syn_pub_items/
tt.rs

1use std::hash::{Hash, Hasher};
2
3use proc_macro2::{Delimiter, TokenStream, TokenTree};
4
5pub struct TokenTreeHelper<'a>(pub &'a TokenTree);
6
7impl<'a> PartialEq for TokenTreeHelper<'a> {
8    fn eq(&self, other: &Self) -> bool {
9        use proc_macro2::Spacing;
10
11        match (self.0, other.0) {
12            (&TokenTree::Group(ref g1), &TokenTree::Group(ref g2)) => {
13                match (g1.delimiter(), g2.delimiter()) {
14                    (Delimiter::Parenthesis, Delimiter::Parenthesis)
15                    | (Delimiter::Brace, Delimiter::Brace)
16                    | (Delimiter::Bracket, Delimiter::Bracket)
17                    | (Delimiter::None, Delimiter::None) => {}
18                    _ => return false,
19                }
20
21                let s1 = g1.stream().clone().into_iter();
22                let mut s2 = g2.stream().clone().into_iter();
23
24                for item1 in s1 {
25                    let item2 = match s2.next() {
26                        Some(item) => item,
27                        None => return false,
28                    };
29                    if TokenTreeHelper(&item1) != TokenTreeHelper(&item2) {
30                        return false;
31                    }
32                }
33                s2.next().is_none()
34            }
35            (&TokenTree::Punct(ref o1), &TokenTree::Punct(ref o2)) => {
36                o1.as_char() == o2.as_char()
37                    && match (o1.spacing(), o2.spacing()) {
38                        (Spacing::Alone, Spacing::Alone) | (Spacing::Joint, Spacing::Joint) => true,
39                        _ => false,
40                    }
41            }
42            (&TokenTree::Literal(ref l1), &TokenTree::Literal(ref l2)) => {
43                l1.to_string() == l2.to_string()
44            }
45            (&TokenTree::Ident(ref s1), &TokenTree::Ident(ref s2)) => s1 == s2,
46            _ => false,
47        }
48    }
49}
50
51impl<'a> Hash for TokenTreeHelper<'a> {
52    fn hash<H: Hasher>(&self, h: &mut H) {
53        use proc_macro2::Spacing;
54
55        match *self.0 {
56            TokenTree::Group(ref g) => {
57                0u8.hash(h);
58                match g.delimiter() {
59                    Delimiter::Parenthesis => 0u8.hash(h),
60                    Delimiter::Brace => 1u8.hash(h),
61                    Delimiter::Bracket => 2u8.hash(h),
62                    Delimiter::None => 3u8.hash(h),
63                }
64
65                for item in g.stream().clone() {
66                    TokenTreeHelper(&item).hash(h);
67                }
68                0xffu8.hash(h); // terminator w/ a variant we don't normally hash
69            }
70            TokenTree::Punct(ref op) => {
71                1u8.hash(h);
72                op.as_char().hash(h);
73                match op.spacing() {
74                    Spacing::Alone => 0u8.hash(h),
75                    Spacing::Joint => 1u8.hash(h),
76                }
77            }
78            TokenTree::Literal(ref lit) => (2u8, lit.to_string()).hash(h),
79            TokenTree::Ident(ref word) => (3u8, word).hash(h),
80        }
81    }
82}
83
84pub struct TokenStreamHelper<'a>(pub &'a TokenStream);
85
86impl<'a> PartialEq for TokenStreamHelper<'a> {
87    fn eq(&self, other: &Self) -> bool {
88        let left = self.0.clone().into_iter().collect::<Vec<_>>();
89        let right = other.0.clone().into_iter().collect::<Vec<_>>();
90        if left.len() != right.len() {
91            return false;
92        }
93        for (a, b) in left.into_iter().zip(right) {
94            if TokenTreeHelper(&a) != TokenTreeHelper(&b) {
95                return false;
96            }
97        }
98        true
99    }
100}
101
102impl<'a> Hash for TokenStreamHelper<'a> {
103    fn hash<H: Hasher>(&self, state: &mut H) {
104        let tts = self.0.clone().into_iter().collect::<Vec<_>>();
105        tts.len().hash(state);
106        for tt in tts {
107            TokenTreeHelper(&tt).hash(state);
108        }
109    }
110}
syn_pub_items/tt.rs

syn_pub_items/
tt.rs
