26 lines
910 B
Haskell
26 lines
910 B
Haskell
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{-# LANGUAGE LambdaCase #-}
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{-# LANGUAGE OverloadedStrings #-}
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{-# LANGUAGE QuasiQuotes #-}
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module ArglibNetencode where
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import qualified Data.Attoparsec.ByteString as Atto
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import Data.Maybe (fromMaybe)
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import ExecHelpers
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import MyPrelude
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import Netencode
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import qualified System.Environment as Env
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import qualified System.Posix.Env.ByteString as ByteEnv
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arglibNetencode :: CurrentProgramName -> Maybe Text -> IO T
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arglibNetencode progName mEnvvar = do
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let envvar = mEnvvar & fromMaybe "ARGLIB_NETENCODE" & textToBytesUtf8
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ByteEnv.getEnv envvar >>= \case
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Nothing -> dieUserError progName [fmt|could not read args, envvar {envvar} not set|]
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Just bytes ->
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case Atto.parseOnly (Netencode.netencodeParser <* Atto.endOfInput) bytes of
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Left err -> dieEnvironmentProblem progName [fmt|arglib parsing error: {err}|]
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Right t -> do
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ByteEnv.unsetEnv envvar
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pure t
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