From 93052875e06a4e73989a5c1eb75292d14330ac98 Mon Sep 17 00:00:00 2001
From: Willem Van Onsem <vanonsem.willem@gmail.com>
Date: Tue, 29 Dec 2020 17:32:22 +0100
Subject: [PATCH 1/2] make functions to parse files with stateful parsers

---
 src/Text/Parsec/ByteString.hs      | 24 ++++++++++++++++++------
 src/Text/Parsec/ByteString/Lazy.hs | 26 +++++++++++++++++++-------
 src/Text/Parsec/String.hs          | 25 +++++++++++++++++++------
 src/Text/Parsec/Text.hs            | 28 +++++++++++++++++++---------
 src/Text/Parsec/Text/Lazy.hs       | 28 +++++++++++++++++++---------
 5 files changed, 94 insertions(+), 37 deletions(-)

diff --git a/src/Text/Parsec/ByteString.hs b/src/Text/Parsec/ByteString.hs
index e65dee14..2840937c 100644
--- a/src/Text/Parsec/ByteString.hs
+++ b/src/Text/Parsec/ByteString.hs
@@ -15,7 +15,7 @@
 -----------------------------------------------------------------------------
 
 module Text.Parsec.ByteString
-    ( Parser, GenParser, parseFromFile
+    ( Parser, ParserU, GenParser, parseFromFile, parseFromFile'
     ) where
 
 import Text.Parsec.Error
@@ -23,9 +23,24 @@ import Text.Parsec.Prim
 
 import qualified Data.ByteString.Char8 as C
 
-type Parser = Parsec C.ByteString ()
+type ParserU u = Parsec C.ByteString u
+type Parser = ParserU ()
 type GenParser t st = Parsec C.ByteString st
 
+
+-- | @parseFromFile' p u filePath@ runs a strict bytestring parser @p@ on the
+-- input read from @filePath@ using 'ByteString.Char8.readFile' with start state @u@.
+-- Returns either a 'ParseError' ('Left') or a value of type @a@ ('Right').
+--
+-- >  main    = do{ result <- parseFromFile' numbers () "digits.txt"
+-- >              ; case result of
+-- >                  Left err  -> print err
+-- >                  Right xs  -> print (sum xs)
+-- >              }
+parseFromFile' :: ParserU u a -> u -> FilePath -> IO (Either ParseError a)
+parseFromFile' p u fname = runP p u fname <$> C.readFile fname
+
+
 -- | @parseFromFile p filePath@ runs a strict bytestring parser @p@ on the
 -- input read from @filePath@ using 'ByteString.Char8.readFile'. Returns either a 'ParseError'
 -- ('Left') or a value of type @a@ ('Right').
@@ -35,8 +50,5 @@ type GenParser t st = Parsec C.ByteString st
 -- >                  Left err  -> print err
 -- >                  Right xs  -> print (sum xs)
 -- >              }
-
 parseFromFile :: Parser a -> FilePath -> IO (Either ParseError a)
-parseFromFile p fname
-    = do input <- C.readFile fname
-         return (runP p () fname input)
+parseFromFile = (`parseFromFile'` ())
diff --git a/src/Text/Parsec/ByteString/Lazy.hs b/src/Text/Parsec/ByteString/Lazy.hs
index 2a457814..5dfcfd10 100644
--- a/src/Text/Parsec/ByteString/Lazy.hs
+++ b/src/Text/Parsec/ByteString/Lazy.hs
@@ -15,7 +15,7 @@
 -----------------------------------------------------------------------------
 
 module Text.Parsec.ByteString.Lazy
-    ( Parser, GenParser, parseFromFile
+    ( Parser, ParserU, GenParser, parseFromFile, parseFromFile'
     ) where
 
 import Text.Parsec.Error
@@ -23,10 +23,25 @@ import Text.Parsec.Prim
 
 import qualified Data.ByteString.Lazy.Char8 as C
 
-type Parser = Parsec C.ByteString ()
+type ParserU u = Parsec C.ByteString u
+type Parser = ParserU ()
 type GenParser t st = Parsec C.ByteString st
 
--- | @parseFromFile p filePath@ runs a lazy bytestring parser @p@ on the
+
+-- | @parseFromFile' p u filePath@ runs a strict bytestring parser @p@ on the
+-- input read from @filePath@ using 'ByteString.Lazy.Char8.readFile' with start state @u@.
+-- Returns either a 'ParseError' ('Left') or a value of type @a@ ('Right').
+--
+-- >  main    = do{ result <- parseFromFile' numbers () "digits.txt"
+-- >              ; case result of
+-- >                  Left err  -> print err
+-- >                  Right xs  -> print (sum xs)
+-- >              }
+parseFromFile' :: ParserU u a -> u -> FilePath -> IO (Either ParseError a)
+parseFromFile' p u fname = runP p u fname <$> C.readFile fname
+
+
+-- | @parseFromFile p filePath@ runs a strict bytestring parser @p@ on the
 -- input read from @filePath@ using 'ByteString.Lazy.Char8.readFile'. Returns either a 'ParseError'
 -- ('Left') or a value of type @a@ ('Right').
 --
@@ -35,8 +50,5 @@ type GenParser t st = Parsec C.ByteString st
 -- >                  Left err  -> print err
 -- >                  Right xs  -> print (sum xs)
 -- >              }
-
 parseFromFile :: Parser a -> FilePath -> IO (Either ParseError a)
-parseFromFile p fname
-    = do input <- C.readFile fname
-         return (runP p () fname input)
+parseFromFile = (`parseFromFile'` ())
diff --git a/src/Text/Parsec/String.hs b/src/Text/Parsec/String.hs
index 67efa537..e1ecc396 100644
--- a/src/Text/Parsec/String.hs
+++ b/src/Text/Parsec/String.hs
@@ -15,16 +15,31 @@
 -----------------------------------------------------------------------------
 
 module Text.Parsec.String
-    ( Parser, GenParser, parseFromFile
+    ( Parser, ParserU, GenParser, parseFromFile, parseFromFile'
     ) where
 
 import Text.Parsec.Error
 import Text.Parsec.Prim
 
-type Parser = Parsec String ()
+type ParserU u = Parsec String u
+type Parser = ParserU ()
 type GenParser tok st = Parsec [tok] st
 
--- | @parseFromFile p filePath@ runs a string parser @p@ on the
+
+-- | @parseFromFile' p u filePath@ runs a strict bytestring parser @p@ on the
+-- input read from @filePath@ using 'Prelude.readFile' with start state @u@.
+-- Returns either a 'ParseError' ('Left') or a value of type @a@ ('Right').
+--
+-- >  main    = do{ result <- parseFromFile' numbers () "digits.txt"
+-- >              ; case result of
+-- >                  Left err  -> print err
+-- >                  Right xs  -> print (sum xs)
+-- >              }
+parseFromFile' :: ParserU u a -> u -> FilePath -> IO (Either ParseError a)
+parseFromFile' p u fname = runP p u fname <$> readFile fname
+
+
+-- | @parseFromFile p filePath@ runs a strict bytestring parser @p@ on the
 -- input read from @filePath@ using 'Prelude.readFile'. Returns either a 'ParseError'
 -- ('Left') or a value of type @a@ ('Right').
 --
@@ -34,6 +49,4 @@ type GenParser tok st = Parsec [tok] st
 -- >                  Right xs  -> print (sum xs)
 -- >              }
 parseFromFile :: Parser a -> FilePath -> IO (Either ParseError a)
-parseFromFile p fname
-    = do input <- readFile fname
-         return (runP p () fname input)
+parseFromFile = (`parseFromFile'` ())
diff --git a/src/Text/Parsec/Text.hs b/src/Text/Parsec/Text.hs
index 0e609686..b346d7bd 100644
--- a/src/Text/Parsec/Text.hs
+++ b/src/Text/Parsec/Text.hs
@@ -15,7 +15,7 @@
 -----------------------------------------------------------------------------
 
 module Text.Parsec.Text
-    ( Parser, GenParser, parseFromFile
+    ( Parser, ParserU, GenParser, parseFromFile, parseFromFile'
     ) where
 
 import qualified Data.Text as Text
@@ -23,10 +23,25 @@ import Text.Parsec.Prim
 import Text.Parsec.Error
 import Data.Text.IO as T
 
-type Parser = Parsec Text.Text ()
+type ParserU u = Parsec Text.Text u
+type Parser = ParserU ()
 type GenParser st = Parsec Text.Text st
 
--- | @parseFromFile p filePath@ runs a strict text parser @p@ on the
+
+-- | @parseFromFile' p u filePath@ runs a strict bytestring parser @p@ on the
+-- input read from @filePath@ using 'Data.Text.IO.readFile' with start state @u@.
+-- Returns either a 'ParseError' ('Left') or a value of type @a@ ('Right').
+--
+-- >  main    = do{ result <- parseFromFile' numbers () "digits.txt"
+-- >              ; case result of
+-- >                  Left err  -> print err
+-- >                  Right xs  -> print (sum xs)
+-- >              }
+parseFromFile' :: ParserU u a -> u -> FilePath -> IO (Either ParseError a)
+parseFromFile' p u fname = runP p u fname <$> T.readFile fname
+
+
+-- | @parseFromFile p filePath@ runs a strict bytestring parser @p@ on the
 -- input read from @filePath@ using 'Data.Text.IO.readFile'. Returns either a 'ParseError'
 -- ('Left') or a value of type @a@ ('Right').
 --
@@ -35,10 +50,5 @@ type GenParser st = Parsec Text.Text st
 -- >                  Left err  -> print err
 -- >                  Right xs  -> print (sum xs)
 -- >              }
---
--- @since 3.1.14.0
-
 parseFromFile :: Parser a -> FilePath -> IO (Either ParseError a)
-parseFromFile p fname
-    = do input <- T.readFile fname
-         return (runP p () fname input)
+parseFromFile = (`parseFromFile'` ())
diff --git a/src/Text/Parsec/Text/Lazy.hs b/src/Text/Parsec/Text/Lazy.hs
index 3cddb675..789881bd 100644
--- a/src/Text/Parsec/Text/Lazy.hs
+++ b/src/Text/Parsec/Text/Lazy.hs
@@ -15,7 +15,7 @@
 -----------------------------------------------------------------------------
 
 module Text.Parsec.Text.Lazy
-    ( Parser, GenParser, parseFromFile
+    ( Parser, ParserU, GenParser, parseFromFile, parseFromFile'
     ) where
 
 import qualified Data.Text.Lazy as Text
@@ -23,10 +23,25 @@ import Text.Parsec.Prim
 import Text.Parsec.Error
 import Data.Text.Lazy.IO as TL
 
-type Parser = Parsec Text.Text ()
+type ParserU u = Parsec Text.Text u
+type Parser = ParserU ()
 type GenParser st = Parsec Text.Text st
 
--- | @parseFromFile p filePath@ runs a strict text parser @p@ on the
+
+-- | @parseFromFile' p u filePath@ runs a strict bytestring parser @p@ on the
+-- input read from @filePath@ using 'Data.Text.Lazy.IO.readFile' with start state @u@.
+-- Returns either a 'ParseError' ('Left') or a value of type @a@ ('Right').
+--
+-- >  main    = do{ result <- parseFromFile' numbers () "digits.txt"
+-- >              ; case result of
+-- >                  Left err  -> print err
+-- >                  Right xs  -> print (sum xs)
+-- >              }
+parseFromFile' :: ParserU u a -> u -> FilePath -> IO (Either ParseError a)
+parseFromFile' p u fname = runP p u fname <$> TL.readFile fname
+
+
+-- | @parseFromFile p filePath@ runs a strict bytestring parser @p@ on the
 -- input read from @filePath@ using 'Data.Text.Lazy.IO.readFile'. Returns either a 'ParseError'
 -- ('Left') or a value of type @a@ ('Right').
 --
@@ -35,10 +50,5 @@ type GenParser st = Parsec Text.Text st
 -- >                  Left err  -> print err
 -- >                  Right xs  -> print (sum xs)
 -- >              }
---
--- @since 3.1.14.0
-
 parseFromFile :: Parser a -> FilePath -> IO (Either ParseError a)
-parseFromFile p fname
-    = do input <- TL.readFile fname
-         return (runP p () fname input)
+parseFromFile = (`parseFromFile'` ())

From c874511df6c50e5f99bd021d4b81ada5e9a4fc94 Mon Sep 17 00:00:00 2001
From: Willem Van Onsem <vanonsem.willem@gmail.com>
Date: Tue, 29 Dec 2020 20:09:33 +0100
Subject: [PATCH 2/2] conditional import of (<$>)

---
 src/Text/Parsec/ByteString.hs      | 5 +++++
 src/Text/Parsec/ByteString/Lazy.hs | 5 +++++
 src/Text/Parsec/String.hs          | 5 +++++
 src/Text/Parsec/Text.hs            | 5 +++++
 src/Text/Parsec/Text/Lazy.hs       | 5 +++++
 5 files changed, 25 insertions(+)

diff --git a/src/Text/Parsec/ByteString.hs b/src/Text/Parsec/ByteString.hs
index 2840937c..74936e45 100644
--- a/src/Text/Parsec/ByteString.hs
+++ b/src/Text/Parsec/ByteString.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 -----------------------------------------------------------------------------
@@ -18,6 +19,10 @@ module Text.Parsec.ByteString
     ( Parser, ParserU, GenParser, parseFromFile, parseFromFile'
     ) where
 
+#if __GLASGOW_HASKELL__ < 710
+import Data.Functor((<$>))
+#endif
+
 import Text.Parsec.Error
 import Text.Parsec.Prim
 
diff --git a/src/Text/Parsec/ByteString/Lazy.hs b/src/Text/Parsec/ByteString/Lazy.hs
index 5dfcfd10..f1d1f28d 100644
--- a/src/Text/Parsec/ByteString/Lazy.hs
+++ b/src/Text/Parsec/ByteString/Lazy.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 -----------------------------------------------------------------------------
@@ -18,6 +19,10 @@ module Text.Parsec.ByteString.Lazy
     ( Parser, ParserU, GenParser, parseFromFile, parseFromFile'
     ) where
 
+#if __GLASGOW_HASKELL__ < 710
+import Data.Functor((<$>))
+#endif
+
 import Text.Parsec.Error
 import Text.Parsec.Prim
 
diff --git a/src/Text/Parsec/String.hs b/src/Text/Parsec/String.hs
index e1ecc396..c1f5de08 100644
--- a/src/Text/Parsec/String.hs
+++ b/src/Text/Parsec/String.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 -----------------------------------------------------------------------------
@@ -18,6 +19,10 @@ module Text.Parsec.String
     ( Parser, ParserU, GenParser, parseFromFile, parseFromFile'
     ) where
 
+#if __GLASGOW_HASKELL__ < 710
+import Data.Functor((<$>))
+#endif
+
 import Text.Parsec.Error
 import Text.Parsec.Prim
 
diff --git a/src/Text/Parsec/Text.hs b/src/Text/Parsec/Text.hs
index b346d7bd..04de919f 100644
--- a/src/Text/Parsec/Text.hs
+++ b/src/Text/Parsec/Text.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 -----------------------------------------------------------------------------
@@ -18,6 +19,10 @@ module Text.Parsec.Text
     ( Parser, ParserU, GenParser, parseFromFile, parseFromFile'
     ) where
 
+#if __GLASGOW_HASKELL__ < 710
+import Data.Functor((<$>))
+#endif
+
 import qualified Data.Text as Text
 import Text.Parsec.Prim
 import Text.Parsec.Error
diff --git a/src/Text/Parsec/Text/Lazy.hs b/src/Text/Parsec/Text/Lazy.hs
index 789881bd..bc50c409 100644
--- a/src/Text/Parsec/Text/Lazy.hs
+++ b/src/Text/Parsec/Text/Lazy.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 -----------------------------------------------------------------------------
@@ -18,6 +19,10 @@ module Text.Parsec.Text.Lazy
     ( Parser, ParserU, GenParser, parseFromFile, parseFromFile'
     ) where
 
+#if __GLASGOW_HASKELL__ < 710
+import Data.Functor((<$>))
+#endif
+
 import qualified Data.Text.Lazy as Text
 import Text.Parsec.Prim
 import Text.Parsec.Error