expected type expression, found ',', when trying to put a method in anonymous struct literal type

[baryluk]

Zig Version

0.12.0-dev.1829+70664547c

Steps to Reproduce and Observed Output

pub fn FunctionWithCapture() type {
    return struct {
        function: fn() i32,
        pub fn call(self: *@This()) i32 {
            return self.function();
        },
    };
}

I just started playing today (coming from D, Go, C++, Python), and it was very confusing, when I got:

c.zig:6:10: error: expected type expression, found ','
        },
         ^

zig-linux-x86_64-0.12.0-dev.1829+70664547c

Expected Output

Should fail after initial (or actually just during) pub, due to reserved keyword used, or missing comma after pub, with appropriate message.

[baryluk]

Wait...

https://ziglang.org/documentation/master/#toc-struct

shows this is a correct code.

Modulo the trailing , which should not be used.

So, maybe message should be more like:

Expected identifier, function declaration, or '}', but found ','

?

[baryluk]

Similar (but slightly unrelated):

pub fn FunctionWithCapture() type {
    return struct {
        function: fn() i32,
        pub fn call(self: *@This()) i32 {
            return self.function();
        }
    };
}

pub fn main() !void {
  const T = FunctionWithCapture();
  const t = T{
    .function = fn() i32 { return 5; },
  };
}

Got:

c.zig:13:36: error: expected ',' after initializer
    .function = fn() i32 { return 5; },
                                   ^

rather confusing.

I guess this is because of #1048 and in the docs I did not find a single occurence of = fn( , and due to #1717, so probably this is not something that is actually supported.

So error, does make some sense now, but it is not super obvious to a novice.

[xdBronch]

declarations are not followed by commas, the fix is to just remove the trailing comma after the closing curly brace.

I guess this is because of 1048 and in the docs I did not find a single occurence of = fn( , and due to 1717, so probably this is not something that is actually supported.

right, the error message certainly needs some improvement but this is not meant to work