mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-29 18:23:49 +00:00
e91405b9d5
Support negative numbers in Literal::from_str proc_macro::Literal has allowed negative numbers in a single literal token ever since Rust 1.29, using https://doc.rust-lang.org/stable/proc_macro/struct.Literal.html#method.isize_unsuffixed and similar constructors. ```rust let lit = proc_macro::Literal::isize_unsuffixed(-10); ``` However, the suite of constructors on Literal is not sufficient for all use cases, for example arbitrary precision floats, or custom suffixes in FFI macros. ```rust let lit = proc_macro::Literal::f64_unsuffixed(0.101001000100001000001000000100000001); // :( let lit = proc_macro::Literal::i???_suffixed(10ulong); // :( ``` For those, macros construct the literal using from_str instead, which preserves arbitrary precision, custom suffixes, base, and digit grouping. ```rust let lit = "0.101001000100001000001000000100000001".parse::<Literal>().unwrap(); let lit = "10ulong".parse::<Literal>().unwrap(); let lit = "0b1000_0100_0010_0001".parse::<Literal>().unwrap(); ``` However, until this PR it was not possible to construct a literal token that is **both** negative **and** preserving of arbitrary precision etc. This PR fixes `Literal::from_str` to recognize negative integer and float literals. |
||
---|---|---|
.. | ||
src | ||
Cargo.toml |