[project @ 2005-03-14 15:22:51 by simonmar]

[ghc-base.git] / Data / Char.hs

diff --git a/Data/Char.hs b/Data/Char.hs
index e7d7b72..2ec1e66 100644 (file)
--- a/Data/Char.hs
+++ b/Data/Char.hs
@@ -1,12 +1,12 @@
-{-# OPTIONS -fno-implicit-prelude #-}
+{-# OPTIONS_GHC -fno-implicit-prelude #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Char
 -- Copyright   :  (c) The University of Glasgow 2001
--- License     :  BSD-style (see the file libraries/core/LICENSE)
+-- License     :  BSD-style (see the file libraries/base/LICENSE)
 -- 
 -- Maintainer  :  libraries@haskell.org
--- Stability   :  provisional
+-- Stability   :  stable
 -- Portability :  portable
 --
 -- The Char type and associated operations.
@@ -17,23 +17,35 @@ module Data.Char
     (
       Char
 
-    , isAscii, isLatin1, isControl
-    , isPrint, isSpace,  isUpper
-    , isLower, isAlpha,  isDigit
-    , isOctDigit, isHexDigit, isAlphaNum  -- :: Char -> Bool
+    , String
+
+    -- * Character classification
+    -- | Unicode characters are divided into letters, numbers, marks,
+    -- punctuation, symbols, separators (including spaces) and others
+    -- (including control characters).
+    , isAscii, isLatin1, isControl, isSpace
+    , isLower, isUpper,  isAlpha,   isAlphaNum, isPrint
+    , isDigit, isOctDigit, isHexDigit
+    , isAsciiUpper, isAsciiLower
+    , isLetter, isMark, isNumber, isPunctuation, isSymbol, isSeparator
+
+    , GeneralCategory(..), generalCategory
 
-    , toUpper, toLower  -- :: Char -> Char
+    -- * Case conversion
+    , toUpper, toLower, toTitle  -- :: Char -> Char
 
+    -- * Single digit characters
     , digitToInt        -- :: Char -> Int
     , intToDigit        -- :: Int  -> Char
 
+    -- * Numeric representations
     , ord               -- :: Char -> Int
     , chr               -- :: Int  -> Char
-    , readLitChar       -- :: ReadS Char 
+
+    -- * String representations
     , showLitChar       -- :: Char -> ShowS
     , lexLitChar       -- :: ReadS String
-
-    , String
+    , readLitChar       -- :: ReadS Char 
 
      -- Implementation checked wrt. Haskell 98 lib report, 1/99.
     ) where
@@ -42,9 +54,27 @@ module Data.Char
 import GHC.Base
 import GHC.Show
 import GHC.Read (readLitChar, lexLitChar)
+import GHC.Unicode
+import GHC.Num
 #endif
 
 #ifdef __HUGS__
-isLatin1 c = True
+import Hugs.Char
+#endif
+
+#ifdef __NHC__
+import Prelude
+import Prelude(Char,String)
+import Char
 #endif
 
+-- | Convert a single digit 'Char' to the corresponding 'Int'.  
+-- This function fails unless its argument satisfies 'isHexDigit',
+-- but recognises both upper and lower-case hexadecimal digits
+-- (i.e. @\'0\'@..@\'9\'@, @\'a\'@..@\'f\'@, @\'A\'@..@\'F\'@).
+digitToInt :: Char -> Int
+digitToInt c
+ | isDigit c           =  ord c - ord '0'
+ | c >= 'a' && c <= 'f' =  ord c - ord 'a' + 10
+ | c >= 'A' && c <= 'F' =  ord c - ord 'A' + 10
+ | otherwise           =  error ("Char.digitToInt: not a digit " ++ show c) -- sigh