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hanshoglund / Moore.hs
Created October 5, 2017 16:07
data Moore a b = forall r . Moore (r -> b) (r -> a -> r) r
data Moore2 a b = Moore2 b (a -> Moore2 a b)
l :: Moore2 a b -> Moore a b
l machine = L (\(Moore2 state _) -> state) (\(Moore2 _ step) input -> step input) machine
r :: Moore a n -> Moore2 a b
r (Moore view step state) = Moore2 (view state) (\input -> r $ Moore view step $ step state input)
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hanshoglund / ex.hs
Created October 2, 2017 10:56
ex.hs
-- "Real world examples"
-- Ban "data"
data Foo = Foo Int a
deriving (Eq, Ord, Show, Typeable, Functor, Foldable, Traversable)
-- I can't dervive everything!
-- Solution I:
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hanshoglund / gist:c1a392940984ff497f99cf178b53fa5d
Last active September 16, 2017 19:59
Generate arbitrary modifier (using Arb/CoArb), e.g. a
(Set HaskellFilePath -> Vec (NModsPerRound :: Nat) (HaskellFilePathToModify,Modification))
newtype Modification = (UniqueNameForStats, DescrText, Qualifier, HaskellText -> HaskellText)
type Qualifier -- info such as: Is this an internal module
instance Arbitrary
-- Some clever thing here
-- E.g.
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hanshoglund / EvalQuote.md
Last active August 30, 2017 11:51
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hanshoglund / Effects2.md
Created August 28, 2017 10:46

Handlers

-- Problem: Fill in _ to 'handle' the B effect
-- Try using a separate algebra + freer monad
-- See if one technique subsumes the other

foo :: Write_ A m => m a
foo = _ bar
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hanshoglund / quickrefact.md
Last active March 2, 2018 09:40

QuickRefact

QuickRefact is a heuristic refactoring tool inspired by QuickCheck

While QC generates random test cases to prove that your code has errors, QR generates random modifications to your source code and tries to prove that they don't break the code, using your standard compiler and test suite as the verifier. The changes are generated based on a Haskell DSL a la QuickCheck. Each random edit is a random change that will either improve the code without affecting its meaning (in which case it is merged), or break the build (in which case it is rejected).

Basic idea how QR works:

  • Start with some Git commit
  • Apply some randomly generated changes to the code, then run build/tests
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hanshoglund / Effects.md
Last active May 12, 2018 17:22
Better effect systems
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hanshoglund / tcHomom.hs
Last active July 1, 2017 00:29
-- stack resolver: lts-8.21
-- https://ghc.haskell.org/trac/ghc/ticket/3205
{-# LANGUAGE RankNTypes, MultiParamTypeClasses, FlexibleInstances, LambdaCase, ViewPatterns, FlexibleContexts #-}
import Control.Monad
import Data.Semigroup hiding (Product)
import Data.Monoid hiding (Product, (<>))
import Data.Functor.Identity
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hanshoglund / junestEx.sh
Created June 21, 2017 12:40
# On host machine (e.g. strats1)
cd $HOME
mkdir $FAKEUSER
# The entire env goes in this dir
# Junest env $HOME <-> real $HOME/$FAKEUER
# Junest env / <-> real $HOME/$FAKEUSER/.junest
cd $HOME/$FAKEUSER
# Clone strats, junest and hans-conf repos to $HOME/$FAKEUSER
# Stable example:
# https://github.com/fsquillace/junest, 9cd13c88f6ea7bce144962d97f4f850e5fd5ea07
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hanshoglund / gist:f6ff01cb3a668f774a79454c24cde544
Created June 18, 2017 18:37
https://www.youtube.com/watch?v=XA2WjJbmmoM
https://github.com/neovimhaskell
!! https://www.reddit.com/r/haskell/comments/3wiwhs/anyone_using_neovim/
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