-{-# OPTIONS -fno-implicit-prelude #-}
+{-# LANGUAGE CPP, NoImplicitPrelude, ForeignFunctionInterface #-}
{-# OPTIONS -#include "WCsubst.h" #-}
+{-# OPTIONS_HADDOCK hide #-}
+
-----------------------------------------------------------------------------
-- |
-- Module : GHC.Unicode
--
-----------------------------------------------------------------------------
+-- #hide
module GHC.Unicode (
isAscii, isLatin1, isControl,
isAsciiUpper, isAsciiLower,
) where
import GHC.Base
-import GHC.Real (fromIntegral)
-import GHC.Int
-import GHC.Word
-import GHC.Num (fromInteger)
+import GHC.Real (fromIntegral)
+import Foreign.C.Types (CInt)
#include "HsBaseConfig.h"
-- | Selects the first 128 characters of the Unicode character set,
-- corresponding to the ASCII character set.
isAscii :: Char -> Bool
-isAscii c = c < '\x80'
+isAscii c = c < '\x80'
-- | Selects the first 256 characters of the Unicode character set,
-- corresponding to the ISO 8859-1 (Latin-1) character set.
isLatin1 :: Char -> Bool
isLatin1 c = c <= '\xff'
-isAsciiUpper, isAsciiLower :: Char -> Bool
+-- | Selects ASCII lower-case letters,
+-- i.e. characters satisfying both 'isAscii' and 'isLower'.
+isAsciiLower :: Char -> Bool
isAsciiLower c = c >= 'a' && c <= 'z'
+
+-- | Selects ASCII upper-case letters,
+-- i.e. characters satisfying both 'isAscii' and 'isUpper'.
+isAsciiUpper :: Char -> Bool
isAsciiUpper c = c >= 'A' && c <= 'Z'
-- | Selects control characters, which are the non-printing characters of
-- (letters, numbers, marks, punctuation, symbols and spaces).
isPrint :: Char -> Bool
--- | Selects white-space characters in the Latin-1 range.
--- (In Unicode terms, this includes spaces and some control characters.)
+-- | Returns 'True' for any Unicode space character, and the control
+-- characters @\\t@, @\\n@, @\\r@, @\\f@, @\\v@.
isSpace :: Char -> Bool
-- isSpace includes non-breaking space
-- Done with explicit equalities both for efficiency, and to avoid a tiresome
-- recursion with GHC.List elem
-isSpace c = c == ' ' ||
- c == '\t' ||
- c == '\n' ||
- c == '\r' ||
- c == '\f' ||
- c == '\v' ||
- c == '\xa0' ||
- iswspace (fromIntegral (ord c)) /= 0
-
--- | Selects alphabetic Unicode characters (letters) that are not lower-case.
--- (In Unicode terms, this includes letters in upper and title cases,
--- as well as modifier letters and other letters.)
+isSpace c = c == ' ' ||
+ c == '\t' ||
+ c == '\n' ||
+ c == '\r' ||
+ c == '\f' ||
+ c == '\v' ||
+ c == '\xa0' ||
+ iswspace (fromIntegral (ord c)) /= 0
+
+-- | Selects upper-case or title-case alphabetic Unicode characters (letters).
+-- Title case is used by a small number of letter ligatures like the
+-- single-character form of /Lj/.
isUpper :: Char -> Bool
-- | Selects lower-case alphabetic Unicode characters (letters).
isLower :: Char -> Bool
--- | Selects alphabetic Unicode characters (letters).
+-- | 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.isLetter'.
isAlpha :: Char -> Bool
-- | Selects alphabetic or numeric digit Unicode characters.
-- | Selects ASCII digits, i.e. @\'0\'@..@\'9\'@.
isDigit :: Char -> Bool
-isDigit c = c >= '0' && c <= '9'
+isDigit c = c >= '0' && c <= '9'
-- | Selects ASCII octal digits, i.e. @\'0\'@..@\'7\'@.
isOctDigit :: Char -> Bool
-isOctDigit c = c >= '0' && c <= '7'
+isOctDigit c = c >= '0' && c <= '7'
-- | Selects ASCII hexadecimal digits,
-- i.e. @\'0\'@..@\'9\'@, @\'a\'@..@\'f\'@, @\'A\'@..@\'F\'@.
isHexDigit :: Char -> Bool
-isHexDigit c = isDigit c || c >= 'A' && c <= 'F' ||
+isHexDigit c = isDigit c || c >= 'A' && c <= 'F' ||
c >= 'a' && c <= 'f'
--- | Convert a letter to the corresponding upper-case letter, leaving any
--- other character unchanged. Any Unicode letter which has an upper-case
--- equivalent is transformed.
+-- | Convert a letter to the corresponding upper-case letter, if any.
+-- Any other character is returned unchanged.
toUpper :: Char -> Char
--- | Convert a letter to the corresponding lower-case letter, leaving any
--- other character unchanged. Any Unicode letter which has a lower-case
--- equivalent is transformed.
+-- | Convert a letter to the corresponding lower-case letter, if any.
+-- Any other character is returned unchanged.
toLower :: Char -> Char
--- | Convert a letter to the corresponding title-case letter, leaving any
--- other character unchanged. Any Unicode letter which has a lower-case
--- equivalent is transformed.
+-- | Convert a letter to the corresponding title-case or upper-case
+-- letter, if any. (Title case differs from upper case only for a small
+-- number of ligature letters.)
+-- Any other character is returned unchanged.
toTitle :: Char -> Char
-- -----------------------------------------------------------------------------
-- Regardless of the O/S and Library, use the functions contained in WCsubst.c
-type WInt = HTYPE_WINT_T
-type CInt = HTYPE_INT
-
isAlpha c = iswalpha (fromIntegral (ord c)) /= 0
isAlphaNum c = iswalnum (fromIntegral (ord c)) /= 0
--isSpace c = iswspace (fromIntegral (ord c)) /= 0
toUpper c = chr (fromIntegral (towupper (fromIntegral (ord c))))
toTitle c = chr (fromIntegral (towtitle (fromIntegral (ord c))))
-foreign import ccall unsafe "u_iswdigit"
- iswdigit :: CInt -> CInt
-
foreign import ccall unsafe "u_iswalpha"
iswalpha :: CInt -> CInt
towtitle :: CInt -> CInt
foreign import ccall unsafe "u_gencat"
- wgencat :: CInt -> Int
+ wgencat :: CInt -> CInt
-- -----------------------------------------------------------------------------
-- No libunicode, so fall back to the ASCII-only implementation (never used, indeed)
#else
-isControl c = c < ' ' || c >= '\DEL' && c <= '\x9f'
-isPrint c = not (isControl c)
+isControl c = c < ' ' || c >= '\DEL' && c <= '\x9f'
+isPrint c = not (isControl c)
-- The upper case ISO characters have the multiplication sign dumped
-- randomly in the middle of the range. Go figure.
-isUpper c = c >= 'A' && c <= 'Z' ||
+isUpper c = c >= 'A' && c <= 'Z' ||
c >= '\xC0' && c <= '\xD6' ||
c >= '\xD8' && c <= '\xDE'
-- The lower case ISO characters have the division sign dumped
-- randomly in the middle of the range. Go figure.
-isLower c = c >= 'a' && c <= 'z' ||
+isLower c = c >= 'a' && c <= 'z' ||
c >= '\xDF' && c <= '\xF6' ||
c >= '\xF8' && c <= '\xFF'
-isAlpha c = isLower c || isUpper c
-isAlphaNum c = isAlpha c || isDigit c
+isAlpha c = isLower c || isUpper c
+isAlphaNum c = isAlpha c || isDigit c
-- Case-changing operations
| isAsciiLower c = C# (chr# (ord# c# -# 32#))
| isAscii c = c
-- fall-through to the slower stuff.
- | isLower c && c /= '\xDF' && c /= '\xFF'
+ | isLower c && c /= '\xDF' && c /= '\xFF'
= unsafeChr (ord c `minusInt` ord 'a' `plusInt` ord 'A')
| otherwise
= c
toLower c@(C# c#)
| isAsciiUpper c = C# (chr# (ord# c# +# 32#))
| isAscii c = c
- | isUpper c = unsafeChr (ord c `minusInt` ord 'A' `plusInt` ord 'a')
- | otherwise = c
+ | isUpper c = unsafeChr (ord c `minusInt` ord 'A' `plusInt` ord 'a')
+ | otherwise = c
#endif
projects / ghc-base.git / blobdiff