X-Git-Url: http://git.megacz.com/?p=ghc-base.git;a=blobdiff_plain;f=Prelude.hs;h=4c183ae38c9ad44a22a25c4bba5fa9149066cb62;hp=7ad635530ef40e3a299398ffba08853f35a5baab;hb=HEAD;hpb=1172e0e4b9640aa96095e31bcdc854cc55b54e34

diff --git a/Prelude.hs b/Prelude.hs
index 7ad6355..4c183ae 100644
--- a/Prelude.hs
+++ b/Prelude.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS -fno-implicit-prelude #-}
+{-# LANGUAGE CPP, NoImplicitPrelude, BangPatterns #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Prelude
@@ -6,7 +7,7 @@
 -- License     :  BSD-style (see the file libraries/base/LICENSE)
 -- 
 -- Maintainer  :  libraries@haskell.org
--- Stability   :  provisional
+-- Stability   :  stable
 -- Portability :  portable
 --
 -- The Prelude: a standard module imported by default into all Haskell
@@ -17,32 +18,49 @@
 
 module Prelude (
 
-    -- * Basic data types
+    -- * Standard types, classes and related functions
+
+    -- ** Basic data types
     Bool(False, True),
+    (&&), (||), not, otherwise,
+
     Maybe(Nothing, Just),
+    maybe,
+
     Either(Left, Right),
+    either,
+
     Ordering(LT, EQ, GT),
-    Char, String, Int, Integer, Float, Double, IO,
-    Rational,
+    Char, String,
+
+    -- *** Tuples
+    fst, snd, curry, uncurry,
+
 #if defined(__NHC__)
-    []((:), []),	-- Not legal Haskell 98;
-			-- ... available through built-in syntax
-    module Data.Tuple,	-- Includes tuple types
-    ()(..),		-- Not legal Haskell 98
-    (->),		-- ... available through built-in syntax
+    []((:), []),        -- Not legal Haskell 98;
+                        -- ... available through built-in syntax
+    module Data.Tuple,  -- Includes tuple types
+    ()(..),             -- Not legal Haskell 98
+    (->),               -- ... available through built-in syntax
 #endif
 #ifdef __HUGS__
-    (:),		-- Not legal Haskell 98
+    (:),                -- Not legal Haskell 98
 #endif
-    
-    -- * Basic type classes
+
+    -- ** Basic type classes
     Eq((==), (/=)),
     Ord(compare, (<), (<=), (>=), (>), max, min),
     Enum(succ, pred, toEnum, fromEnum, enumFrom, enumFromThen,
          enumFromTo, enumFromThenTo),
     Bounded(minBound, maxBound),
 
-    -- * Numeric type classes
+    -- ** Numbers
+
+    -- *** Numeric types
+    Int, Integer, Float, Double,
+    Rational,
+
+    -- *** Numeric type classes
     Num((+), (-), (*), negate, abs, signum, fromInteger),
     Real(toRational),
     Integral(quot, rem, div, mod, quotRem, divMod, toInteger),
@@ -54,28 +72,58 @@ module Prelude (
               encodeFloat, exponent, significand, scaleFloat, isNaN,
               isInfinite, isDenormalized, isIEEE, isNegativeZero, atan2),
 
+    -- *** Numeric functions
+    subtract, even, odd, gcd, lcm, (^), (^^),
+    fromIntegral, realToFrac,
+
+    -- ** Monads and functors
+    Monad((>>=), (>>), return, fail),
+    Functor(fmap),
+    mapM, mapM_, sequence, sequence_, (=<<),
+
+    -- ** Miscellaneous functions
+    id, const, (.), flip, ($), until,
+    asTypeOf, error, undefined,
+    seq, ($!),
+
     -- * List operations
-    map, (++), filter, concat,
-    head, last, tail, init, null, length, (!!), 
-    foldl, foldl1, scanl, scanl1, foldr, foldr1, scanr, scanr1,
+    map, (++), filter,
+    head, last, tail, init, null, length, (!!),
+    reverse,
+    -- ** Reducing lists (folds)
+    foldl, foldl1, foldr, foldr1,
+    -- *** Special folds
+    and, or, any, all,
+    sum, product,
+    concat, concatMap,
+    maximum, minimum,
+    -- ** Building lists
+    -- *** Scans
+    scanl, scanl1, scanr, scanr1,
+    -- *** Infinite lists
     iterate, repeat, replicate, cycle,
+    -- ** Sublists
     take, drop, splitAt, takeWhile, dropWhile, span, break,
-    reverse, and, or,
-    any, all, elem, notElem, lookup,
-    maximum, minimum, concatMap,
+    -- ** Searching lists
+    elem, notElem, lookup,
+    -- ** Zipping and unzipping lists
     zip, zip3, zipWith, zipWith3, unzip, unzip3,
-
+    -- ** Functions on strings
     lines, words, unlines, unwords,
-    sum, product,
 
     -- * Converting to and from @String@
-    ReadS, ShowS,
-    Read(readsPrec, readList),
+    -- ** Converting to @String@
+    ShowS,
     Show(showsPrec, showList, show),
-    reads, shows, read, lex, 
-    showChar, showString, readParen, showParen,
-    
+    shows,
+    showChar, showString, showParen,
+    -- ** Converting from @String@
+    ReadS,
+    Read(readsPrec, readList),
+    reads, readParen, read, lex,
+
     -- * Basic Input and output
+    IO,
     -- ** Simple I\/O operations
     -- All I/O functions defined here are character oriented.  The
     -- treatment of the newline character will vary on different systems.
@@ -92,48 +140,31 @@ module Prelude (
     FilePath,
     readFile, writeFile, appendFile, readIO, readLn,
     -- ** Exception handling in the I\/O monad
-    IOError, ioError, userError, catch,
-
-    -- * Monads
-    Monad((>>=), (>>), return, fail),
-    Functor(fmap),
-    mapM, mapM_, sequence, sequence_, (=<<),
-
-    -- * Miscellaneous functions
-    maybe, either,
-    (&&), (||), not, otherwise,
-    subtract, even, odd, gcd, lcm, (^), (^^), 
-    fromIntegral, realToFrac,
-    fst, snd, curry, uncurry,
-    id, const, (.), flip, ($), until,
-    asTypeOf, error, undefined,
-    seq, ($!)
+    IOError, ioError, userError, catch
 
   ) where
 
 #ifndef __HUGS__
 import Control.Monad
 import System.IO
-import Text.Read
-import Text.Show
+import System.IO.Error
 import Data.List
 import Data.Either
 import Data.Maybe
-import Data.Bool
 import Data.Tuple
 #endif
 
 #ifdef __GLASGOW_HASKELL__
 import GHC.Base
-import GHC.IOBase
-import GHC.Exception
-import GHC.Read
+-- import GHC.IO
+-- import GHC.IO.Exception
+import Text.Read
 import GHC.Enum
 import GHC.Num
 import GHC.Real
 import GHC.Float
 import GHC.Show
-import GHC.Err   ( error, undefined )
+import GHC.Err   ( undefined )
 #endif
 
 #ifdef __HUGS__
@@ -142,12 +173,23 @@ import Hugs.Prelude
 
 #ifndef __HUGS__
 infixr 0 $!
-
+#endif
 
 -- -----------------------------------------------------------------------------
 -- Miscellaneous functions
 
+-- | Strict (call-by-value) application, defined in terms of 'seq'.
 ($!)    :: (a -> b) -> a -> b
+#ifdef __GLASGOW_HASKELL__
+f $! x  = let !vx = x in f vx  -- see #2273
+#elif !defined(__HUGS__)
 f $! x  = x `seq` f x
 #endif
 
+#ifdef __HADDOCK__
+-- | The value of @'seq' a b@ is bottom if @a@ is bottom, and otherwise
+-- equal to @b@.  'seq' is usually introduced to improve performance by
+-- avoiding unneeded laziness.
+seq :: a -> b -> b
+seq _ y = y
+#endif