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
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
|
use std::fmt::Display;
use proc_macro2::{TokenStream, TokenTree};
use quote::{ToTokens, TokenStreamExt};
use syn::parse::{Parse, ParseStream};
use syn::{braced, bracketed, token, AttrStyle, Attribute, Signature, Token, Visibility};
pub fn token_stream_with_error(mut tokens: TokenStream, error: syn::Error) -> TokenStream {
tokens.extend(error.into_compile_error());
tokens
}
pub fn error<A: ToTokens, T: Display>(s: &mut TokenStream, obj: A, msg: T) {
s.extend(syn::Error::new_spanned(obj.into_token_stream(), msg).into_compile_error())
}
/// Function signature and body.
///
/// Same as `syn`'s `ItemFn` except we keep the body as a TokenStream instead of
/// parsing it. This makes the macro not error if there's a syntax error in the body,
/// which helps IDE autocomplete work better.
#[derive(Debug, Clone)]
pub struct ItemFn {
pub attrs: Vec<Attribute>,
pub vis: Visibility,
pub sig: Signature,
pub brace_token: token::Brace,
pub body: TokenStream,
}
impl Parse for ItemFn {
fn parse(input: ParseStream) -> syn::Result<Self> {
let mut attrs = input.call(Attribute::parse_outer)?;
let vis: Visibility = input.parse()?;
let sig: Signature = input.parse()?;
let content;
let brace_token = braced!(content in input);
while content.peek(Token![#]) && content.peek2(Token![!]) {
let content2;
attrs.push(Attribute {
pound_token: content.parse()?,
style: AttrStyle::Inner(content.parse()?),
bracket_token: bracketed!(content2 in content),
meta: content2.parse()?,
});
}
let mut body = Vec::new();
while !content.is_empty() {
body.push(content.parse::<TokenTree>()?);
}
let body = body.into_iter().collect();
Ok(ItemFn {
attrs,
vis,
sig,
brace_token,
body,
})
}
}
impl ToTokens for ItemFn {
fn to_tokens(&self, tokens: &mut TokenStream) {
tokens.append_all(self.attrs.iter().filter(|a| matches!(a.style, AttrStyle::Outer)));
self.vis.to_tokens(tokens);
self.sig.to_tokens(tokens);
self.brace_token.surround(tokens, |tokens| {
tokens.append_all(self.body.clone());
});
}
}
|
