-{-# OPTIONS -fno-implicit-prelude #-}
+{-# LANGUAGE CPP, NoImplicitPrelude #-}
+
-----------------------------------------------------------------------------
-- |
-- 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.
--
-----------------------------------------------------------------------------
-module Data.Char
+module Data.Char
(
Char
- , isAscii, isLatin1, isControl
- , isPrint, isSpace, isUpper
- , isLower, isAlpha, isDigit
- , isOctDigit, isHexDigit, isAlphaNum -- :: Char -> Bool
+ -- * Character classification
+ -- | Unicode characters are divided into letters, numbers, marks,
+ -- punctuation, symbols, separators (including spaces) and others
+ -- (including control characters).
+ , isControl, isSpace
+ , isLower, isUpper, isAlpha, isAlphaNum, isPrint
+ , isDigit, isOctDigit, isHexDigit
+ , isLetter, isMark, isNumber, isPunctuation, isSymbol, isSeparator
+
+ -- ** Subranges
+ , isAscii, isLatin1
+ , isAsciiUpper, isAsciiLower
- , toUpper, toLower -- :: Char -> Char
+ -- ** Unicode general categories
+ , GeneralCategory(..), generalCategory
+ -- * 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
- , showLitChar -- :: Char -> ShowS
- , lexLitChar -- :: ReadS String
- , String
+ -- * String representations
+ , showLitChar -- :: Char -> ShowS
+ , lexLitChar -- :: ReadS String
+ , readLitChar -- :: ReadS Char
-- Implementation checked wrt. Haskell 98 lib report, 1/99.
) where
#ifdef __GLASGOW_HASKELL__
import GHC.Base
+import GHC.Arr (Ix)
+import GHC.Real (fromIntegral)
import GHC.Show
-import GHC.Read (readLitChar, lexLitChar)
+import GHC.Read (Read, readLitChar, lexLitChar)
+import GHC.Unicode
+import GHC.Num
+import GHC.Enum
+#endif
+
+#ifdef __HUGS__
+import Hugs.Prelude (Ix)
+import Hugs.Char
+#endif
+
+#ifdef __NHC__
+import Prelude
+import Prelude(Char,String)
+import Char
+import Ix
+import NHC.FFI (CInt)
+foreign import ccall unsafe "WCsubst.h u_gencat" wgencat :: CInt -> CInt
+#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
+
+#ifndef __GLASGOW_HASKELL__
+isAsciiUpper, isAsciiLower :: Char -> Bool
+isAsciiLower c = c >= 'a' && c <= 'z'
+isAsciiUpper c = c >= 'A' && c <= 'Z'
#endif
+-- | Unicode General Categories (column 2 of the UnicodeData table)
+-- in the order they are listed in the Unicode standard.
+
+data GeneralCategory
+ = UppercaseLetter -- ^ Lu: Letter, Uppercase
+ | LowercaseLetter -- ^ Ll: Letter, Lowercase
+ | TitlecaseLetter -- ^ Lt: Letter, Titlecase
+ | ModifierLetter -- ^ Lm: Letter, Modifier
+ | OtherLetter -- ^ Lo: Letter, Other
+ | NonSpacingMark -- ^ Mn: Mark, Non-Spacing
+ | SpacingCombiningMark -- ^ Mc: Mark, Spacing Combining
+ | EnclosingMark -- ^ Me: Mark, Enclosing
+ | DecimalNumber -- ^ Nd: Number, Decimal
+ | LetterNumber -- ^ Nl: Number, Letter
+ | OtherNumber -- ^ No: Number, Other
+ | ConnectorPunctuation -- ^ Pc: Punctuation, Connector
+ | DashPunctuation -- ^ Pd: Punctuation, Dash
+ | OpenPunctuation -- ^ Ps: Punctuation, Open
+ | ClosePunctuation -- ^ Pe: Punctuation, Close
+ | InitialQuote -- ^ Pi: Punctuation, Initial quote
+ | FinalQuote -- ^ Pf: Punctuation, Final quote
+ | OtherPunctuation -- ^ Po: Punctuation, Other
+ | MathSymbol -- ^ Sm: Symbol, Math
+ | CurrencySymbol -- ^ Sc: Symbol, Currency
+ | ModifierSymbol -- ^ Sk: Symbol, Modifier
+ | OtherSymbol -- ^ So: Symbol, Other
+ | Space -- ^ Zs: Separator, Space
+ | LineSeparator -- ^ Zl: Separator, Line
+ | ParagraphSeparator -- ^ Zp: Separator, Paragraph
+ | Control -- ^ Cc: Other, Control
+ | Format -- ^ Cf: Other, Format
+ | Surrogate -- ^ Cs: Other, Surrogate
+ | PrivateUse -- ^ Co: Other, Private Use
+ | NotAssigned -- ^ Cn: Other, Not Assigned
+ deriving (Eq, Ord, Enum, Read, Show, Bounded, Ix)
+
+-- | The Unicode general category of the character.
+generalCategory :: Char -> GeneralCategory
+#if defined(__GLASGOW_HASKELL__) || defined(__NHC__)
+generalCategory c = toEnum $ fromIntegral $ wgencat $ fromIntegral $ ord c
+#endif
#ifdef __HUGS__
-isLatin1 c = True
+generalCategory c = toEnum (primUniGenCat c)
#endif
+-- derived character classifiers
+
+-- | Selects alphabetic Unicode characters (lower-case, upper-case and
+-- title-case letters, plus letters of caseless scripts and modifiers letters).
+-- This function is equivalent to 'Data.Char.isAlpha'.
+isLetter :: Char -> Bool
+isLetter c = case generalCategory c of
+ UppercaseLetter -> True
+ LowercaseLetter -> True
+ TitlecaseLetter -> True
+ ModifierLetter -> True
+ OtherLetter -> True
+ _ -> False
+
+-- | Selects Unicode mark characters, e.g. accents and the like, which
+-- combine with preceding letters.
+isMark :: Char -> Bool
+isMark c = case generalCategory c of
+ NonSpacingMark -> True
+ SpacingCombiningMark -> True
+ EnclosingMark -> True
+ _ -> False
+
+-- | Selects Unicode numeric characters, including digits from various
+-- scripts, Roman numerals, etc.
+isNumber :: Char -> Bool
+isNumber c = case generalCategory c of
+ DecimalNumber -> True
+ LetterNumber -> True
+ OtherNumber -> True
+ _ -> False
+
+-- | Selects Unicode punctuation characters, including various kinds
+-- of connectors, brackets and quotes.
+isPunctuation :: Char -> Bool
+isPunctuation c = case generalCategory c of
+ ConnectorPunctuation -> True
+ DashPunctuation -> True
+ OpenPunctuation -> True
+ ClosePunctuation -> True
+ InitialQuote -> True
+ FinalQuote -> True
+ OtherPunctuation -> True
+ _ -> False
+
+-- | Selects Unicode symbol characters, including mathematical and
+-- currency symbols.
+isSymbol :: Char -> Bool
+isSymbol c = case generalCategory c of
+ MathSymbol -> True
+ CurrencySymbol -> True
+ ModifierSymbol -> True
+ OtherSymbol -> True
+ _ -> False
+
+-- | Selects Unicode space and separator characters.
+isSeparator :: Char -> Bool
+isSeparator c = case generalCategory c of
+ Space -> True
+ LineSeparator -> True
+ ParagraphSeparator -> True
+ _ -> False
+
+#ifdef __NHC__
+-- dummy implementation
+toTitle :: Char -> Char
+toTitle = toUpper
+#endif
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