diff --git a/active/0000-reserve-more-numeric-types.md b/active/0000-reserve-more-numeric-types.md new file mode 100644 index 00000000000..fc1e4b37713 --- /dev/null +++ b/active/0000-reserve-more-numeric-types.md @@ -0,0 +1,30 @@ +- Start Date: 2014-06-25 +- RFC PR #: (leave this empty) +- Rust Issue #: (leave this empty) + +# Summary + +Reserve more numeric types as keywords. + +# Motivation + +It is conceivable that Rust will gain support for types such as `f128`, `f16`, +or `u128`. In the interest of backwards compatability, extend the grammar to +reserve these. + +# Detailed design + +The `INT_SUFFIX` and `FLOAT_SUFFIX` nonterminals in [the lexical +grammar](0021-lexical-syntax-simplification.md) respectively become: + +``` +INT_SUFFIX : 'i' [0-9]+ ; +FLOAT_SUFFIX : 'f' [0-9]+ ; +``` + +Additionally, identifiers matching those patterns will be *reserved words*, +not legal for use in bindings or otherwise. + +# Drawbacks + +Makes the grammar larger for types which we may never use.