From 2a36bef39a3fca473b6a83d169dfba09588fe372 Mon Sep 17 00:00:00 2001
From: HuStmpHrrr <fdhzs2010@hotmail.com>
Date: Wed, 17 Feb 2016 18:39:05 -0500
Subject: [PATCH] add sepBy' and sepBy1' combinators

---
 Text/Parsec/Combinator.hs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Text/Parsec/Combinator.hs b/Text/Parsec/Combinator.hs
index de5b619e..e1e3d610 100644
--- a/Text/Parsec/Combinator.hs
+++ b/Text/Parsec/Combinator.hs
@@ -20,6 +20,7 @@ module Text.Parsec.Combinator
     , skipMany1
     , many1
     , sepBy, sepBy1
+    , sepBy', sepBy1'
     , endBy, endBy1
     , sepEndBy, sepEndBy1
     , chainl, chainl1
@@ -119,6 +120,20 @@ sepBy1 p sep        = do{ x <- p
                         ; return (x:xs)
                         }
 
+sepBy' :: (Stream s m t) => ParsecT s u m a -> ParsecT s u m sep -> ParsecT s u m [a]
+sepBy' p sep        = sepBy1' p sep <|> return []
+
+sepBy1' :: (Stream s m t) => ParsecT s u m a -> ParsecT s u m sep -> ParsecT s u m [a]
+sepBy1' p sep       = do{ x <- p
+                        ; xs <- piter []
+                        ; return $ x:reverse xs
+                        }
+    where piter acc = do{ m <- optionMaybe sep
+                        ; case m of
+                            Nothing -> return acc
+                            Just _  -> do{ x' <- p; piter $ x':acc }
+                        }
+
 
 -- | @sepEndBy1 p sep@ parses /one/ or more occurrences of @p@,
 -- separated and optionally ended by @sep@. Returns a list of values