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bradparker / Main.hs
Last active April 15, 2021 07:18
Some funny problem from a blog post (https://blog.ploeh.dk/2021/04/12/threading-context-through-a-catamorphism/). Excuse for recursion schemes
{-# LANGUAGE BlockArguments #-}
{-# OPTIONS_GHC -Wall #-}
-- nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/bed08131cd29a85f19716d9351940bdc34834492.tar.gz -p 'haskellPackages.ghcWithPackages (p: [p.recursion-schemes])'
module Main where
import Control.Monad.Reader (Reader, asks, local, runReader)
import Data.Foldable (traverse_)
import Data.Functor.Base (TreeF (NodeF))
@bradparker
bradparker / Filtering.hs
Created March 25, 2021 04:06
filtering ::
Applicative f =>
(a -> f Bool)
-> List a
-> f (List a)
filtering p =
flip foldRight (pure Nil) $ \a fas ->
(\b as -> bool as (a :. as) b) <$> p a <*> fas
@bradparker
bradparker / Main.hs
Created March 2, 2021 23:45
Applicative record building from maps
module Main where
import Data.Foldable (traverse_)
import Data.Functor.Compose (Compose (Compose, getCompose))
import Data.Map (Map)
import qualified Data.Map as Map
data Person = Person
{ id :: Int,
name :: String,
@bradparker
bradparker / Primes.hs
Last active December 16, 2020 22:31
Prime sieve
{-# OPTIONS_GHC -Wall #-}
module Main where
import Control.Monad ((<=<))
import Data.Maybe (listToMaybe)
import Numeric.Natural (Natural)
import System.Environment (getArgs)
import Text.Read (readMaybe)
@bradparker
bradparker / .gitignore
Last active December 14, 2020 03:26
Advent of Code 2020
inputs
@bradparker
bradparker / Life.hs
Last active August 9, 2020 10:10
Life
{-# OPTIONS_GHC -Wall #-}
module Life where
import Data.Foldable (for_)
import Control.Comonad.Store (Comonad (..), Store, peek, peeks, store)
import Data.Array ((!), Array, array, bounds)
import Data.Bool (bool)
import Data.List (transpose)
@bradparker
bradparker / Main.hs
Last active February 10, 2021 05:48
I should put this somewhere
module Main where
import Control.Applicative ((<|>))
import Data.Time (TimeZone, ZonedTime, utc, utcToZonedTime, zonedTimeToUTC)
import Data.Time.Format.ISO8601 (iso8601ParseM)
import System.Environment (getArgs)
inTimeZone :: TimeZone -> ZonedTime -> ZonedTime
inTimeZone timezone = utcToZonedTime timezone . zonedTimeToUTC
@bradparker
bradparker / IntervalSets.hs
Last active June 28, 2020 00:16
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# OPTIONS_GHC -Wall #-}
module IntervalSets where
import Control.Arrow ((&&&))
import Control.Monad (filterM)
import Control.Monad.State (evalState, get, modify)
import Control.Monad.Trans.State (StateT (StateT), evalStateT)
@bradparker
bradparker / styled.rb
Last active June 7, 2020 01:21
Sketch of ViewComponent::Styled API
module ViewComponent
module Styled
def self.included(base)
base.extend ClassMethods
end
module ClassMethods
def styled(static = [], &block)
@static_styles = static
@dynamic_styles = block
@bradparker
bradparker / index.html
Last active March 31, 2020 11:47
WebCrypto based SRP
<!DOCTYPE html>
<html>
<head>
<title>SRP</title>
<meta charset="utf8" />
</head>
<body>
<script type="module">
import { modPow } from "https://unpkg.com/[email protected]/src/main.js";