diff options
Diffstat (limited to 'compiler/rustc_span/src/source_map.rs')
| -rw-r--r-- | compiler/rustc_span/src/source_map.rs | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/compiler/rustc_span/src/source_map.rs b/compiler/rustc_span/src/source_map.rs index 1824510a974..c53fe084c4d 100644 --- a/compiler/rustc_span/src/source_map.rs +++ b/compiler/rustc_span/src/source_map.rs @@ -744,6 +744,21 @@ impl SourceMap { }) } + /// Extends the given `Span` to previous character while the previous character matches the predicate + pub fn span_extend_prev_while( + &self, + span: Span, + f: impl Fn(char) -> bool, + ) -> Result<Span, SpanSnippetError> { + self.span_to_source(span, |s, start, _end| { + let n = s[..start] + .char_indices() + .rfind(|&(_, c)| !f(c)) + .map_or(start, |(i, _)| start - i - 1); + Ok(span.with_lo(span.lo() - BytePos(n as u32))) + }) + } + /// Extends the given `Span` to just before the next occurrence of `c`. pub fn span_extend_to_next_char(&self, sp: Span, c: char, accept_newlines: bool) -> Span { if let Ok(next_source) = self.span_to_next_source(sp) { |