From 129d962041ef76b71e98cbfd187b2f5f37a57dc7 Mon Sep 17 00:00:00 2001
From: Rob Rix <rob.rix@me.com>
Date: Wed, 26 Apr 2017 12:31:00 -0400
Subject: [PATCH] Add a leaf combinator.

---
 src/Language/Ruby/Syntax.hs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/Language/Ruby/Syntax.hs b/src/Language/Ruby/Syntax.hs
index 443eb4585..05bf3be4b 100644
--- a/src/Language/Ruby/Syntax.hs
+++ b/src/Language/Ruby/Syntax.hs
@@ -105,6 +105,9 @@ literal  =  term <*> (Literal.true <$ symbol Language.Ruby.Syntax.True <* source
 term :: InUnion Syntax' f => Assignment (Node grammar) (f (Term Syntax Location) -> Term Syntax Location)
 term =  (\ a f -> cofree $ a :< inj f) <$> location
 
+leaf :: (Enum symbol, Eq symbol, InUnion Syntax' f) => (ByteString -> f (Term Syntax Location)) -> symbol -> Assignment (Node symbol) (Term Syntax Location)
+leaf f s = symbol s *> pure (\ a -> cofree . (a :<) . inj . f) <*> location <*> source
+
 optional :: Assignment (Node Grammar) (Term Syntax Location) -> Assignment (Node Grammar) (Term Syntax Location)
 optional a = a <|> term <*> pure Syntax.Empty