From f17896d17ee32c4cc933965fbe6017c64918236a Mon Sep 17 00:00:00 2001
From: Phil Freeman <paf31@cantab.net>
Date: Sun, 24 Aug 2014 18:48:26 -0700
Subject: [PATCH] Fix #403

---
 examples/passing/NegativeBinder.purs           | 7 +++++++
 src/Language/PureScript/Parser/Declarations.hs | 9 ++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 examples/passing/NegativeBinder.purs

diff --git a/examples/passing/NegativeBinder.purs b/examples/passing/NegativeBinder.purs
new file mode 100644
index 0000000000..d5dfe1bad9
--- /dev/null
+++ b/examples/passing/NegativeBinder.purs
@@ -0,0 +1,7 @@
+module Main where
+
+test :: Number -> Boolean
+test -1 = false
+test _  = true
+
+main = Debug.Trace.trace "Done"
diff --git a/src/Language/PureScript/Parser/Declarations.hs b/src/Language/PureScript/Parser/Declarations.hs
index 9c79a55b09..d226961e96 100644
--- a/src/Language/PureScript/Parser/Declarations.hs
+++ b/src/Language/PureScript/Parser/Declarations.hs
@@ -24,7 +24,9 @@ module Language.PureScript.Parser.Declarations (
 ) where
 
 import Data.Maybe (isJust, fromMaybe)
+
 import Control.Applicative
+import Control.Arrow ((+++))
 
 import Language.PureScript.Parser.State
 import Language.PureScript.Parser.Common
@@ -365,7 +367,12 @@ parseBooleanBinder :: P.Parsec String ParseState Binder
 parseBooleanBinder = BooleanBinder <$> booleanLiteral
 
 parseNumberBinder :: P.Parsec String ParseState Binder
-parseNumberBinder = NumberBinder <$> C.integerOrFloat
+parseNumberBinder = NumberBinder <$> (C.lexeme sign <*> C.integerOrFloat)
+  where
+  sign :: P.Parsec String ParseState (Either Integer Double -> Either Integer Double)
+  sign = (P.char '-' >> return (negate +++ negate))
+         <|> (P.char '+' >> return id)
+         <|> return id
 
 parseVarBinder :: P.Parsec String ParseState Binder
 parseVarBinder = VarBinder <$> C.parseIdent