graphql-engine/server/src-lib/Hasura/Prelude.hs
Robert c9481d4599 server: remove align, These(..) from Prelude
This removes the module re-exports of [Data.Align](https://hackage.haskell.org/package/semialign-1.2/docs/Data-Align.html) and [Data.These](https://hackage.haskell.org/package/these-1.1.1.1/docs/Data-These.html) from `Hasura.Prelude`. The reasoning being that they're not used widely and reasonably obscure, and that being explicit about the imports makes for an easier to understand codebase.

(I spent longer than I'd have liked earlier today figuring out where `align` in multitenant came from.
The right one not showing up on the first hoogle page doesn't help. Yes, better tool use could have
avoided that, but still...)

Do feel free to shoot this down, I won't insist on the change.

https://github.com/hasura/graphql-engine-mono/pull/2194

GitOrigin-RevId: 10f887b74538b17623bee6d6451c5aba11573fbd
2021-08-24 17:42:13 +00:00

251 lines
9.0 KiB
Haskell

{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Hasura.Prelude
( module M
, alphabet
, alphaNumerics
, onNothing
, onJust
, onLeft
, whenMaybe
, choice
, afold
, bsToTxt
, lbsToTxt
, txtToBs
, base64Decode
, spanMaybeM
, liftEitherM
, hoistMaybe
, hoistEither
, tshow
-- * Trace debugging
, ltrace
, ltraceM
-- * Efficient coercions
, coerce
, findWithIndex
-- * Map-related utilities
, mapFromL
, mapKeys
, oMapFromL
-- * Measuring and working with moments and durations
, withElapsedTime
, startTimer
-- * Aeson options
, hasuraJSON
-- * Extensions to @Data.Foldable@
, fold'
, module Data.Time.Clock.Units
) where
import Control.Applicative as M (Alternative (..), liftA2)
import Control.Arrow as M (first, second, (&&&), (***), (<<<), (>>>))
import Control.DeepSeq as M (NFData, deepseq, force)
import Control.Lens as M (ix, (%~))
import Control.Monad.Base as M
import Control.Monad.Except as M
import Control.Monad.Identity as M
import Control.Monad.Reader as M
import Control.Monad.State.Strict as M
import Control.Monad.Trans.Maybe as M (MaybeT (..))
import Control.Monad.Writer.Strict as M (MonadWriter (..), WriterT (..), execWriterT,
runWriterT)
import Data.Bool as M (bool)
import Data.Coerce
import Data.Data as M (Data (..))
import Data.Either as M (lefts, partitionEithers, rights)
import Data.Foldable as M (asum, fold, foldMap', foldlM, foldrM, for_,
toList, traverse_)
import Data.Function as M (on, (&))
import Data.Functor as M (($>), (<&>))
import Data.Functor.Const as M (Const)
import Data.HashMap.Strict as M (HashMap)
import Data.HashMap.Strict.InsOrd as M (InsOrdHashMap)
import Data.HashSet as M (HashSet)
import Data.Hashable as M (Hashable)
import Data.List as M (find, findIndex, foldl', group, intercalate,
intersect, lookup, sort, sortBy, sortOn, union,
unionBy, (\\))
import Data.List.NonEmpty as M (NonEmpty (..), nonEmpty)
import Data.Maybe as M (catMaybes, fromMaybe, isJust, isNothing,
listToMaybe, mapMaybe, maybeToList)
import Data.Monoid as M (getAlt)
import Data.Ord as M (comparing)
import Data.Semigroup as M (Semigroup (..))
import Data.Sequence as M (Seq)
import Data.Sequence.NonEmpty as M (NESeq)
import Data.String as M (IsString)
import Data.Text as M (Text)
import Data.Time.Clock.Units
import Data.Traversable as M (for)
import Data.Void as M (Void, absurd)
import Data.Word as M (Word64)
import GHC.Generics as M (Generic)
import Prelude as M hiding (fail, init, lookup)
import Text.Read as M (readEither, readMaybe)
import qualified Data.Aeson as J
import qualified Data.Aeson.Casing as J
import qualified Data.ByteString as B
import qualified Data.ByteString.Base64.Lazy as Base64
import qualified Data.ByteString.Lazy as BL
import qualified Data.HashMap.Strict as Map
import qualified Data.HashMap.Strict.InsOrd as OMap
import qualified Data.Hashable as H
import qualified Data.Text as T
import qualified Data.Text.Encoding as TE
import qualified Data.Text.Encoding.Error as TE
import qualified Data.Text.Lazy as TL
import qualified GHC.Clock as Clock
import Debug.Trace (trace, traceM)
import qualified Text.Pretty.Simple as PS
alphabet :: String
alphabet = ['a'..'z'] ++ ['A'..'Z']
alphaNumerics :: String
alphaNumerics = alphabet ++ "0123456789"
onNothing :: Applicative m => Maybe a -> m a -> m a
onNothing m act = maybe act pure m
onJust :: Applicative m => Maybe a -> (a -> m ()) -> m ()
onJust m action = maybe (pure ()) action m
onLeft :: Applicative m => Either e a -> (e -> m a) -> m a
onLeft e f = either f pure e
whenMaybe :: Applicative m => Bool -> m a -> m (Maybe a)
whenMaybe True = fmap Just
whenMaybe False = const $ pure Nothing
choice :: Alternative f => [f a] -> f a
choice = asum
afold :: (Foldable t, Alternative f) => t a -> f a
afold = getAlt . foldMap pure
bsToTxt :: B.ByteString -> Text
bsToTxt = TE.decodeUtf8With TE.lenientDecode
lbsToTxt :: BL.ByteString -> Text
lbsToTxt = bsToTxt . BL.toStrict
txtToBs :: Text -> B.ByteString
txtToBs = TE.encodeUtf8
base64Decode :: Text -> BL.ByteString
base64Decode =
Base64.decodeLenient . BL.fromStrict . txtToBs
-- Like `liftEither`, but accepts a monadic action
liftEitherM :: MonadError e m => m (Either e a) -> m a
liftEitherM action = action >>= liftEither
-- Like 'span', but monadic and with a function that produces 'Maybe' instead of 'Bool'
spanMaybeM
:: (Foldable f, Monad m)
=> (a -> m (Maybe b)) -> f a -> m ([b], [a])
spanMaybeM f = go . toList
where
go [] = pure ([], [])
go l@(x:xs) = f x >>= \case
Just y -> first (y:) <$> go xs
Nothing -> pure ([], l)
findWithIndex :: (a -> Bool) -> [a] -> Maybe (a, Int)
findWithIndex p l = do
v <- find p l
i <- findIndex p l
pure (v, i)
-- TODO (from main): Move to Data.HashMap.Strict.Extended; rename to fromListWith?
mapFromL :: (Eq k, Hashable k) => (a -> k) -> [a] -> Map.HashMap k a
mapFromL f = Map.fromList . map (\v -> (f v, v))
-- | re-key a map. In the case that @f@ is not injective you may end up with a
-- smaller map than what you started with.
--
-- This may be a code smell.
mapKeys :: (Eq k2, Hashable k2) => (k1 -> k2) -> Map.HashMap k1 a -> Map.HashMap k2 a
mapKeys f = Map.fromList . map (first f) . Map.toList
oMapFromL :: (Eq k, Hashable k) => (a -> k) -> [a] -> InsOrdHashMap k a
oMapFromL f = OMap.fromList . map (\v -> (f v, v))
-- | Time an IO action, returning the time with microsecond precision. The
-- result of the input action will be evaluated to WHNF.
--
-- The result 'DiffTime' is guarenteed to be >= 0.
withElapsedTime :: MonadIO m => m a -> m (DiffTime, a)
withElapsedTime ma = do
bef <- liftIO Clock.getMonotonicTimeNSec
!a <- ma
aft <- liftIO Clock.getMonotonicTimeNSec
let !dur = nanoseconds $ fromIntegral (aft - bef)
return (dur, a)
-- | Start timing and return an action to return the elapsed time since 'startTimer' was called.
--
-- @
-- timer <- startTimer
-- someStuffToTime
-- elapsed <- timer
-- moreStuff
-- elapsedBoth <- timer
-- @
startTimer :: (MonadIO m, MonadIO n) => m (n DiffTime)
startTimer = do
!bef <- liftIO Clock.getMonotonicTimeNSec
return $ do
aft <- liftIO Clock.getMonotonicTimeNSec
return $ nanoseconds $ fromIntegral (aft - bef)
-- | Upgrade a 'Maybe' to a 'MaybeT'.
--
-- cf. http://hackage.haskell.org/package/errors-2.3.0/docs/src/Control.Error.Util.html#hoistMaybe
hoistMaybe :: Applicative m => Maybe b -> MaybeT m b
hoistMaybe = MaybeT . pure
-- | Upgrade an 'Either' to an 'ExceptT'.
--
-- cf. http://hackage.haskell.org/package/errors-2.3.0/docs/src/Control.Error.Util.html#hoistEither
hoistEither :: Applicative m => Either e a -> ExceptT e m a
hoistEither = ExceptT . pure
tshow :: Show a => a -> Text
tshow = T.pack . show
-- | Customized 'J.Options' which apply "snake case" to Generic or Template
-- Haskell JSON derivations.
--
-- For example, a Haskell field @fooBar@ would be de/serialized from/to JSON as
-- @foo_bar@.
hasuraJSON :: J.Options
hasuraJSON = J.aesonPrefix J.snakeCase
instance (Hashable a) => Hashable (Seq a) where
hashWithSalt i = H.hashWithSalt i . toList
-- | Given a structure with elements whose type is a 'Monoid', combine them via
-- the monoid's @('<>')@ operator.
--
-- This fold is right-associative and strict in the accumulator; it's defined
-- as @foldMap id@, per the documentation in @Data.Foldable@.
fold' :: (Monoid m, Foldable t) => t m -> m
fold' = foldMap' id
-- Fancy trace debugging
-- | Labeled, prettified traceShowId
ltrace :: Show a => String -> a -> a
ltrace lbl x = trace (lbl <> ": " <> TL.unpack (PS.pShow x)) x
{-# warning ltrace "ltrace left in code" #-}
-- | Labeled, prettified traceShowM
ltraceM :: Applicative m => Show a => String -> a -> m ()
ltraceM lbl x = traceM (lbl <> ": " <> TL.unpack (PS.pShow x))
{-# warning ltraceM "ltraceM left in code" #-}