typecheck: diagnose missing TYPE OF AS

README.md

@@ -159,6 +159,12 @@ If `IS` is present but the expression is missing, Claro points out that the expr
 CHECK TYPE needs an expression before IS. Try: CHECK TYPE score IS NUMBER.
 ```
 
+`TYPE OF` also explains when the result variable is missing its `AS` keyword:
+
+```text
+TYPE OF needs AS. Try: TYPE OF score AS kind.
+```
+
 If the learner writes `IS` but leaves out the expected type, Claro names the missing piece and shows a complete example:
 
 ```text

docs/CURRENT_STATUS.md

@@ -57,6 +57,7 @@ Ready now:
 - `CHECK TYPE` explains when `IS` is present but the expression is missing, for example `CHECK TYPE IS NUMBER` reports `CHECK TYPE needs an expression before IS. Try: CHECK TYPE score IS NUMBER.`
 - `CHECK TYPE` rejects extra words after a valid expected type with a direct repair hint, so `CHECK TYPE score IS NUMBER TEXT` explains that only one type belongs in the check
 - `CHECK TYPE` rejects unknown expected type names with a beginner-facing list of supported types
+- `TYPE OF` reports a direct repair hint when the learner forgets `AS`, for example `TYPE OF score` suggests `TYPE OF score AS kind`
 - typed list/map checks through `claro typecheck`, including a nested `LIST OF MAP` insertion example
 - simple function and object-method return checks with `TEACH name ... RETURNS TYPE`, including learner-facing diagnostics for unknown declared return types, mismatched or not-yet-inferable `RETURN` expressions (including method-specific diagnostics naming the class and method, with modern and compatibility method coverage), empty `RETURN` statements, declarations that contain no `RETURN`, and declarations whose only return is inside an incomplete conditional; `RETURNS` is case-insensitive like other Claro keywords and has positive coverage in both modern and compatibility function forms, including lowercase compatibility declarations and lowercase compatibility method declarations, plus a lowercase compatibility-method mismatch diagnostic; `CHECK TYPE` parameter metadata also informs arithmetic return-expression checking, including method return expressions; positive function-return coverage includes numeric multiplication; compatibility methods now have dedicated positive numeric addition, subtraction, division, and multiplication return fixtures plus compatibility addition, subtraction, division, and multiplication diagnostic fixtures; NUMBER return diagnostics name a known TEXT operand and arithmetic operation instead of hiding the cause behind a generic mismatch, with focused addition, subtraction, multiplication, and division coverage for functions and methods; typed methods can also return class-declared fields by simple name, with positive and mismatch coverage in both modern and compatibility method syntax
 - a narrow function/method argument check: `CHECK TYPE parameter IS TYPE` inside a function or simple object method lets `claro typecheck` accept correct checked calls, catch mismatched `DO`, `CALL ... WITH`, `DO object.method ...`, and compatibility `CALL object.method WITH ...` arguments, including checked methods that appear after another method in the same class, report missing checked function and method arguments, report missing unchecked arguments for simple functions and simple object methods in both modern `DO` and compatibility `CALL ... WITH` forms, treat empty compatibility calls such as `CALL greet WITH` and `CALL player.rename WITH` as missing-argument mistakes, catch extra arguments to simple functions and checked methods even when the checked method appears after another method in the same class, catch modern `DO` and compatibility `CALL ... WITH` calls to undeclared simple functions, explain when `DO object.method ...` or compatibility `CALL object.method ...` happens before the object is created with `NEW` even if the method name is also wrong, and catch modern plus compatibility calls to undeclared object methods with a class-specific `TEACH` hint

docs/ROADMAP.md

@@ -78,6 +78,7 @@ Keep declared return types honest: `claro typecheck` now reports friendly diagno
 8q.2. Keep `CHECK TYPE` declarations unambiguous: extra words after a valid expected type now get a direct repair hint instead of being reported as an unknown type.
 8q.3. Keep `CHECK TYPE` declarations complete: a bare `CHECK TYPE` now explains that the expression, `IS`, and expected type are all required, with a complete repair example.
 8q.4. Keep `CHECK TYPE` declarations ordered: `CHECK TYPE IS NUMBER` now explains that an expression belongs before `IS`, with a complete repair example.
+8q.5. Keep `TYPE OF` declarations understandable: a missing `AS` now gets a direct repair hint with a complete `TYPE OF score AS kind` example.
 
 ### 1. Strong static types
 

src/claro.c

@@ -637,7 +637,7 @@ else if(!strcmp(up,"IF")){ if(in_teach){ if(nested_blocks<64){ branch_returned[n
   else if(!strcmp(up,"PUT")){ const char *key=find_word_ci(t,"KEY"), *val=find_word_ci(t,"VALUE"); if(key&&val){ char *name=substr(t+3,key); char *expr=xstrdup(trim_inplace((char*)val+5)); char *nt=trim_inplace(name); const char *maptype=type_env_get(types,nt); const char *need=container_member_type(maptype,"MAP"); const char *got=simple_expr_type(types,expr); if(need&&got&&!type_words_match(need,got)){ printf("%s:%d: Type mismatch for map %s: expected %s value, but this value looks like %s.\n",path,line_no,nt,need,got); errs++; } free(name); free(expr); } }
   else if(!strcmp(up,"ASK")){ const char *as=find_word_ci(t,"AS"); char *name=NULL,*type=NULL; if(as){ const char *pcur=as+2; name=unquote_token(&pcur); { char *rest=xstrdup(trim_inplace((char*)pcur)); if(claro_is_type_word(rest)) type=rest; else free(rest); } } else { const char *pcur=t+3; char *prompt=unquote_token(&pcur); free(prompt); name=unquote_token(&pcur); { char *rest=xstrdup(trim_inplace((char*)pcur)); if(claro_is_type_word(rest)) type=rest; else free(rest); } } if(name&&*trim_inplace(name)) type_env_set(&types,trim_inplace(name),type?type:"TEXT"); free(name); free(type); }
   else if(!strcmp(up,"IMPORT")){ const char *as=find_word_ci(t,"AS"); if(as){ const char *pcur=as+2; char *alias=unquote_token(&pcur); if(alias&&*trim_inplace(alias)) type_env_set(&types,trim_inplace(alias),"MODULE"); free(alias); } }
-  else if(!strcmp(up,"TYPE")&&starts_ci(t,"TYPE OF")){ char *name=check_var_after_as(t); if(name){ type_env_set(&types,name,"TEXT"); free(name); } }
+  else if(!strcmp(up,"TYPE")&&starts_ci(t,"TYPE OF")){ const char *as=find_word_ci(t,"AS"); if(!as){ printf("%s:%d: TYPE OF needs AS. Try: TYPE OF score AS kind.\n",path,line_no); errs++; } else { char *name=check_var_after_as(t); if(name){ type_env_set(&types,name,"TEXT"); free(name); } } }
   else if(!strcmp(up,"NEW")){ const char *as=find_word_ci(t,"AS"); char *name=NULL; char *cls=NULL; char *extra=NULL; char objtype[256]; if(as){ const char *pcur=as+2; cls=substr(t+3,as); name=unquote_token(&pcur); extra=xstrdup(trim_inplace((char *)pcur)); } else { const char *pcur=t+3; cls=unquote_token(&pcur); name=unquote_token(&pcur); extra=xstrdup(trim_inplace((char *)pcur)); } snprintf(objtype,sizeof(objtype),"OBJECT:%s",trim_inplace(cls)); if(name&&*trim_inplace(name)){ TypeFieldCheck *fc; char fullname[256]; char *nt=trim_inplace(name); char *ct=trim_inplace(cls); int duplicate=0,class_known=0,oi,ci; if(extra&&*extra){ printf("%s:%d: NEW %s has extra text after object name %s. Keep only the class and object names.\n",path,line_no,ct,nt); errs++; } for(ci=0;ci<declared_class_count;ci++) if(ci_eq(declared_classes[ci],ct)){ class_known=1; break; } if(declared_class_count>0&&!class_known){ printf("%s:%d: Class %s is not known yet. Check the class name or declare CLASS %s before creating %s.\n",path,line_no,ct,ct,nt); errs++; } for(oi=0;oi<declared_object_count;oi++) if(ci_eq(declared_objects[oi],nt)){ duplicate=1; break; } if(duplicate){ printf("%s:%d: Object %s is created more than once. Give each object a different name.\n",path,line_no,nt); errs++; } else if(declared_object_count<128) snprintf(declared_objects[declared_object_count++],sizeof(declared_objects[0]),"%s",nt); type_env_set(&types,nt,objtype); for(fc=field_checks;fc;fc=fc->next){ if(ci_eq(fc->cls,ct)){ snprintf(fullname,sizeof(fullname),"%s.%s",nt,fc->field); type_env_set(&types,fullname,fc->type); } } } else if(cls&&*trim_inplace(cls)){ printf("%s:%d: NEW %s needs an object name. Add a name after the class, such as NEW %s player.\n",path,line_no,trim_inplace(cls),trim_inplace(cls)); errs++; } else { printf("%s:%d: NEW needs a class name. Add a class and object name, such as NEW Player player.\n",path,line_no); errs++; } free(cls); free(name); free(extra); }
   else if((!strcmp(up,"DO")&&!find_word_ci(t,"TIMES"))||!strcmp(up,"CALL")){ char *fname=NULL; char **parts=NULL; int ac=0,i,is_method=0; char lookup[256],display[256]; if(!strcmp(up,"DO")){ const char *pcur=t+2; fname=unquote_token(&pcur); if(*trim_inplace((char*)pcur)) ac=split_args(pcur,&parts); } else { char *rest=t+4; const char *with=find_word_ci(rest,"WITH"); fname=with?substr(rest,with):xstrdup(rest); if(with&&*trim_inplace((char*)with+4)) ac=split_args(with+4,&parts); } snprintf(lookup,sizeof(lookup),"%s",trim_inplace(fname)); snprintf(display,sizeof(display),"%s",lookup); { char *dot=strchr(lookup,'.'); if(dot){ char objname[128]; const char *objtype; snprintf(objname,sizeof(objname),"%.*s",(int)(dot-lookup),lookup); objtype=type_env_get(types,objname); if(objtype&&starts_ci(objtype,"OBJECT:")){ char method[128]; const char *cls=objtype+7; snprintf(method,sizeof(method),"%s",dot+1); if(!type_method_check_for(method_checks,cls,method)){ printf("%s:%d: Object %s has no method %s. Check the method name or add TEACH %s inside CLASS %s.\n",path,line_no,cls,method,method,cls); errs++; } snprintf(lookup,sizeof(lookup),"%s.%s",cls,method); snprintf(display,sizeof(display),"%s",lookup); is_method=1; }
        else if(!objtype||(!starts_ci(objtype,"MODULE")&&(!strcmp(up,"DO")||type_method_name_exists(method_checks,dot+1)))){ printf("%s:%d: Object %s is not known yet. Create it with NEW ClassName %s before calling %s.\n",path,line_no,objname,objname,lookup); errs++; } } } for(i=0;i<ac;i++){ const char *param=NULL; const char *need=type_param_check_for(param_checks,lookup,i,&param); const char *got=simple_expr_type(types,parts[i]); if(need&&got&&!type_words_match(need,got)){ printf("%s:%d: Type mismatch for %s %s: parameter %s needs %s, but this argument looks like %s.\n",path,line_no,is_method?"method":"function",display,param?param:"argument",need,got); errs++; } } { TypeParamCheck *pc=param_checks; while(pc){ if(ci_eq(pc->func,lookup)&&pc->pos>=ac){ printf("%s:%d: %s %s needs argument %s as %s, but this call does not provide it.\n",path,line_no,is_method?"Method":"Function",display,pc->param,pc->type); errs++; } pc=pc->next; } } { int expected=type_arity_check_for(arity_checks,lookup); if(expected>=0&&ac>expected){ printf("%s:%d: %s %s only accepts %d %s, but this call gives %d. Remove the extra %s.\n",path,line_no,is_method?"Method":"Function",display,expected,expected==1?"argument":"arguments",ac,ac-expected==1?"argument":"arguments"); errs++; } else if(expected>=0&&ac<expected){ int has_checked_missing=0; TypeParamCheck *mpc=param_checks; while(mpc){ if(ci_eq(mpc->func,lookup)&&mpc->pos>=ac){ has_checked_missing=1; break; } mpc=mpc->next; } if(!has_checked_missing){ printf("%s:%d: %s %s needs %d %s, but this call gives %d. Add the missing %s.\n",path,line_no,is_method?"Method":"Function",display,expected,expected==1?"argument":"arguments",ac,expected-ac==1?"argument":"arguments"); errs++; } } else if((!strcmp(up,"DO")||!strcmp(up,"CALL"))&&!is_method&&!strchr(lookup,'.')&&expected<0){ printf("%s:%d: Function %s is not known yet. Check the function name or add TEACH %s before calling it.\n",path,line_no,lookup,lookup); errs++; } } free(fname); }

tests/typecheck_missing_type_of_as_bad.claro

@@ -0,0 +1,2 @@
+SET score NUMBER 10
+TYPE OF score

tools/validate_typecheck_diagnostics.py

@@ -302,6 +302,9 @@ EXPECTED = {
     "tests/typecheck_missing_expression_with_is_bad.claro": [
         "tests/typecheck_missing_expression_with_is_bad.claro:1: CHECK TYPE needs an expression before IS. Try: CHECK TYPE score IS NUMBER.",
     ],
+    "tests/typecheck_missing_type_of_as_bad.claro": [
+        "tests/typecheck_missing_type_of_as_bad.claro:2: TYPE OF needs AS. Try: TYPE OF score AS kind.",
+    ],
     "tests/typecheck_extra_check_type_tokens_bad.claro": [
         "tests/typecheck_extra_check_type_tokens_bad.claro:2: CHECK TYPE score has extra text after type NUMBER. Keep only the expression, IS, and one type.",
     ],