VictorTaelin

Implementing complex numbers and FFT with just datatypes (no floats)

In this article, I'll explain why implementing numbers with just algebraic datatypes is desirable. I'll then talk about common implementations of FFT (Fast Fourier Transform) and why they hide inherent inefficiencies. I'll then show how to implement integers and complex numbers with just algebraic datatypes, in a way that is extremely simple and elegant. I'll conclude by deriving a pure functional implementation of complex FFT with just datatypes, no floats.

viercc

{-# LANGUAGE DeriveFunctor #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE FlexibleContexts #-}
module Logistic where

import Data.Kind ( Type )
import Data.Functor.Const
import Data.Functor.Contravariant

palmerj

Buttons

• RSB == Right Stick Button
• LSB == Left Stick Button
• RB == Right Bumper
• RT == Right Trigger
• LB == Left Bumper
• LT == Left Trigger
• Y == Y Button (Top)
• A == A Button (Bottom)

treeowl

{-# LANGUAGE DataKinds, TypeFamilies, TypeOperators, GADTs,
      ScopedTypeVariables, TypeOperators #-}

-- | Type-level natural numbers and singletons, with proofs of
-- a few basic properties.

module BasicNat (
    -- | Type-level natural numbers
    Nat (..)
  , type (+)

canton7

Git Bisect and Feature Branches

There are people out there who claim that merge-based workflows (that is, workflows which contain non-fast-forward merges) are bad. They claim that git bisect gets confused by merge-based workflows, and instead advocate rebase-based workflows without explicit feature branches.

They're wrong.

Furthermore, the "advantages" of their workflows are in fact disadvantages. Let me show you.

simonmichael

# unregister broken GHC packages. Run this a few times to resolve dependency rot in installed packages.                                                                                                                                     
# ghc-pkg-clean -f cabal/dev/packages*.conf also works.                                                                                                                                                                                     
function ghc-pkg-clean() {
    for p in `ghc-pkg check $* 2>&1  | grep problems | awk '{print $6}' | sed -e 's/:$//'`
    do
        echo unregistering $p; ghc-pkg $* unregister $p
    done
}

# remove all installed GHC/cabal packages, leaving ~/.cabal binaries and docs in place.                                                                                                                                                     

chrisjacob

Intro

Description: Setup GitHub Pages "gh-pages" branch and "master" branch as subfolders of a parent project folder ("grandmaster").

Author: Chris Jacob @_chrisjacob

Tutorial (Gist): https://gist.github.com/833223

The Result