW_array__Array(&type_array__Arrayopts__Option);
 ((void (*)(val*))(var->class->vft[COLOR_array__Array__init]))(var) /* init on <var:Array[Option]>*/;
-CHECK_NEW_array__Array(var);
 self->attrs[COLOR_opts__OptionContext___options].val = var; /* _options on <self:OptionContext> */
 var1 = NEW_hash_collection__HashMap(&type_hash_collection__HashMapstring__Stringopts__Option);
 ((void (*)(val*))(var1->class->vft[COLOR_hash_collection__HashMap__init]))(var1) /* init on <var1:HashMap[String, Option]>*/;
-CHECK_NEW_hash_collection__HashMap(var1);
 self->attrs[COLOR_opts__OptionContext___optmap].val = var1; /* _optmap on <self:OptionContext> */
 var2 = NEW_array__Array(&type_array__Arraystring__String);
 ((void (*)(val*))(var2->class->vft[COLOR_array__Array__init]))(var2) /* init on <var2:Array[String]>*/;
-CHECK_NEW_array__Array(var2);
 self->attrs[COLOR_opts__OptionContext___rest].val = var2; /* _rest on <self:OptionContext> */
 var3 = NEW_array__Array(&type_array__Arraystring__String);
 ((void (*)(val*))(var3->class->vft[COLOR_array__Array__init]))(var3) /* init on <var3:Array[String]>*/;
-CHECK_NEW_array__Array(var3);
 self->attrs[COLOR_opts__OptionContext___errors].val = var3; /* _errors on <self:OptionContext> */
 RET_LABEL:;
 }
@@ -2233,7 +2221,7 @@ var = self->attrs[COLOR_opts__OptionContext___options].val; /* _options on <self
 if (var == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _options");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 324);
-exit(1);
+show_backtrace(1);
 }
 var1 = ((val* (*)(val*))(var->class->vft[COLOR_abstract_collection__Collection__iterator]))(var) /* iterator on <var:Array[Option]>*/;
 for(;;) {
@@ -2252,7 +2240,7 @@ var8 = self->attrs[COLOR_opts__OptionContext___optmap].val; /* _optmap on <self:
 if (var8 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _optmap");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 326);
-exit(1);
+show_backtrace(1);
 }
 ((void (*)(val*, val*, val*))(var8->class->vft[COLOR_abstract_collection__Map___91d_93d_61d]))(var8, var_n, var_o) /* []= on <var8:Map[String, Option]>*/;
 CONTINUE_label: (void)0;
@@ -2288,20 +2276,19 @@ val* var10 /* : nullable Object */;
 val* var_e /* var e: String */;
 var1 = NEW_array__Array(&type_array__Arraystring__String);
 ((void (*)(val*))(var1->class->vft[COLOR_array__Array__init]))(var1) /* init on <var1:Array[String]>*/;
-CHECK_NEW_array__Array(var1);
 var_errors = var1;
 var2 = self->attrs[COLOR_opts__OptionContext___errors].val; /* _errors on <self:OptionContext> */
 if (var2 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _errors");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 335);
-exit(1);
+show_backtrace(1);
 }
 ((void (*)(val*, val*))(var_errors->class->vft[COLOR_abstract_collection__SimpleCollection__add_all]))(var_errors, var2) /* add_all on <var_errors:Array[String]>*/;
 var3 = self->attrs[COLOR_opts__OptionContext___options].val; /* _options on <self:OptionContext> */
 if (var3 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute _options");
 fprintf(stderr, " (%s:%d)\n", "lib/opts.nit", 337);
-exit(1);
+show_backtrace(1);
 }
 var4 = ((val* (*)(val*))(var3->class->vft[COLOR_abstract_collection__Collection__iterator]))(var3) /* iterator on <var3:Array[Option]>*/;
 for(;;) {