Avoid excessive backtracing in data declarations

JustusAdam · May 13, 2020 · 1bb6423 · 1bb6423
1 parent 79b3a38
commit 1bb6423
Show file tree

Hide file tree

Showing 2 changed files with 7 additions and 4 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## x.x.x. - Unreleased
+
+- Fix excessive backtracking in regular expression for data declarations
+  ([#161](https://github.com/JustusAdam/language-haskell/issues/161)).
+
 ## 3.2.0 - 11.05.2020
 
 - Improvements to highlighting data constructors:

diff --git a/syntaxes/haskell.YAML-tmLanguage b/syntaxes/haskell.YAML-tmLanguage
@@ -965,14 +965,12 @@ repository:
           '2': {name: keyword.operator.pipe.haskell}
         end: >-
           (?x)
-
-
+            (?:\G|^)\s* # Enforce starting condition to avoid catastrophic backtracking (https://github.com/JustusAdam/language-haskell/issues/161)
             (?: # Infix data constructor
-              \s*
               # First argument
               (?:
               # Simple type
-              |(?<!')\b((?:[\p{Ll}_\p{Lu}\p{Lt}\p{Nd}'\.])+)
+                (?<!')\b((?:[\p{Ll}_\p{Lu}\p{Lt}\p{Nd}'\.])+)
               # Type inside balanced parentheses
               | ('? # Optional promotion tick
                   (?<paren>