From 7417ce9aeae9b551467ccdb32b354cd4f7569769 Mon Sep 17 00:00:00 2001
From: simonm <unknown>
Date: Mon, 24 Nov 1997 17:50:10 +0000
Subject: [PATCH] [project @ 1997-11-24 17:49:28 by simonm] Pull Maybe and
 Either out of PrelBase into separate modules in an attempt
 to make PrelBase a little smaller.

---
 ghc/lib/ghc/IOBase.lhs       |    1 +
 ghc/lib/ghc/IOHandle.lhs     |    1 +
 ghc/lib/ghc/PrelBase.lhs     |   50 ------------------------------------------
 ghc/lib/ghc/PrelEither.lhs   |   20 +++++++++++++++++
 ghc/lib/ghc/PrelList.lhs     |    1 +
 ghc/lib/ghc/PrelMaybe.lhs    |   44 +++++++++++++++++++++++++++++++++++++
 ghc/lib/ghc/PrelNum.lhs      |    2 +-
 ghc/lib/ghc/PrelRead.lhs     |    2 ++
 ghc/lib/required/IO.lhs      |    2 ++
 ghc/lib/required/Maybe.lhs   |    1 +
 ghc/lib/required/Numeric.lhs |    1 +
 ghc/lib/required/Prelude.lhs |    2 ++
 12 files changed, 76 insertions(+), 51 deletions(-)
 create mode 100644 ghc/lib/ghc/PrelEither.lhs
 create mode 100644 ghc/lib/ghc/PrelMaybe.lhs

diff --git a/ghc/lib/ghc/IOBase.lhs b/ghc/lib/ghc/IOBase.lhs
index d6253db..c920cc8 100644
--- a/ghc/lib/ghc/IOBase.lhs
+++ b/ghc/lib/ghc/IOBase.lhs
@@ -16,6 +16,7 @@ module IOBase where
 import {-# SOURCE #-} Error
 import STBase
 import PrelTup
+import PrelMaybe
 import Addr
 import PackBase	( unpackCString )
 import PrelBase
diff --git a/ghc/lib/ghc/IOHandle.lhs b/ghc/lib/ghc/IOHandle.lhs
index 0d1a9fb..b0c3c81 100644
--- a/ghc/lib/ghc/IOHandle.lhs
+++ b/ghc/lib/ghc/IOHandle.lhs
@@ -23,6 +23,7 @@ import Ix
 import IOBase
 import Unsafe   ( unsafePerformIO )
 import PrelTup
+import PrelMaybe
 import PrelBase
 import GHC
 import Addr
diff --git a/ghc/lib/ghc/PrelBase.lhs b/ghc/lib/ghc/PrelBase.lhs
index 86c9a58..7e780c9 100644
--- a/ghc/lib/ghc/PrelBase.lhs
+++ b/ghc/lib/ghc/PrelBase.lhs
@@ -309,41 +309,6 @@ otherwise 		=  True
 
 %*********************************************************
 %*							*
-\subsection{Type @Maybe@}
-%*							*
-%*********************************************************
-
-\begin{code}
-data  Maybe a  =  Nothing | Just a	deriving (Eq, Ord, Show {- Read -})
-
-maybe :: b -> (a -> b) -> Maybe a -> b
-maybe n f Nothing  = n
-maybe n f (Just x) = f x
-
-instance  Functor Maybe  where
-    map f Nothing       = Nothing
-    map f (Just a)      = Just (f a)
-
-instance  Monad Maybe  where
-    (Just x) >>= k      = k x
-    Nothing  >>= k      = Nothing
-
-    (Just x) >>  k      = k
-    Nothing  >>  k      = Nothing
-
-    return              = Just
-
-instance  MonadZero Maybe  where
-    zero                = Nothing
-
-instance  MonadPlus Maybe  where
-    Nothing ++ ys       = ys
-    xs      ++ ys       = xs
-\end{code}
-
-
-%*********************************************************
-%*							*
 \subsection{The @()@ type}
 %*							*
 %*********************************************************
@@ -391,21 +356,6 @@ instance  Show ()  where
 
 %*********************************************************
 %*							*
-\subsection{Type @Either@}
-%*							*
-%*********************************************************
-
-\begin{code}
-data  Either a b  =  Left a | Right b	deriving (Eq, Ord, Show {- Read -} )
-
-either                  :: (a -> c) -> (b -> c) -> Either a b -> c
-either f g (Left x)     =  f x
-either f g (Right y)    =  g y
-\end{code}
-
-
-%*********************************************************
-%*							*
 \subsection{Type @Ordering@}
 %*							*
 %*********************************************************
diff --git a/ghc/lib/ghc/PrelEither.lhs b/ghc/lib/ghc/PrelEither.lhs
new file mode 100644
index 0000000..71969aa
--- /dev/null
+++ b/ghc/lib/ghc/PrelEither.lhs
@@ -0,0 +1,20 @@
+%
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1997
+%
+\section[PrelEither]{Module @PrelEither@}
+
+The @Either@ Type.
+
+\begin{code}
+{-# OPTIONS -fno-implicit-prelude #-}
+
+module PrelEither where
+
+import PrelBase
+
+data  Either a b  =  Left a | Right b	deriving (Eq, Ord, Show {- Read -} )
+
+either                  :: (a -> c) -> (b -> c) -> Either a b -> c
+either f g (Left x)     =  f x
+either f g (Right y)    =  g y
+\end{code}
diff --git a/ghc/lib/ghc/PrelList.lhs b/ghc/lib/ghc/PrelList.lhs
index 26be5ae..4ed206b 100644
--- a/ghc/lib/ghc/PrelList.lhs
+++ b/ghc/lib/ghc/PrelList.lhs
@@ -24,6 +24,7 @@ module PrelList (
 
 import {-# SOURCE #-} Error ( error )
 import PrelTup
+import PrelMaybe
 import PrelBase
 
 infix  4 `elem`, `notElem`
diff --git a/ghc/lib/ghc/PrelMaybe.lhs b/ghc/lib/ghc/PrelMaybe.lhs
new file mode 100644
index 0000000..974e5de
--- /dev/null
+++ b/ghc/lib/ghc/PrelMaybe.lhs
@@ -0,0 +1,44 @@
+%
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+%
+\section[PrelMaybe]{Module @PrelMaybe@}
+
+The @Maybe@ type.
+
+\begin{code}
+{-# OPTIONS -fno-implicit-prelude #-}
+
+module PrelMaybe where
+
+import PrelBase
+
+data  Maybe a  =  Nothing | Just a	deriving (Eq, Ord, Show {- Read -})
+
+maybe :: b -> (a -> b) -> Maybe a -> b
+maybe n f Nothing  = n
+maybe n f (Just x) = f x
+
+instance  Functor Maybe  where
+    map f Nothing       = Nothing
+    map f (Just a)      = Just (f a)
+
+instance  Monad Maybe  where
+    (Just x) >>= k      = k x
+    Nothing  >>= k      = Nothing
+
+    (Just x) >>  k      = k
+    Nothing  >>  k      = Nothing
+
+    return              = Just
+
+instance  MonadZero Maybe  where
+    zero                = Nothing
+
+instance  MonadPlus Maybe  where
+    Nothing ++ ys       = ys
+    xs      ++ ys       = xs
+\end{code}
+
+
+
+
diff --git a/ghc/lib/ghc/PrelNum.lhs b/ghc/lib/ghc/PrelNum.lhs
index 72e6d4a..041214d 100644
--- a/ghc/lib/ghc/PrelNum.lhs
+++ b/ghc/lib/ghc/PrelNum.lhs
@@ -23,6 +23,7 @@ import PrelBase
 import GHC
 import {-# SOURCE #-} Error ( error )
 import PrelList
+import PrelMaybe
 
 import ArrBase	( Array, array, (!) )
 import Unsafe   ( unsafePerformIO )
@@ -1185,7 +1186,6 @@ integerLogBase b i =
 	in  doDiv (i `div` (b^l)) l
 \end{code}
 
-
 %*********************************************************
 %*							*
 \subsection{Numeric primops}
diff --git a/ghc/lib/ghc/PrelRead.lhs b/ghc/lib/ghc/PrelRead.lhs
index f3a064f..60917b3 100644
--- a/ghc/lib/ghc/PrelRead.lhs
+++ b/ghc/lib/ghc/PrelRead.lhs
@@ -15,6 +15,8 @@ import {-# SOURCE #-} Error ( error )
 import PrelNum
 import PrelList
 import PrelTup
+import PrelMaybe
+import PrelEither
 import PrelBase
 \end{code}
 
diff --git a/ghc/lib/required/IO.lhs b/ghc/lib/required/IO.lhs
index abf28ec..4e058d3 100644
--- a/ghc/lib/required/IO.lhs
+++ b/ghc/lib/required/IO.lhs
@@ -40,6 +40,8 @@ import ArrBase		( MutableByteArray(..), newCharArray )
 import IOHandle		-- much of the real stuff is in here
 import PackBase		( unpackNBytesST )
 import PrelBase
+import PrelMaybe
+import PrelEither
 import GHC
 import Addr
 
diff --git a/ghc/lib/required/Maybe.lhs b/ghc/lib/required/Maybe.lhs
index 2c663aa..40b130f 100644
--- a/ghc/lib/required/Maybe.lhs
+++ b/ghc/lib/required/Maybe.lhs
@@ -23,6 +23,7 @@ module Maybe
 import Error	( error )
 import Monad	( filter )
 import PrelList
+import PrelMaybe
 import PrelBase
 \end{code}
 
diff --git a/ghc/lib/required/Numeric.lhs b/ghc/lib/required/Numeric.lhs
index 34b26d1..2dd49a3 100644
--- a/ghc/lib/required/Numeric.lhs
+++ b/ghc/lib/required/Numeric.lhs
@@ -32,6 +32,7 @@ module Numeric
 	) where
 
 import PrelBase
+import PrelMaybe
 import ArrBase
 import PrelNum
 import PrelRead
diff --git a/ghc/lib/required/Prelude.lhs b/ghc/lib/required/Prelude.lhs
index 088bc2b..92d173f 100644
--- a/ghc/lib/required/Prelude.lhs
+++ b/ghc/lib/required/Prelude.lhs
@@ -67,6 +67,8 @@ import PrelIO
 import PrelRead
 import PrelNum
 import PrelTup
+import PrelMaybe
+import PrelEither
 import Monad
 import Maybe
 import Error	( error )
-- 
1.7.10.4