Error if function parameter is declared without a name

[SplittyDev]

Test case:

fn foo str -> () => { }

[chronium]

Would this syntax maybe have a use with anonymous parameter names maybe?

Syntax ideas:

fn foo str -> str = _

// or

fn foo_bar (i32, i32) -> i32 = _.0 * _.1

For the second example, another thought could be something like:

fn foo_bar (i32, i32) -> i32 = .0 * .0

[SplittyDev]

Yeah, that actually sounds pretty neat.

I like the . syntax more than _. though.
Imo, _ should be used for placeholders and unused variables only.

I'm in favor of allowing arbitrary piping (see #13) using a syntax like:

b |> foo (a, _, c) 

In that case, _ is clearly a placeholder and not to be used as a variable.
That is if we even decide to push that proposal further.

Anyway, this would also become possible:

fn foo (a: i32, _: i32, c: i32) -> i32 = a + c

This use of _ could be nice if a specific function prototype is technically required but not actually used, which is likely to happen in situations using FFI, interface patterns, etc.

[chronium]

For the last example,

fn foo (a: i32, i32, c: i32) -> i32 = a + c

would be the preferred method.
That does work in this stage. At least for parsing

[SplittyDev]

That would also work of course. Not sure if it's a good idea consistency-wise though. Mixing typed parameters and just types seems like a weird thing to do. Kinda hurts readability imo.