haskell: Properly highlight promoted data constructors (#21)

Unfortunately there is a bit of ambiguity with char literals. For instance, the data constructor `A'` would be `'A'` in promoted form. This will still be highlighted as as char literal but this is the best we can do without more context.
pyrmont · May 11, 2019 · c43527a · c43527a
1 parent ef830b1
commit c43527a
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/lib/rouge/lexers/haskell.rb b/lib/rouge/lexers/haskell.rb
@@ -61,6 +61,7 @@ def self.detect?(text)
         # rule /^[_a-z][\w']*/, Name::Function
         rule /[_a-z][\w']*/, Name
         rule /[A-Z][\w']*/, Keyword::Type
+        rule /'[A-Z]\w[\w']*/, Keyword::Type  # promoted data constructor
 
         # lambda operator
         rule %r(\\(?![:!#\$\%&*+.\\/<=>?@^\|~-]+)), Name::Function