Exploring Arrows for sequencing effects

ChrisPenner · November 20, 2025, 11:18pm

Building on my previous post, I explore how we can use Arrows to represent your effects, and how it can provide pretty substantial benefits in your ability to analyze effectful programs at runtime.

ibizaman · November 24, 2025, 3:57pm

As an Arrow newbie, the first post explained well the expressiveness problem with Monads and the second was enlightening on Arrow. Thank you for writing those!

brandonchinn178 · November 25, 2025, 4:44am

Thanks for this! I also read this back in October and renewed my interest in arrows, which I’d been interested in learning for quite a while. I finally found a use-case / excuse to try it out, and think it’s pretty nice!

github.com/brandonchinn178/hooky

src%2FHooky%2FConfig.hs

main

{-# LANGUAGE Arrows #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE NoFieldSelectors #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}

module Hooky.Config (
  Config (..),
  parseConfig,
  Glob (..),
  HookConfig (..),
  PassFilesMode (..),
  LintRule (..),
  LintRuleRule (..),
  lintRuleName,
) where

import Control.Arrow (returnA)
import Data.Bifunctor qualified as Bifunctor

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