mattyw’s gists

mattyw / pierre.exs

Last active December 18, 2015 04:19

Walk the line from http://learnyouahaskell.com/a-fistful-of-monads#walk-the-line done in elixir. The first version shows the advantage of the pipe operator. The update shows us testing for preconditions with 'when' and also using patten matching to make the landleft and right functions easier to read.


	# Inspired by:
	# http://learnyouahaskell.com/a-fistful-of-monads#walk-the-line
	# Put simply, pierre is a tight rope walker. birds land on the left
	# or right of his pole. If the difference is > 3 he falls off

	ExUnit.start

	defmodule WalkTheLine do
	use ExUnit.Case

mattyw / adding.go

Created June 3, 2013 09:54

	package main

	import "fmt"

	type BasketItem struct {
	Id string
	Price int
	}

	type Basket struct {

mattyw / multiple_types.go

Last active November 29, 2018 21:35

	package main

	import (
	"encoding/json"
	"fmt"
	)

	var jsonStr = []byte(`
	{
	"things": [

mattyw / under.go

Created December 30, 2012 23:23

under in go

	package main

	import (
	"fmt"
	"math"
	)

	//Setup some types for functions we want to pass around
	type unaryFloat func(float64) float64
	type binaryFloat func(float64, float64) float64

mattyw / fib.go

Created September 3, 2012 08:12

My solution to http://tour.golang.org/#47

	package main

	import "fmt"

	// fibonacci is a function that returns
	// a function that returns an int.

	func fibonacci() func() int {
	a := 0
	b := 1

mattyw / euler_14.clj

Created June 8, 2012 08:55

Project Euler Problem 14 in Clojure

	(defn collatz [n]
	(if (even? n)
	(/ n 2)
	(inc (* 3 n))))

	(defn collatz-seq [start ls]
	(let [next-number (collatz start)]
	(if (= start 1)
	(conj ls 1)
	(collatz-seq next-number (conj ls start)))))

mattyw / pythag.clj

Created January 8, 2012 06:01

Pythagoras' theorem using J's under idiom in Clojure. See (http://mattyjwilliams.blogspot.com/2012/01/under-new-idiom-from-j-language.html)

	(defn under [verb, obverse, func x y]
	(obverse (func (verb x) (verb y))))

	(defn sqrt [x]
	(Math/sqrt x))

	(defn square [x]
	(Math/pow x 2))

	(defn pythagoras [x y]

mattyw / under.clj

Created January 4, 2012 13:54

J's under conjecture in clojure

	;;Will Suffer from rounding errors - but ok for an example
	(defn under [verb, obverse, func x y]
	(obverse (func (verb x) (verb y))))

	(defn log [x]
	(Math/log x))

	(defn exp [x]
	(Math/exp x))

mattyw / gol.hs

Created December 3, 2011 15:40 — forked from nschmoller/gol.hs

Game of life in Haskell (in 45 minutes)

	zeroes 0 = []
	zeroes n = [0] ++ (zeroes (n-1))

	foo x y z= zipWith (+) (zipWith (+) x y) z

	grid_neighbours l =
	let top = map inc_neighbours ( [(zeroes (length (head l)))] ++ (take (length l) l) )
	bottom = map inc_neighbours ((drop 1 l) ++ [(zeroes (length (head l)))])
	current = map neighbours l
	in zipWith3 foo top bottom current

mattyw / mattyw-4clojure-solution23.clj

Created November 10, 2011 23:04 — forked from anonymous/mattyw-4clojure-solution23.clj

	;; mattyw's solution to Reverse a Sequence
	;; https://4clojure.com/problem/23

	(defn reverse-func [seq]
	(reduce (fn [a b] (cons b a)) '() seq))

	(println (= (reverse-func [1 2 3 4 5]) [5 4 3 2 1]))

Matt Williams mattyw