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change macro ambiguity example from ty to ident #30406

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Dec 18, 2015
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change macro ambiguity example from ty to ident #30406

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6 changes: 3 additions & 3 deletions src/doc/book/macros.md
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Expand Up @@ -485,10 +485,10 @@ These rules provide some flexibility for Rust’s syntax to evolve without
breaking existing macros.

The macro system does not deal with parse ambiguity at all. For example, the
grammar `$($t:ty)* $e:expr` will always fail to parse, because the parser would
be forced to choose between parsing `$t` and parsing `$e`. Changing the
grammar `$($i:ident)* $e:expr` will always fail to parse, because the parser would
be forced to choose between parsing `$i` and parsing `$e`. Changing the
invocation syntax to put a distinctive token in front can solve the problem. In
this case, you can write `$(T $t:ty)* E $e:exp`.
this case, you can write `$(I $i:ident)* E $e:expr`.

[item]: ../reference.html#items

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