--
-----------------------------------------------------------------------------
+-- #hide
module GHC.Unicode (
isAscii, isLatin1, isControl,
isAsciiUpper, isAsciiLower,
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
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.)
+-- | 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.
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
-- -----------------------------------------------------------------------------