72 lines
2.7 KiB
Haskell
72 lines
2.7 KiB
Haskell
-- | Calculate the width of String and Text, being aware of wide characters.
|
|
|
|
module Text.WideString (
|
|
-- * wide-character-aware layout
|
|
strWidth,
|
|
textWidth,
|
|
charWidth
|
|
) where
|
|
|
|
import Data.Text (Text)
|
|
import qualified Data.Text as T
|
|
|
|
|
|
-- | Calculate the render width of a string, considering
|
|
-- wide characters (counted as double width)
|
|
strWidth :: String -> Int
|
|
strWidth = foldr (\a b -> charWidth a + b) 0
|
|
|
|
-- | Calculate the render width of a string, considering
|
|
-- wide characters (counted as double width)
|
|
textWidth :: Text -> Int
|
|
textWidth = T.foldr (\a b -> charWidth a + b) 0
|
|
|
|
-- from Pandoc (copyright John MacFarlane, GPL)
|
|
-- see also http://unicode.org/reports/tr11/#Description
|
|
|
|
-- | Get the designated render width of a character: 0 for a combining
|
|
-- character, 1 for a regular character, 2 for a wide character.
|
|
-- (Wide characters are rendered as exactly double width in apps and
|
|
-- fonts that support it.) (From Pandoc.)
|
|
charWidth :: Char -> Int
|
|
charWidth c
|
|
| c < '\x0300' = 1
|
|
| c >= '\x0300' && c <= '\x036F' = 0 -- combining
|
|
| c >= '\x0370' && c <= '\x10FC' = 1
|
|
| c >= '\x1100' && c <= '\x115F' = 2
|
|
| c >= '\x1160' && c <= '\x11A2' = 1
|
|
| c >= '\x11A3' && c <= '\x11A7' = 2
|
|
| c >= '\x11A8' && c <= '\x11F9' = 1
|
|
| c >= '\x11FA' && c <= '\x11FF' = 2
|
|
| c >= '\x1200' && c <= '\x2328' = 1
|
|
| c >= '\x2329' && c <= '\x232A' = 2
|
|
| c >= '\x232B' && c <= '\x2E31' = 1
|
|
| c >= '\x2E80' && c <= '\x303E' = 2
|
|
| c == '\x303F' = 1
|
|
| c >= '\x3041' && c <= '\x3247' = 2
|
|
| c >= '\x3248' && c <= '\x324F' = 1 -- ambiguous
|
|
| c >= '\x3250' && c <= '\x4DBF' = 2
|
|
| c >= '\x4DC0' && c <= '\x4DFF' = 1
|
|
| c >= '\x4E00' && c <= '\xA4C6' = 2
|
|
| c >= '\xA4D0' && c <= '\xA95F' = 1
|
|
| c >= '\xA960' && c <= '\xA97C' = 2
|
|
| c >= '\xA980' && c <= '\xABF9' = 1
|
|
| c >= '\xAC00' && c <= '\xD7FB' = 2
|
|
| c >= '\xD800' && c <= '\xDFFF' = 1
|
|
| c >= '\xE000' && c <= '\xF8FF' = 1 -- ambiguous
|
|
| c >= '\xF900' && c <= '\xFAFF' = 2
|
|
| c >= '\xFB00' && c <= '\xFDFD' = 1
|
|
| c >= '\xFE00' && c <= '\xFE0F' = 1 -- ambiguous
|
|
| c >= '\xFE10' && c <= '\xFE19' = 2
|
|
| c >= '\xFE20' && c <= '\xFE26' = 1
|
|
| c >= '\xFE30' && c <= '\xFE6B' = 2
|
|
| c >= '\xFE70' && c <= '\xFEFF' = 1
|
|
| c >= '\xFF01' && c <= '\xFF60' = 2
|
|
| c >= '\xFF61' && c <= '\x16A38' = 1
|
|
| c >= '\x1B000' && c <= '\x1B001' = 2
|
|
| c >= '\x1D000' && c <= '\x1F1FF' = 1
|
|
| c >= '\x1F200' && c <= '\x1F251' = 2
|
|
| c >= '\x1F300' && c <= '\x1F773' = 1
|
|
| c >= '\x20000' && c <= '\x3FFFD' = 2
|
|
| otherwise = 1
|