chris-martin

find . -not -path '*/\.*' | entr -c -d bash -c 'stack test --fast --haddock && pkill -INT foo 2>&1 | fold -w $(tput cols) -s | head -n $(tput lines)'

bash -c 'X=$(stack exec -- which foo); while true; do $X; done'

chris-martin

{- | Error-accumulating traversals.
-}

{-# LANGUAGE DeriveFunctor, FunctionalDependencies #-}

module Accumulate
    ( Acc(..), accAp, accLiftA2, accTraverse, accSequence, accFold
    ) where

import Control.Applicative

chris-martin

{-# LANGUAGE DeriveGeneric #-}

import GHC.Generics
import Control.Category (Category)
import qualified Control.Category as Cat

-----------------------------------------------------------------------
--  Endofunctions
-----------------------------------------------------------------------

chris-martin

instance Bounded Float where
    minBound = -1/0
    maxBound = 1/0

minimum' :: [Float] -> Float
minimum' = coerce . foldMap Min

maximum' :: [Float] -> Float
maximum' = coerce . foldMap Max

chris-martin

trait Question[R] {

  def ask(ref: ActorRef)(implicit timeout: Timeout, ct: ClassTag[R]):
  Future[R] =
    new AskableActorRef(ref).ask(this).mapTo[R]

  def reply(r: R)(implicit context: ActorContext): Unit =
    context.sender ! r

  def replyWithFuture(f: Future[R])

chris-martin

newtype ConjList a = ConjList [a] deriving Show

instance Monoid a => Monoid (ConjList a) where
    mempty = ConjList $ repeat mempty
    mappend (ConjList x) (ConjList y) = ConjList $ zipWith mappend x y

λ> mappend (ConjList ["ab", "cd"]) (ConjList ["xc", "xy", "xp"])
ConjList ["abxc","cdxy"]
it :: (Monoid a, Data.String.IsString a) => ConjList a

chris-martin

chris@renzo ~> cat ~/.stack/config.yaml 
# This file contains default non-project-specific settings for 'stack', used
# in all projects.  For more information about stack's configuration, see
# http://docs.haskellstack.org/en/stable/yaml_configuration.html
#
nix:
  enable: true
  pure: false
  shell-file: /home/chris/.stack/shell.nix

chris-martin

Standardized Ladder of Functional Programming

The LambdaConf Ladder of Functional Programming (LOFP) is a standardized progression of different concepts and skills that developers must master on their journey to becoming expert-level functional programmers. LOFP can be used to rank workshops, talks, presentations, books, and courseware, so that aspiring functional programmers have a better understanding of what material is appropriate for them given their current experience.

Fire Keramik

Concepts

• Immutable Data
• Second-order Functions

chris-martin

Dear Googler:

‘toJSON’ is not a (visible) method of class ‘FromJSON’

It should be parseJSON.

chris-martin

#!/usr/bin/env stack
-- stack --resolver lts-7.8 --install-ghc runghc --package protolude

{-# LANGUAGE NoImplicitPrelude #-}

import Protolude

merge :: (Eq a, Semigroup a) => [a] -> [a]
merge (x:y:more) | x == y = (x <> y) : more
merge (x:xs) = x : merge xs