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-- | Calculate the width of String and Text, being aware of wide characters.
module Text.WideString (
-- * Text Builders which keep track of length
WideBuilder(..),
wbUnpack,
wbToText,
wbFromText
) where
import Data.Text (Text)
import Data.Text.Lazy qualified as TL
import Data.Text.Lazy.Builder qualified as TB
import Text.DocLayout (realLength)
-- | Helper for constructing Builders while keeping track of text width.
data WideBuilder = WideBuilder
{ wbBuilder :: !TB.Builder
, wbWidth :: !Int
} deriving (Show)
instance Semigroup WideBuilder where
WideBuilder x i <> WideBuilder y j = WideBuilder (x <> y) (i + j)
instance Monoid WideBuilder where
mempty = WideBuilder mempty 0
-- | Convert a WideBuilder to a strict Text.
wbToText :: WideBuilder -> Text
wbToText = TL.toStrict . TB.toLazyText . wbBuilder
-- | Convert a strict Text to a WideBuilder.
wbFromText :: Text -> WideBuilder
wbFromText t = WideBuilder (TB.fromText t) (realLength t)
-- | Convert a WideBuilder to a String.
wbUnpack :: WideBuilder -> String
wbUnpack = TL.unpack . TB.toLazyText . wbBuilder
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