1  // SPDX-License-Identifier: GPL-2.0
2  
3  use proc_macro::{token_stream, TokenTree};
4  
try_ident(it: &mut token_stream::IntoIter) -> Option<String>5  pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> {
6      if let Some(TokenTree::Ident(ident)) = it.next() {
7          Some(ident.to_string())
8      } else {
9          None
10      }
11  }
12  
try_literal(it: &mut token_stream::IntoIter) -> Option<String>13  pub(crate) fn try_literal(it: &mut token_stream::IntoIter) -> Option<String> {
14      if let Some(TokenTree::Literal(literal)) = it.next() {
15          Some(literal.to_string())
16      } else {
17          None
18      }
19  }
20  
try_string(it: &mut token_stream::IntoIter) -> Option<String>21  pub(crate) fn try_string(it: &mut token_stream::IntoIter) -> Option<String> {
22      try_literal(it).and_then(|string| {
23          if string.starts_with('\"') && string.ends_with('\"') {
24              let content = &string[1..string.len() - 1];
25              if content.contains('\\') {
26                  panic!("Escape sequences in string literals not yet handled");
27              }
28              Some(content.to_string())
29          } else if string.starts_with("r\"") {
30              panic!("Raw string literals are not yet handled");
31          } else {
32              None
33          }
34      })
35  }
36  
expect_ident(it: &mut token_stream::IntoIter) -> String37  pub(crate) fn expect_ident(it: &mut token_stream::IntoIter) -> String {
38      try_ident(it).expect("Expected Ident")
39  }
40  
expect_punct(it: &mut token_stream::IntoIter) -> char41  pub(crate) fn expect_punct(it: &mut token_stream::IntoIter) -> char {
42      if let TokenTree::Punct(punct) = it.next().expect("Reached end of token stream for Punct") {
43          punct.as_char()
44      } else {
45          panic!("Expected Punct");
46      }
47  }
48  
expect_string(it: &mut token_stream::IntoIter) -> String49  pub(crate) fn expect_string(it: &mut token_stream::IntoIter) -> String {
50      try_string(it).expect("Expected string")
51  }
52  
expect_string_ascii(it: &mut token_stream::IntoIter) -> String53  pub(crate) fn expect_string_ascii(it: &mut token_stream::IntoIter) -> String {
54      let string = try_string(it).expect("Expected string");
55      assert!(string.is_ascii(), "Expected ASCII string");
56      string
57  }
58  
expect_end(it: &mut token_stream::IntoIter)59  pub(crate) fn expect_end(it: &mut token_stream::IntoIter) {
60      if it.next().is_some() {
61          panic!("Expected end");
62      }
63  }
64