diff options
Diffstat (limited to 'vendor/syn/src/verbatim.rs')
-rw-r--r-- | vendor/syn/src/verbatim.rs | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/vendor/syn/src/verbatim.rs b/vendor/syn/src/verbatim.rs new file mode 100644 index 0000000..54dc1cf --- /dev/null +++ b/vendor/syn/src/verbatim.rs @@ -0,0 +1,33 @@ +use crate::parse::ParseStream; +use proc_macro2::{Delimiter, TokenStream}; +use std::cmp::Ordering; +use std::iter; + +pub(crate) fn between<'a>(begin: ParseStream<'a>, end: ParseStream<'a>) -> TokenStream { + let end = end.cursor(); + let mut cursor = begin.cursor(); + assert!(crate::buffer::same_buffer(end, cursor)); + + let mut tokens = TokenStream::new(); + while cursor != end { + let (tt, next) = cursor.token_tree().unwrap(); + + if crate::buffer::cmp_assuming_same_buffer(end, next) == Ordering::Less { + // A syntax node can cross the boundary of a None-delimited group + // due to such groups being transparent to the parser in most cases. + // Any time this occurs the group is known to be semantically + // irrelevant. https://github.com/dtolnay/syn/issues/1235 + if let Some((inside, _span, after)) = cursor.group(Delimiter::None) { + assert!(next == after); + cursor = inside; + continue; + } else { + panic!("verbatim end must not be inside a delimited group"); + } + } + + tokens.extend(iter::once(tt)); + cursor = next; + } + tokens +} |