A decimal exponent is not required for a number

This ensures that a decimal exponent is optional

Author: MaybeJustJames

src/Parsing/String/Basic.purs

@@ -120,7 +120,7 @@ number =
 numberRegex :: forall m. ParserT String m String
 numberRegex = either unsafeCrashWith identity $ regex pattern mempty
   where
-  pattern = "[+-]?[0-9]*(\\.[0-9]*)?([eE][+-]?[0-9]*(\\.[0-9]*))?"
+  pattern = "[+-]?[0-9]*(\\.[0-9]*)?([eE][+-]?[0-9]*(\\.[0-9]*)?)?"
 
 -- | Parser based on the __Data.Int.fromString__ function.
 -- |

test/Main.purs

@@ -726,6 +726,11 @@ main = do
     , expected: Right (-0.3)
     }
 
+  assertEqual' "number xEy"
+    { actual: runParser "2e1" number
+    , expected: Right 20.0
+    }
+
   -- test from issue #73
   assertEqual' "number 2"
     { actual: runParser "0.7531531167929774" number