Merge #2273

2273: goto in macro calls r=matklad a=matklad

![goto](https://user-images.githubusercontent.com/1711539/68984944-2a50ba80-0824-11ea-896c-c0ea8edcd0d6.gif)

This builds on the awesome infrastructure created by @edwin0cheng 

Co-authored-by: Aleksey Kladov <[email protected]>

1 files changed, 6 insertions, 0 deletions

diff --git a/crates/ra_mbe/src/syntax_bridge.rs b/crates/ra_mbe/src/syntax_bridge.rs
index 3f57ce3b5..37382d2df 100644
--- a/crates/ra_mbe/src/syntax_bridge.rs
+++ b/crates/ra_mbe/src/syntax_bridge.rs
@@ -77,6 +77,12 @@ pub fn token_tree_to_syntax_node(
 }
 
 impl TokenMap {
+    pub fn token_by_offset(&self, relative_offset: TextUnit) -> Option<tt::TokenId> {
+        let (idx, _) =
+            self.tokens.iter().enumerate().find(|(_, range)| range.contains(relative_offset))?;
+        Some(tt::TokenId(idx as u32))
+    }
+
     pub fn relative_range_of(&self, tt: tt::TokenId) -> Option<TextRange> {
         let idx = tt.0 as usize;
         self.tokens.get(idx).copied()