Better error message when struct construction field name is left "implicit"

[jdm]

(Updated with concrete example:)

struct Foo {
    A: int,
    B: int
}

fn main() {
    let B = 3i;
    let x = Foo{A:1,B};
}

yields (live playpen: http://is.gd/GDjwLK)

<anon>:8:22: 8:23 error: expected `:` but found `}`
<anon>:8     let x = Foo{A:1,B};
                              ^

This feels like something we should be able to better report (possibly as a note suggestion).

Original bug report follows:

/run/media/jdm/ssd/servo/src/servo/dom/bindings/ClientRectBinding.rs:254:61: 254:62 error: expected `;` but found `{`
/run/media/jdm/ssd/servo/src/servo/dom/bindings/ClientRectBinding.rs:254 const NativeHooks: NativePropertyHooks = 
                 NativePropertyHooks { 0 as *u8, ResolveProperty, 0 as *u8, EnumerateProperties, 0 as *NativePropertyHooks };

This feels like something we should be able to better report (possibly as a note suggestion).

[catamorphism]

Not critical for 0.7. Nominating for milestone 5, production-ready

[graydon]

accepted for production ready

[graydon]

Still present, still just about as unpleasant an error message.

[pnkfelix]

assigning P-low.

[eminence]

In the latest master (e2273d9), this looks to be fixed:

struct Foo {
    A: int,
    B: int
}

fn main() {
    let x = Foo{A:1};
}

test.rs:7:13: 7:21 error: missing field: `B` [E0063]
test.rs:7     let x = Foo{A:1};
                      ^~~~~~~~

[pnkfelix]

@eminence your example does not reflect what the bug report is asking about.

Here is variant of your example that illustrates the problem in the description (which I will also add to the bug description after I finish typing this comment): http://is.gd/GDjwLK

(also updated title to better reflect the description)

[eminence]

ah, my apologies -- I did not properly understand the reported issue. thanks for the clarification.

[frewsxcv]

visiting for triage

The error message has not changed for the original code example, so this issue is still valid

[birkenfeld]

Current message:

<anon>:8:22: 8:23 error: expected `:`, found `}`
<anon>:8     let x = Foo{A:1,B};
                              ^
<anon>:8:13: 8:23 error: missing field `B` in initializer of `Foo` [E0063]
<anon>:8     let x = Foo{A:1,B};
                     ^~~~~~~~~~
<anon>:8:13: 8:23 help: see the detailed explanation for E0063

Are these two together clear enough?

[jdm]

That seems like a good enough improvement to me.