Syntax extensions (and macros) that start a line want to be a whole statement

[rust-highfive]

Issue by paulstansifer
Thursday Apr 18, 2013 at 19:37 GMT

For earlier discussion, see rust-lang/rust#5941

This issue was labelled with: A-parser, A-syntaxext, P-high in the Rust repository

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{ stringify!(bees).to_owned() }

 foo.rs:5:27: 5:28 error: unexpected token: `.`
 foo.rs:5          { stringify!(bees).to_owned() }
                                     ^

However, if you wrap the macro invocation in parens...

 { (stringify!(bees)).to_owned() }

...it works.

The tricky thing about this problem is that, when the parser sees stringify!, it doesn't know whether it'll be a statement macro or an expression macro; currently, it commits to the former, which breaks if the invocation has to be an expression.

[Stebalien]

Triage: fixed (also, probably in the wrong repo...).

[Stebalien]

@alexcrichton (at random, sorry)