-- This file is part of purebred-icu -- Copyright (C) 2019 Fraser Tweedale -- -- purebred-icu is free software: you can redistribute it and/or modify -- it under the terms of the GNU Affero General Public License as published by -- the Free Software Foundation, either version 3 of the License, or -- (at your option) any later version. -- -- This program is distributed in the hope that it will be useful, -- but WITHOUT ANY WARRANTY; without even the implied warranty of -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -- GNU Affero General Public License for more details. -- -- You should have received a copy of the GNU Affero General Public License -- along with this program. If not, see <http://www.gnu.org/licenses/>. {- | Add support for many more charsets to the purebred MUA. It uses the /text-icu/ library (and /libicu/ under the hood) to convert text. To enable text-icu: @ import Purebred import qualified Purebred.Plugin.ICU main = purebred $ tweak defaultConfig where tweak :: UserConfiguration -> UserConfiguration tweak = 'Purebred.Plugin.ICU.enable' @ -} module Purebred.Plugin.ICU ( icuCharsets , enable ) where import Control.Applicative ((<|>), liftA2) import Control.Exception (catch) import System.IO.Unsafe (unsafePerformIO) import Control.Lens (over) import Data.CaseInsensitive (original) import Data.MIME (CharsetLookup) import Data.Text as T import Data.Text.Encoding as T import Data.Text.Encoding.Error as T import Data.Text.ICU.Convert (open, toUnicode) import Data.Text.ICU.Error (ICUError) import Purebred -- | Install the ICU charsets, preserving and preferring the -- existing lookup function. -- enable :: UserConfiguration -> UserConfiguration enable = over confCharsets (flip (liftA2 (<|>)) icuCharsets) -- | Just the ICU charset lookup function, in case you want to use -- it by itself, or combine it with other lookups differently from -- how 'enable' combines them. -- icuCharsets :: CharsetLookup icuCharsets k = let k' = T.unpack . T.decodeUtf8With T.lenientDecode . original $ k handler = const (pure Nothing) :: ICUError -> IO (Maybe a) conv = unsafePerformIO $ (Just <$> open k' Nothing) `catch` handler in toUnicode <$> conv