diff options
Diffstat (limited to 'src/libsyntax_ext')
| -rw-r--r-- | src/libsyntax_ext/format.rs | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/src/libsyntax_ext/format.rs b/src/libsyntax_ext/format.rs index 47394c02b41..d9ca693aca5 100644 --- a/src/libsyntax_ext/format.rs +++ b/src/libsyntax_ext/format.rs @@ -138,15 +138,23 @@ fn parse_args<'a>( } let fmtstr = p.parse_expr()?; + let mut first = true; let mut named = false; while p.token != token::Eof { if !p.eat(&token::Comma) { - let mut err = ecx.struct_span_err(p.token.span, "expected token: `,`"); - err.span_label(p.token.span, "expected `,`"); - p.maybe_annotate_with_ascription(&mut err, false); - return Err(err); + if first { + // After `format!(""` we always expect *only* a comma... + let mut err = ecx.struct_span_err(p.token.span, "expected token: `,`"); + err.span_label(p.token.span, "expected `,`"); + p.maybe_annotate_with_ascription(&mut err, false); + return Err(err); + } else { + // ...after that delegate to `expect` to also include the other expected tokens. + return Err(p.expect(&token::Comma).err().unwrap()); + } } + first = false; if p.token == token::Eof { break; } // accept trailing commas |