spec-fn 2.0.0

A proof-of-concept crate of adding 'function specialization' to rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33

use proc_macro2::Span;
use syn::{
    parse::{Parse, ParseStream},
    Attribute, Result, Signature, Token, Visibility,
};

pub struct SpecFn {
    pub attrs: Vec<Attribute>,
    pub vis: Visibility,
    pub sig: Signature,
    pub span: Span,
}

impl Parse for SpecFn {
    fn parse(input: ParseStream) -> Result<Self> {
        let start = input.span();

        // Parse attributes first.
        let attrs: Vec<Attribute> = input.call(Attribute::parse_outer)?;

        // Parse the rest of the function signature
        let vis: Visibility = input.parse()?;
        let sig: Signature = input.parse()?;
        let _: Token![;] = input.parse()?;

        Ok(SpecFn {
            attrs,
            vis,
            sig,
            span: start.join(input.span()).unwrap_or(start),
        })
    }
}