Providing a more accurate message when trying to use a reserved word as a function name

[andoni-hazaiah]

Hi 👋!

When the code is compiled, the compiler says Error: A function name must start with lower case, as names starting with upper case are reserved for types., pointing to double function name. But it's not accurate for our situation where we're trying to use a reserved type keyword.

Sample code:

module arrays;

import std::io;

fn void double() {}

fn void main() {}

saying something like "Cannot use the reserved type 'double' as a function name" instead of the current misleading message about case sensitivity would be more helpful.

In parse_func_macro_header, when it sees this token type and a left parenthesis, it assumes it's trying to define a function with an uppercase name (which is reserved for types).

The error message could be improved by:

• a. Adding a specific check for built-in type tokens in parse_func_macro_header
• b. Providing a more accurate error message when trying to use a reserved keyword as a function name as above.

[lerno]

This should now be fixed.

[andoni-hazaiah]

Here's a suggested improvement to the code in parse_global.c, I couldn’t test it though:

if (method_type->kind == TYPE_INFO_IDENTIFIER) {
    if (tok_is(c, TOKEN_LPAREN)) {
        // Check if it's a built-in type token
        if (method_type->type >= TOKEN_VOID && method_type->type <= TOKEN_TYPEID) {
            RETURN_PRINT_ERROR_AT(false, method_type, "Cannot use the reserved type '%s' as a function name.", token_type_to_string(method_type->type));
        }
        RETURN_PRINT_ERROR_AT(false, method_type, "A function name must start with lower case, as names starting with upper case are reserved for types.");
    }
    RETURN_PRINT_ERROR_AT(false, method_type, "There is unexpectedly a type after the return type, did you forget a '.'?");
}

This change would:

1. First check if we're trying to use a built-in type token as a function name
2. If so, provide a more specific error message mentioning the reserved type name
3. Otherwise, fall back to the existing error messages

[lerno]

Was there a problem with the solution I wrote?

[andoni-hazaiah]

Was there a problem with the solution I wrote?

Hey there!

I apologize for the delay.

I was able to see it only after posting my response.

Thank you!