Do not say "function" in method error messages (#611)

compiler/ast.jou

@@ -459,7 +459,6 @@ class AstCall:
             free(self->method_call_self)
 
     # Useful for formatting error messages, but not much else.
-    # TODO: use this
     def function_or_method(self) -> byte*:
         if self->method_call_self == NULL:
             return "function"

compiler/parser.jou

@@ -318,10 +318,11 @@ class Parser:
         return result
 
     def parse_function_or_method_signature(self, is_method: bool) -> AstSignature:
-        # TODO: change error messages to say method, when it is a method (#243)
-        used_self: bool = False
         if self->tokens->kind != TokenKind.Name:
-            self->tokens->fail_expected_got("a function name")
+            if is_method:
+                self->tokens->fail_expected_got("a method name")
+            else:
+                self->tokens->fail_expected_got("a function name")
 
         result = AstSignature{
             name_location = self->tokens->location,
@@ -330,9 +331,10 @@ class Parser:
         self->tokens++
 
         if not self->tokens->is_operator("("):
-            self->tokens->fail_expected_got("a '(' to denote the start of function arguments")
+            self->tokens->fail_expected_got("a '(' to denote the start of arguments")
         self->tokens++
 
+        used_self = False
         while not self->tokens->is_operator(")"):
             if result.takes_varargs:
                 fail(self->tokens->location, "if '...' is used, it must be the last parameter")
@@ -389,7 +391,10 @@ class Parser:
 
         # Special case for common typo:   def foo():
         if self->tokens->is_operator(":"):
-            fail(self->tokens->location, "return type must be specified with '->', or with '-> None' if the function doesn't return anything")
+            if is_method:
+                fail(self->tokens->location, "return type must be specified with '->', or with '-> None' if the method doesn't return anything")
+            else:
+                fail(self->tokens->location, "return type must be specified with '->', or with '-> None' if the function doesn't return anything")
         if not self->tokens->is_operator("->"):
             self->tokens->fail_expected_got("a '->'")
         self->tokens++
@@ -423,7 +428,7 @@ class Parser:
         return result
 
     def parse_instantiation(self) -> AstInstantiation:
-        assert self->tokens->kind == TokenKind.Name  # must be checked when calling this function
+        assert self->tokens->kind == TokenKind.Name
         result = AstInstantiation{class_name_location = self->tokens->location, class_name = self->tokens->short_string}
         self->tokens++
         assert self->tokens->is_operator("{")

compiler/typecheck/step2_populate_types.jou

@@ -44,13 +44,15 @@ def handle_global_var(ft: FileTypes*, vardecl: AstNameTypeValue*, defined_here:
 
 
 def handle_signature(ft: FileTypes*, astsig: AstSignature*, self_class: Type*) -> Signature:
+    if self_class == NULL:
+        function_or_method = "function"
+    else:
+        function_or_method = "method"
+
     msg: byte[500]
 
     if ft->find_function_or_method(self_class, astsig->name) != NULL:
-        if self_class != NULL:
-            snprintf(msg, sizeof(msg), "a method named '%s' already exists", astsig->name)
-        else:
-            snprintf(msg, sizeof(msg), "a function named '%s' already exists", astsig->name)
+        snprintf(msg, sizeof(msg), "a %s named '%s' already exists", function_or_method, astsig->name)
         fail(astsig->name_location, msg)
 
     sig = Signature{nargs = astsig->nargs, takes_varargs = astsig->takes_varargs}
@@ -85,7 +87,12 @@ def handle_signature(ft: FileTypes*, astsig: AstSignature*, self_class: Type*) -
     if astsig->return_type.is_none() or astsig->return_type.is_noreturn():
         sig.returntype = NULL
     elif astsig->return_type.is_void():
-        fail(astsig->return_type.location, "void is not a valid return type, use '-> None' if the function does not return a value")
+        snprintf(
+            msg, sizeof(msg),
+            "void is not a valid return type, use '-> None' if the %s does not return a value",
+            function_or_method,
+        )
+        fail(astsig->return_type.location, msg)
     else:
         sig.returntype = type_from_ast(ft, &astsig->return_type)
 

compiler/typecheck/step3_function_and_method_bodies.jou

@@ -334,10 +334,7 @@ def typecheck_expression_not_void(ft: FileTypes*, expr: AstExpression*) -> Type*
     assert expr->kind == AstExpressionKind.Call
 
     msg: byte[500]
-    if expr->call.method_call_self == NULL:
-        snprintf(msg, sizeof(msg), "function '%s' does not return a value", expr->call.name)
-    else:
-        snprintf(msg, sizeof(msg), "method '%s' does not return a value", expr->call.name)
+    snprintf(msg, sizeof(msg), "%s '%s' does not return a value", expr->call.function_or_method(), expr->call.name)
     fail(expr->location, msg)
 
 
@@ -1128,30 +1125,37 @@ def typecheck_statement(ft: FileTypes*, stmt: AstStatement*) -> None:
             fail(stmt->location, msg)
 
     elif stmt->kind == AstStatementKind.Return:
+        function_or_method = ft->current_fom_types->signature.function_or_method()
+
         if ft->current_fom_types->signature.is_noreturn:
-            snprintf(msg, sizeof(msg),
-                "function '%s' cannot return because it was defined with '-> noreturn'",
-                ft->current_fom_types->signature.name)
+            snprintf(
+                msg, sizeof(msg),
+                "%s '%s' cannot return because it was defined with '-> noreturn'",
+                function_or_method, ft->current_fom_types->signature.name,
+            )
             fail(stmt->location, msg)
 
         return_type = ft->current_fom_types->signature.returntype
 
         if stmt->return_value != NULL and return_type == NULL:
-            snprintf(msg, sizeof(msg), "function '%s' cannot return a value because it was defined with '-> None'",
-                ft->current_fom_types->signature.name)
+            snprintf(
+                msg, sizeof(msg), "%s '%s' cannot return a value because it was defined with '-> None'",
+                function_or_method, ft->current_fom_types->signature.name,
+            )
             fail(stmt->location, msg)
 
         if return_type != NULL and stmt->return_value == NULL:
             snprintf(msg, sizeof(msg),
-                "a return value is needed, because the return type of function '%s' is %s",
+                "a return value is needed, because the return type of %s '%s' is %s",
+                function_or_method,
                 ft->current_fom_types->signature.name,
                 ft->current_fom_types->signature.returntype->name)
             fail(stmt->location, msg)
 
         if stmt->return_value != NULL:
             snprintf(msg, sizeof msg,
-                "attempting to return a value of type <from> from function '%s' defined with '-> <to>'",
-                ft->current_fom_types->signature.name)
+                "attempting to return a value of type <from> from %s '%s' defined with '-> <to>'",
+                function_or_method, ft->current_fom_types->signature.name)
             typecheck_expression_with_implicit_cast(
                 ft, stmt->return_value, ft->find_local_var("return")->type, msg)
 

compiler/types.jou

@@ -277,6 +277,13 @@ class Signature:
             assert False
         return NULL
 
+    # Useful for error messages, not much else.
+    def function_or_method(self) -> byte*:
+        if self->get_self_class() == NULL:
+            return "function"
+        else:
+            return "method"
+
     def to_string(self, include_return_type: bool, include_self: bool) -> byte*:
         result = strdup(self->name)
         assert result != NULL

tests/other_errors/missing_value_in_return_method.jou

@@ -0,0 +1,3 @@
+class Foo:
+    def bar(self) -> int:
+        return  # Error: a return value is needed, because the return type of method 'bar' is int

tests/other_errors/noreturn_but_return_with_value_method.jou

@@ -0,0 +1,3 @@
+class Foo:
+    def bar(self) -> noreturn:
+        return 1  # Error: method 'bar' cannot return because it was defined with '-> noreturn'

tests/other_errors/return_void_method.jou

@@ -0,0 +1,3 @@
+class Foo:
+    def foo(self) -> void:  # Error: void is not a valid return type, use '-> None' if the method does not return a value
+        pass

tests/other_errors/unexpected_return_value_method.jou

@@ -0,0 +1,3 @@
+class Foo:
+    def f(self) -> None:
+        return 123  # Error: method 'f' cannot return a value because it was defined with '-> None'

tests/syntax_error/bad_method_name_after_def.jou

@@ -0,0 +1,3 @@
+class Foo:
+    def 69(self) -> None:  # Error: expected a method name, got an integer
+        return

tests/syntax_error/missing_args_function.jou

@@ -0,0 +1,2 @@
+def foo:  # Error: expected a '(' to denote the start of arguments, got ':'
+    return

tests/syntax_error/missing_args_method.jou

@@ -0,0 +1,3 @@
+class Foo:
+    def bar:  # Error: expected a '(' to denote the start of arguments, got ':'
+        return

tests/syntax_error/missing_return_type_method.jou

@@ -0,0 +1,3 @@
+class Foo:
+    def bar(self):  # Error: return type must be specified with '->', or with '-> None' if the method doesn't return anything
+        return

tests/wrong_type/return_value_method.jou

@@ -0,0 +1,3 @@
+class Foo:
+    def bar(self) -> byte:
+        return 1  # Error: attempting to return a value of type int from method 'bar' defined with '-> byte'