Prelude.hs

{-# LANGUAGE PackageImports #-}

-- | Shōmei shared prelude. Import this module in every Shōmei module instead of
-- importing 'Prelude' directly. Every import here uses PackageImports to pin the
-- originating package and avoid ambiguity when multiple packages re-export the same
-- name.
--
-- Usage:
--
-- > import Shomei.Prelude
--
-- Do NOT add @import "base" Prelude@ after this; GHC2024 hides the default Prelude
-- when you write a custom one.
module Shomei.Prelude
  ( module X,
    module Control.Lens,
    eventAesonOptions,
  )
where

import "aeson" Data.Aeson as X
  ( FromJSON,
    Options (..),
    SumEncoding (..),
    ToJSON,
    camelTo2,
    defaultOptions,
    fromJSON,
    genericParseJSON,
    genericToEncoding,
    genericToJSON,
    parseJSON,
    toEncoding,
    toJSON,
  )
import "base" Control.Applicative as X ((<|>))
import "base" Control.Monad as X
  ( forM,
    forM_,
    guard,
    unless,
    void,
    when,
  )
import "base" Control.Monad.IO.Class as X (MonadIO, liftIO)
import "base" Data.List.NonEmpty as X (NonEmpty (..))
import "base" Data.Maybe as X
  ( fromMaybe,
    isJust,
    isNothing,
    mapMaybe,
  )
import "base" Data.Proxy as X (Proxy (..))
import "base" GHC.Generics as X (Generic)
import "lens" Control.Lens
import "text" Data.Text as X (Text)
import "time" Data.Time as X (UTCTime, getCurrentTime)

-- | Aeson 'Options' for event types: tagged objects with snake_case constructor
-- names and always-tagged single constructors.
--
-- Example: @data MyEvent = UserCreated { ... }@ serialises as
-- @{ "type": "user_created", "data": { ... } }@.
eventAesonOptions :: Options
eventAesonOptions =
  defaultOptions
    { sumEncoding = TaggedObject "type" "data",
      constructorTagModifier = camelTo2 '_',
      tagSingleConstructors = True
    }