1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 2
3 use proc_macro::{token_stream, Group, TokenStr !! 3 use proc_macro::{token_stream, Group, Punct, Spacing, TokenStream, TokenTree};
4 4
5 pub(crate) fn try_ident(it: &mut token_stream: 5 pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> {
6 if let Some(TokenTree::Ident(ident)) = it. 6 if let Some(TokenTree::Ident(ident)) = it.next() {
7 Some(ident.to_string()) 7 Some(ident.to_string())
8 } else { 8 } else {
9 None 9 None
10 } 10 }
11 } 11 }
12 12
13 pub(crate) fn try_literal(it: &mut token_strea 13 pub(crate) fn try_literal(it: &mut token_stream::IntoIter) -> Option<String> {
14 if let Some(TokenTree::Literal(literal)) = 14 if let Some(TokenTree::Literal(literal)) = it.next() {
15 Some(literal.to_string()) 15 Some(literal.to_string())
16 } else { 16 } else {
17 None 17 None
18 } 18 }
19 } 19 }
20 20
21 pub(crate) fn try_string(it: &mut token_stream 21 pub(crate) fn try_string(it: &mut token_stream::IntoIter) -> Option<String> {
22 try_literal(it).and_then(|string| { 22 try_literal(it).and_then(|string| {
23 if string.starts_with('\"') && string. 23 if string.starts_with('\"') && string.ends_with('\"') {
24 let content = &string[1..string.le 24 let content = &string[1..string.len() - 1];
25 if content.contains('\\') { 25 if content.contains('\\') {
26 panic!("Escape sequences in st 26 panic!("Escape sequences in string literals not yet handled");
27 } 27 }
28 Some(content.to_string()) 28 Some(content.to_string())
29 } else if string.starts_with("r\"") { 29 } else if string.starts_with("r\"") {
30 panic!("Raw string literals are no 30 panic!("Raw string literals are not yet handled");
31 } else { 31 } else {
32 None 32 None
33 } 33 }
34 }) 34 })
35 } 35 }
36 36
37 pub(crate) fn expect_ident(it: &mut token_stre 37 pub(crate) fn expect_ident(it: &mut token_stream::IntoIter) -> String {
38 try_ident(it).expect("Expected Ident") 38 try_ident(it).expect("Expected Ident")
39 } 39 }
40 40
41 pub(crate) fn expect_punct(it: &mut token_stre 41 pub(crate) fn expect_punct(it: &mut token_stream::IntoIter) -> char {
42 if let TokenTree::Punct(punct) = it.next() 42 if let TokenTree::Punct(punct) = it.next().expect("Reached end of token stream for Punct") {
43 punct.as_char() 43 punct.as_char()
44 } else { 44 } else {
45 panic!("Expected Punct"); 45 panic!("Expected Punct");
46 } 46 }
47 } 47 }
48 48
49 pub(crate) fn expect_string(it: &mut token_str 49 pub(crate) fn expect_string(it: &mut token_stream::IntoIter) -> String {
50 try_string(it).expect("Expected string") 50 try_string(it).expect("Expected string")
51 } 51 }
52 52
53 pub(crate) fn expect_string_ascii(it: &mut tok 53 pub(crate) fn expect_string_ascii(it: &mut token_stream::IntoIter) -> String {
54 let string = try_string(it).expect("Expect 54 let string = try_string(it).expect("Expected string");
55 assert!(string.is_ascii(), "Expected ASCII 55 assert!(string.is_ascii(), "Expected ASCII string");
56 string 56 string
57 } 57 }
58 58
59 pub(crate) fn expect_group(it: &mut token_stre 59 pub(crate) fn expect_group(it: &mut token_stream::IntoIter) -> Group {
60 if let TokenTree::Group(group) = it.next() 60 if let TokenTree::Group(group) = it.next().expect("Reached end of token stream for Group") {
61 group 61 group
62 } else { 62 } else {
63 panic!("Expected Group"); 63 panic!("Expected Group");
64 } 64 }
65 } 65 }
66 66
67 pub(crate) fn expect_end(it: &mut token_stream 67 pub(crate) fn expect_end(it: &mut token_stream::IntoIter) {
68 if it.next().is_some() { 68 if it.next().is_some() {
69 panic!("Expected end"); 69 panic!("Expected end");
70 } 70 }
71 } 71 }
72 72
73 /// Parsed generics. <<
74 /// <<
75 /// See the field documentation for an explana <<
76 /// <<
77 /// # Examples <<
78 /// <<
79 /// ```rust,ignore <<
80 /// # let input = todo!(); <<
81 /// let (Generics { decl_generics, impl_generi <<
82 /// quote! { <<
83 /// struct Foo<$($decl_generics)*> { <<
84 /// // ... <<
85 /// } <<
86 /// <<
87 /// impl<$impl_generics> Foo<$ty_generics> <<
88 /// fn foo() { <<
89 /// // ... <<
90 /// } <<
91 /// } <<
92 /// } <<
93 /// ``` <<
94 pub(crate) struct Generics { 73 pub(crate) struct Generics {
95 /// The generics with bounds and default v <<
96 /// <<
97 /// Use this on type definitions e.g. `str <<
98 pub(crate) decl_generics: Vec<TokenTree>, <<
99 /// The generics with bounds (e.g. `T: Clo <<
100 /// <<
101 /// Use this on `impl` blocks e.g. `impl<$ <<
102 pub(crate) impl_generics: Vec<TokenTree>, 74 pub(crate) impl_generics: Vec<TokenTree>,
103 /// The generics without bounds and withou <<
104 /// <<
105 /// Use this when you use the type that is <<
106 /// `Foo<$ty_generics>`. <<
107 pub(crate) ty_generics: Vec<TokenTree>, 75 pub(crate) ty_generics: Vec<TokenTree>,
108 } 76 }
109 77
110 /// Parses the given `TokenStream` into `Gener 78 /// Parses the given `TokenStream` into `Generics` and the rest.
111 /// 79 ///
112 /// The generics are not present in the rest, 80 /// The generics are not present in the rest, but a where clause might remain.
113 pub(crate) fn parse_generics(input: TokenStrea 81 pub(crate) fn parse_generics(input: TokenStream) -> (Generics, Vec<TokenTree>) {
114 // The generics with bounds and default va <<
115 let mut decl_generics = vec![]; <<
116 // `impl_generics`, the declared generics 82 // `impl_generics`, the declared generics with their bounds.
117 let mut impl_generics = vec![]; 83 let mut impl_generics = vec![];
118 // Only the names of the generics, without 84 // Only the names of the generics, without any bounds.
119 let mut ty_generics = vec![]; 85 let mut ty_generics = vec![];
120 // Tokens not related to the generics e.g. 86 // Tokens not related to the generics e.g. the `where` token and definition.
121 let mut rest = vec![]; 87 let mut rest = vec![];
122 // The current level of `<`. 88 // The current level of `<`.
123 let mut nesting = 0; 89 let mut nesting = 0;
124 let mut toks = input.into_iter(); 90 let mut toks = input.into_iter();
125 // If we are at the beginning of a generic 91 // If we are at the beginning of a generic parameter.
126 let mut at_start = true; 92 let mut at_start = true;
127 let mut skip_until_comma = false; !! 93 for tt in &mut toks {
128 while let Some(tt) = toks.next() { <<
129 if nesting == 1 && matches!(&tt, Token <<
130 // Found the end of the generics. <<
131 break; <<
132 } else if nesting >= 1 { <<
133 decl_generics.push(tt.clone()); <<
134 } <<
135 match tt.clone() { 94 match tt.clone() {
136 TokenTree::Punct(p) if p.as_char() 95 TokenTree::Punct(p) if p.as_char() == '<' => {
137 if nesting >= 1 && !skip_until !! 96 if nesting >= 1 {
138 // This is inside of the g 97 // This is inside of the generics and part of some bound.
139 impl_generics.push(tt); 98 impl_generics.push(tt);
140 } 99 }
141 nesting += 1; 100 nesting += 1;
142 } 101 }
143 TokenTree::Punct(p) if p.as_char() 102 TokenTree::Punct(p) if p.as_char() == '>' => {
144 // This is a parsing error, so 103 // This is a parsing error, so we just end it here.
145 if nesting == 0 { 104 if nesting == 0 {
146 break; 105 break;
147 } else { 106 } else {
148 nesting -= 1; 107 nesting -= 1;
149 if nesting >= 1 && !skip_u !! 108 if nesting >= 1 {
150 // We are still inside 109 // We are still inside of the generics and part of some bound.
151 impl_generics.push(tt) 110 impl_generics.push(tt);
152 } 111 }
>> 112 if nesting == 0 {
>> 113 break;
>> 114 }
153 } 115 }
154 } 116 }
155 TokenTree::Punct(p) if skip_until_ !! 117 tt => {
156 if nesting == 1 { 118 if nesting == 1 {
157 impl_generics.push(tt.clon !! 119 // Here depending on the token, it might be a generic variable name.
158 impl_generics.push(tt); !! 120 match &tt {
159 skip_until_comma = false; !! 121 // Ignore const.
160 } !! 122 TokenTree::Ident(i) if i.to_string() == "const" => {}
161 } !! 123 TokenTree::Ident(_) if at_start => {
162 _ if !skip_until_comma => { !! 124 ty_generics.push(tt.clone());
163 match nesting { !! 125 // We also already push the `,` token, this makes it easier to append
164 // If we haven't entered t !! 126 // generics.
165 0 => rest.push(tt), !! 127 ty_generics.push(TokenTree::Punct(Punct::new(',', Spacing::Alone)));
166 1 => { !! 128 at_start = false;
167 // Here depending on t !! 129 }
168 match tt.clone() { !! 130 TokenTree::Punct(p) if p.as_char() == ',' => at_start = true,
169 TokenTree::Ident(i !! 131 // Lifetimes begin with `'`.
170 let Some(name) !! 132 TokenTree::Punct(p) if p.as_char() == '\'' && at_start => {
171 // Parsing !! 133 ty_generics.push(tt.clone());
172 break; <<
173 }; <<
174 impl_generics. <<
175 impl_generics. <<
176 ty_generics.pu <<
177 decl_generics. <<
178 at_start = fal <<
179 } <<
180 TokenTree::Ident(_ <<
181 impl_generics. <<
182 ty_generics.pu <<
183 at_start = fal <<
184 } <<
185 TokenTree::Punct(p <<
186 impl_generics. <<
187 ty_generics.pu <<
188 at_start = tru <<
189 } <<
190 // Lifetimes begin <<
191 TokenTree::Punct(p <<
192 impl_generics. <<
193 ty_generics.pu <<
194 } <<
195 // Generics can ha <<
196 TokenTree::Punct(p <<
197 skip_until_com <<
198 } <<
199 _ => impl_generics <<
200 } 134 }
>> 135 _ => {}
201 } 136 }
202 _ => impl_generics.push(tt !! 137 }
>> 138 if nesting >= 1 {
>> 139 impl_generics.push(tt);
>> 140 } else if nesting == 0 {
>> 141 // If we haven't entered the generics yet, we still want to keep these tokens.
>> 142 rest.push(tt);
203 } 143 }
204 } 144 }
205 _ => {} <<
206 } 145 }
207 } 146 }
208 rest.extend(toks); 147 rest.extend(toks);
209 ( 148 (
210 Generics { 149 Generics {
211 impl_generics, 150 impl_generics,
212 decl_generics, <<
213 ty_generics, 151 ty_generics,
214 }, 152 },
215 rest, 153 rest,
216 ) 154 )
217 } 155 }
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