diff options
Diffstat (limited to 'src/doc/rustc-dev-guide/src/macro-expansion.md')
| -rw-r--r-- | src/doc/rustc-dev-guide/src/macro-expansion.md | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/src/doc/rustc-dev-guide/src/macro-expansion.md b/src/doc/rustc-dev-guide/src/macro-expansion.md index 55a550b56e8..a43c0939452 100644 --- a/src/doc/rustc-dev-guide/src/macro-expansion.md +++ b/src/doc/rustc-dev-guide/src/macro-expansion.md @@ -134,8 +134,9 @@ it calls back to the normal Rust parser to get the contents of that non-terminal. In this case, the Rust parser would look for an `ident` token, which it finds (`foo`) and returns to the macro parser. Then, the macro parser proceeds in parsing as normal. Also, note that exactly one of the matchers from -the various arms should match the invocation (otherwise, the macro is -ambiguous). +the various arms should match the invocation; if there is more than one match, +the parse is ambiguous, while if there are no matches at all, there is a syntax +error. For more information about the macro parser's implementation, see the comments in [`src/libsyntax/ext/tt/macro_parser.rs`][code_mp]. |