X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Prelude.hs;h=840c2ca5b965bc614966e8038e968e86b1067157;hb=297d7e3e4ce4950125fd4b6e3bff9d7f6afbfbc6;hp=2fb0bafeabe26f2435e2a8ba525079fe613c737b;hpb=5f4a737d076331b7b621e8c02fd0e39ea80af348;p=ghc-base.git

diff --git a/Prelude.hs b/Prelude.hs
index 2fb0baf..840c2ca 100644
--- a/Prelude.hs
+++ b/Prelude.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fno-implicit-prelude #-}
+{-# OPTIONS_GHC -fno-implicit-prelude #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Prelude
@@ -6,7 +6,7 @@
 -- 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
@@ -17,15 +17,25 @@
 
 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,
-#if defined(__GLASGOW_HASKELL__) || defined(__NHC__)
-	-- Restore export of (:) until we get to 5.05
+    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
@@ -36,14 +46,20 @@ module Prelude (
     (:),		-- 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),
@@ -55,50 +71,75 @@ 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,
+    map, (++), filter,
     head, last, tail, init, null, length, (!!), 
-    foldl, foldl1, scanl, scanl1, foldr, foldr1, scanr, scanr1,
+    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, 
     
-    -- * Simple I\/O operations
-    ioError, userError, catch,
-    FilePath, IOError,
+    -- * 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.
+    -- For example, two characters of input, return and linefeed, may
+    -- read as a single newline character.  These functions cannot be
+    -- used portably for binary I/O.
+    -- *** Output functions
     putChar,
     putStr, putStrLn, print,
+    -- *** Input functions
     getChar,
     getLine, getContents, interact,
+    -- *** Files
+    FilePath,
     readFile, writeFile, appendFile, readIO, readLn,
-
-    -- * 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, ($), until,
-    asTypeOf, error, undefined,
-    seq, ($!)
+    -- ** Exception handling in the I\/O monad
+    IOError, ioError, userError, catch
 
   ) where
 
@@ -112,6 +153,8 @@ import Data.Either
 import Data.Maybe
 import Data.Bool
 import Data.Tuple
+import Data.Eq
+import Data.Ord
 #endif
 
 #ifdef __GLASGOW_HASKELL__
@@ -124,7 +167,6 @@ import GHC.Num
 import GHC.Real
 import GHC.Float
 import GHC.Show
-import GHC.Conc
 import GHC.Err   ( error, undefined )
 #endif
 
@@ -135,11 +177,18 @@ import Hugs.Prelude
 #ifndef __HUGS__
 infixr 0 $!
 
-
 -- -----------------------------------------------------------------------------
 -- Miscellaneous functions
 
+-- | Strict (call-by-value) application, defined in terms of 'seq'.
 ($!)    :: (a -> b) -> a -> b
 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