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# I found some good resources but they seem to do a bit too much (maybe from a time when there were more bugs).
# So here's a minimal Gist which worked for me as an install on a new M1 Pro.
# Inspired by https://github.com/malob/nixpkgs I highly recommend looking at malob's repo for a more thorough configuration
#
# Let's get started
#
# Let's install nix (at the time of writing this is version 2.5.1
curl -L https://nixos.org/nix/install | sh

# I might not have needed to, but I rebooted

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{-# LANGUAGE GADTs #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE ScopedTypeVariables #-}

-- |
module Arithmetic.Expr where

import Data.Char (chr)
import GHC.Real (RealFrac (truncate))

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{ lib, config, pkgs, ... }:

with lib;

{
  options.v4l2 = mkEnableOption "Enable the confguration to use the reflex as a webcam";
  config = mkIf config.v4l2 {
    # 20.03: v4l2loopback 0.12.5 is required for kernel >= 5.5
    # https://github.com/umlaeute/v4l2loopback/issues/257

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import           Data.Function                  ( fix )
import           Optics

{- Given a binary tree, produce the sums of all
   the paths from the root to each of the leaves.

   NeoVim with HLS (Haskell Language Server)

   $> ghcid -W -a -c 'cabal repl lib:graph-mach-core'

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image: nixpkgs/cachix-flakes:nixos-20.03

build:
  before_script:
    - mkdir -p /etc/nix
    - echo "experimental-features = nix-command flakes ca-references recursive-nix" >> /etc/nix/nix.conf
    - cachix use numtide
    - nix path-info --all > /tmp/store-path-pre-build
  script:
    - nix flake check

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newtype Fn a = Fn {unFn :: a -> a}

instance Semigroup (Fn a) where 
  (<>) (Fn a) (Fn b) = Fn (b . a) 
 
import Control.Monad
import Data.Foldable (fold)
import Data.Monoid (appEndo)
import Hedgehog

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DCPU-16 Specification
Copyright 1985 Mojang
Version 1.7



=== SUMMARY ====================================================================

* 16 bit words
* 0x10000 words of ram

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With scoped effects, handlers must be a part of the program

It is seductive to imagine that effect handlers in an algebraic effect system are not part of the program itself but metalanguage-level folds over the program tree. And in traditional free-like formulations, this is in fact the case. The Eff monad represents the program tree, which has only two cases:

data Eff effs a where
  Pure :: a -> Eff effs a
  Op :: Op effs a -> (a -> Eff effs b) -> Eff effs b

data Op effs a where

smunix

Typing Haskell in Haskell

MARK P. JONES

Pacific Software Research Center

Department of Computer Science and Engineering

Oregon Graduate Institute of Science and Technology