ghcup-hs/lib/GHCup/Utils/MegaParsec.hs

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2020-04-25 10:06:41 +00:00
{-# LANGUAGE CPP #-}
{-# LANGUAGE OverloadedStrings #-}
module GHCup.Utils.MegaParsec where
import GHCup.Types
import Control.Applicative
import Control.Monad
#if !MIN_VERSION_base(4,13,0)
import Control.Monad.Fail ( MonadFail )
#endif
import Data.Functor
import Data.Maybe
import Data.Text ( Text )
import Data.Versions
import Data.Void
import qualified Data.Text as T
import qualified Text.Megaparsec as MP
choice' :: (MonadFail f, MP.MonadParsec e s f) => [f a] -> f a
choice' [] = fail "Empty list"
choice' [x ] = x
choice' (x : xs) = MP.try x <|> choice' xs
parseUntil :: MP.Parsec Void Text a -> MP.Parsec Void Text Text
parseUntil p = do
(MP.try (MP.lookAhead p) $> mempty)
<|> (do
c <- T.singleton <$> MP.anySingle
c2 <- parseUntil p
pure (c `mappend` c2)
)
parseUntil1 :: MP.Parsec Void Text a -> MP.Parsec Void Text Text
parseUntil1 p = do
i1 <- MP.getOffset
t <- parseUntil p
i2 <- MP.getOffset
if i1 == i2 then fail "empty parse" else pure t
-- | Parses e.g.
-- * armv7-unknown-linux-gnueabihf-ghc
-- * armv7-unknown-linux-gnueabihf-ghci
ghcTargetBinP :: Text -> MP.Parsec Void Text (Maybe Text, Text)
ghcTargetBinP t =
(,)
<$> ( MP.try
(Just <$> (parseUntil1 (MP.chunk "-" *> MP.chunk t)) <* MP.chunk "-"
)
<|> (flip const Nothing <$> mempty)
)
<*> (MP.chunk t <* MP.eof)
-- | Extracts target triple and version from e.g.
-- * armv7-unknown-linux-gnueabihf-8.8.3
-- * armv7-unknown-linux-gnueabihf-8.8.3
ghcTargetVerP :: MP.Parsec Void Text GHCTargetVersion
ghcTargetVerP =
(\x y -> GHCTargetVersion x y)
<$> (MP.try (Just <$> (parseUntil1 (MP.chunk "-" *> verP)) <* MP.chunk "-")
<|> (flip const Nothing <$> mempty)
)
<*> (version' <* MP.eof)
where
verP :: MP.Parsec Void Text Text
verP = do
v <- version'
let startsWithDigists =
and
. take 3
. join
. (fmap . fmap)
(\case
(Digits _) -> True
(Str _) -> False
)
$ (_vChunks v)
if startsWithDigists && not (isJust (_vEpoch v))
then pure $ prettyVer v
else fail "Oh"