HeinrichApfelmus’s gists

HeinrichApfelmus / 01_ExampleMonadic.hs

Last active October 11, 2018 14:05

Chart library examples — monadic vs pure API

	plotSpectrum1 lattice n m = toFile def file $ do
	layout_title .= "Spectrum of '" ++ name ++ "'"
	layout_x_axis . laxis_title .= "momentum k (" ++ show m ++ " points)"
	layout_y_axis . laxis_title .= "energy E"
	setColors $ colorGradient blue (length rows)
	forM_ rows $ \row -> plot (line "band" [row])

	where
	...

HeinrichApfelmus / ipython.log

Created January 20, 2014 14:17

Log of a failed installation of IPython when running `IHaskell notebook`.

	------------------------------------------------------------
	/Users/apfelmus/.ihaskell/ipython/bin/pip run on Sun Jan 19 23:56:41 2014
	Obtaining ipython from git+https://github.com/ipython/ipython.git@9c922f54af799704f4000aeee94ec7c74cada194#egg=ipython-dev

	Cloning https://github.com/ipython/ipython.git (to 9c922f54af799704f4000aeee94ec7c74cada194) to /Users/apfelmus/.ihaskell/ipython/src/ipython

	Found command 'git' at '/opt/local/bin/git'
	Running command /opt/local/bin/git clone -q https://github.com/ipython/ipython.git /Users/apfelmus/.ihaskell/ipython/src/ipython
	Running command /opt/local/bin/git submodule update --init --recursive -q
	Running command /opt/local/bin/git tag -l

HeinrichApfelmus / DynamicEventSwitching.hs

Created October 2, 2013 09:54

Create new behaviors and switch between them.

	{-# LANGUAGE Rank2Types #-}
	{-# LANGUAGE ScopedTypeVariables #-}

	import Data.Traversable (sequenceA)
	import Reactive.Banana
	import Reactive.Banana.Frameworks

	newtype Wrapper = Wrapper (forall t. Moment t (Event t () -> Behavior t Integer))

	main :: IO ()

HeinrichApfelmus / InputElement.hs

Created September 9, 2013 13:41

Implementation of an input element adhering to the three principles laid out in http://apfelmus.nfshost.com/blog/2012/03/29-frp-three-principles-bidirectional-gui.html

	{-# LANGUAGE RecordWildCards #-}

	import Data.Monoid
	import Control.Monad

	import qualified Graphics.UI.Threepenny as UI
	import Graphics.UI.Threepenny


	data Input = Input

HeinrichApfelmus / SnapDebugLogChrome

Last active December 17, 2015 09:59

Web servers fail to serve large files on MacOS X.

	-- debug log for querying http://localhost:100000/video.mp4 with Chrome


	Listening on http://0.0.0.0:10000/
	Can't open log file "log/access.log".
	Exception: log/access.log: openFile: does not exist (No such file or directory)
	Logging to stderr instead. THIS IS BAD, YOU OUGHT TO FIX THIS

	Can't open log file "log/error.log".
	Exception: log/error.log: openFile: does not exist (No such file or directory)

HeinrichApfelmus / RandomAccessParser.hs

Last active March 21, 2020 13:11

Parsing a random-access format into a pure data structure. Parsing will be lazy: parts of the data structure will be parsed on demand.

	import Data.Word
	import qualified Data.ByteString as B
	type ByteString = B.ByteString

	data Tree = Leaf [Word8] \| Branch Tree Tree deriving (Eq,Show)

	parse :: ByteString -> Tree
	parse xs = case view xs of
	Cons 0 xs -> case view xs of
	Cons length xs -> Leaf . B.unpack $ B.take (fromIntegral . toInteger $ length) xs

HeinrichApfelmus / CurrencyConverter.js

Created October 19, 2012 15:09

Program compiled with haste that fails with a JavaScript error

	/* Eval
	Evaluate the given thunk t into head normal form.
	If the "thunk" we get isn't actually a thunk, just return it.
	*/
	function E(t) {
	if(t instanceof Thunk) {
	if(t.f) {
	t.x = t.f();
	t.f = 0;
	}

HeinrichApfelmus / gist:3845711

Created October 6, 2012 18:24

Log for haste-boot (2012-10-06)

	peach:~ apfelmus$ haste-boot
	Downloading base libs from ekblad.cc
	Reading package info from stdin ... done.
	Reading package info from stdin ... done.
	Reading package info from stdin ... done.
	Reading package info from stdin ... done.
	Attempting to clone/update: git://github.com/valderman/fursuit.git
	Cloning into fursuit...
	remote: Counting objects: 134, done.
	remote: Compressing objects: 100% (74/74), done.

HeinrichApfelmus / GameLoop.hs

Created October 2, 2012 16:49

Game loop in reactive-banana

	{------------------------------------------------------------------------------
	reactive-banana

	Implementation of an "industry strength" game loop with fixed time step
	and variable fps.

	See also http://gafferongames.com/game-physics/fix-your-timestep/
	-------------------------------------------------------------------------------}
	{-# LANGUAGE NoMonomorphismRestriction #-}
	module Main where

HeinrichApfelmus / Form.html

Created July 19, 2012 13:42

Problem with 'POST' ajax request and Scotty-0.4.4

	<html>
	<head>
	<title>Test</title>
	<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js" /></script>
	<script type="text/javascript" charset="utf-8">
	// onLoad Handler
	$(function () {
	$('#form').submit( function() {
	$.post('/submit', { x : $('#x').val() }, function (result) {
	$('#x').val(result);

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