| 1 | |
| 2 |
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| 3 | use proc_macro2::{Delimiter, TokenStream, TokenTree};
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| 4 | use std::hash::{Hash, Hasher};
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| 5 |
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| 6 | pub(crate) struct TokenTreeHelper<'a>(pub &'a TokenTree);
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| 7 |
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| 8 | impl<'a> PartialEq for TokenTreeHelper<'a> {
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| 9 | fn eq(&self, other: &Self) -> bool {
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| 10 | use proc_macro2::Spacing;
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| 11 |
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| 12 | match (self.0, other.0) {
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| 13 | (TokenTree::Group(g1), TokenTree::Group(g2)) => {
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| 14 | match (g1.delimiter(), g2.delimiter()) {
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| 15 | (Delimiter::Parenthesis, Delimiter::Parenthesis)
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| 16 | | (Delimiter::Brace, Delimiter::Brace)
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| 17 | | (Delimiter::Bracket, Delimiter::Bracket)
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| 18 | | (Delimiter::None, Delimiter::None) => {}
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| 19 | _ => return false,
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| 20 | }
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| 21 |
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| 22 | let s1 = g1.stream().into_iter();
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| 23 | let mut s2 = g2.stream().into_iter();
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| 24 |
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| 25 | for item1 in s1 {
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| 26 | let item2 = match s2.next() {
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| 27 | Some(item) => item,
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| 28 | None => return false,
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| 29 | };
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| 30 | if TokenTreeHelper(&item1) != TokenTreeHelper(&item2) {
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| 31 | return false;
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| 32 | }
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| 33 | }
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| 34 | s2.next().is_none()
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| 35 | }
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| 36 | (TokenTree::Punct(o1), TokenTree::Punct(o2)) => {
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| 37 | o1.as_char() == o2.as_char()
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| 38 | && match (o1.spacing(), o2.spacing()) {
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| 39 | (Spacing::Alone, Spacing::Alone) | (Spacing::Joint, Spacing::Joint) => true,
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| 40 | _ => false,
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| 41 | }
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| 42 | }
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| 43 | (TokenTree::Literal(l1), TokenTree::Literal(l2)) => l1.to_string() == l2.to_string(),
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| 44 | (TokenTree::Ident(s1), TokenTree::Ident(s2)) => s1 == s2,
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| 45 | _ => false,
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| 46 | }
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| 47 | }
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| 48 | }
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| 49 |
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| 50 | impl<'a> Hash for TokenTreeHelper<'a> {
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| 51 | fn hash<H: Hasher>(&self, h: &mut H) {
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| 52 | use proc_macro2::Spacing;
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| 53 |
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| 54 | match self.0 {
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| 55 | TokenTree::Group(g) => {
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| 56 | 0u8.hash(h);
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| 57 | match g.delimiter() {
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| 58 | Delimiter::Parenthesis => 0u8.hash(h),
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| 59 | Delimiter::Brace => 1u8.hash(h),
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| 60 | Delimiter::Bracket => 2u8.hash(h),
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| 61 | Delimiter::None => 3u8.hash(h),
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| 62 | }
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| 63 |
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| 64 | for item in g.stream() {
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| 65 | TokenTreeHelper(&item).hash(h);
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| 66 | }
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| 67 | 0xFFu8.hash(h); |
| 68 | }
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| 69 | TokenTree::Punct(op) => {
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| 70 | 1u8.hash(h);
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| 71 | op.as_char().hash(h);
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| 72 | match op.spacing() {
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| 73 | Spacing::Alone => 0u8.hash(h),
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| 74 | Spacing::Joint => 1u8.hash(h),
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| 75 | }
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| 76 | }
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| 77 | TokenTree::Literal(lit) => (2u8, lit.to_string()).hash(h),
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| 78 | TokenTree::Ident(word) => (3u8, word).hash(h),
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| 79 | }
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| 80 | }
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| 81 | }
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| 82 |
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| 83 | pub(crate) struct TokenStreamHelper<'a>(pub &'a TokenStream);
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| 84 |
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| 85 | impl<'a> PartialEq for TokenStreamHelper<'a> {
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| 86 | fn eq(&self, other: &Self) -> bool {
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| 87 | let left = self.0.clone().into_iter().collect::<Vec<_>>();
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| 88 | let right = other.0.clone().into_iter().collect::<Vec<_>>();
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| 89 | if left.len() != right.len() {
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| 90 | return false;
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| 91 | }
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| 92 | for (a, b) in left.into_iter().zip(right) {
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| 93 | if TokenTreeHelper(&a) != TokenTreeHelper(&b) {
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| 94 | return false;
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| 95 | }
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| 96 | }
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| 97 | true
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| 98 | }
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| 99 | }
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| 100 |
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| 101 | impl<'a> Hash for TokenStreamHelper<'a> {
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| 102 | fn hash<H: Hasher>(&self, state: &mut H) {
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| 103 | let tts = self.0.clone().into_iter().collect::<Vec<_>>();
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| 104 | tts.len().hash(state);
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| 105 | for tt in tts {
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| 106 | TokenTreeHelper(&tt).hash(state);
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| 107 | }
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| 108 | }
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| 109 | }
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