Papierkorb / amd64.cpp

Last active April 14, 2018 14:19

The humble beginnings of an AMD64 JIT (Without any libraries)

	/* Compile: $ g++ -std=c++11 -o amd64 amd64.cpp */

	#include <cstdio>
	#include <cstdlib>
	#include <cstdint>
	#include <cstring>
	#include <sys/mman.h>

	// Helper enums so we don't have to poke in bytes directly.
	// You can find the documentation of all of these in the free AMD64 specification:

Papierkorb / bmp.rb

Created January 25, 2018 20:11

Quick and simple BMP writer for Ruby

	# This code is meant for debugging purposes. Its performance is probably bad,
	# it's just meant to work for some hacky scripts you throw out tomorrow :)
	# Create an instance of `Bitmap`, passing the file (IO or string), the width and height.
	# Then push one (or more) 32bit pixels in ARGB format using `Bitmap#<<`.
	# Pixel format is thus: 0xAARRGGBB (Alpha is highest byte, blue lowest).
	# (Alpha is ignored by most programs however)

	class Bitmap
	MAGIC = "BM"

Papierkorb / block_var_crash.cr

Last active January 19, 2018 23:35

	class Boleite::InputReceiver
	def process(event : InputEvent)
	execute_all(@actions, event) unless event.claimed?
	execute_all(@persistent_actions, event)
	end

	private def execute_all(actions, event)
	actions.each{\|act\| act.execute(event) if act.interested?(event)}
	end
	end

Papierkorb / arcane_lvar.cr

Created December 16, 2017 17:28

Demo of type inference of local variables through concurrently ran fibers

	waiter = Channel(Nil).new
	var = "Hello"

	spawn do
	waiter.receive
	var = 5
	end

	puts "var is a #{typeof(var)}"
	puts "var right now is a #{var.class}"

Papierkorb / arcane_ivar.cr

Last active December 16, 2017 17:14

Demo on why `case x = @x` is necessary

	class Foo
	@stuff : String \| Int32

	@waiter = Channel(Nil).new

	def initialize(@stuff)
	spawn do
	@waiter.receive # Simulate waiting for some IO
	@stuff = "Oh noes!" # And store the result of it
	end

Papierkorb / llvm_jit.cr

Created October 31, 2017 15:22

LLVM JIT example in Crystal

	require "llvm"

	# Initialize LLVM. There's also `LLVM.init_arm` if that's what you use.
	LLVM.init_x86

	# The context of everything we'll do. Main book-keeping structure.
	ctx = LLVM::Context.new

	# Code can be separated in different modules. A module can't directly interact
	# with another module. If you'd do that, you'd have to link them.

Papierkorb / test.cr

Last active October 1, 2017 10:25 — forked from Groogy/test.cr


	# Papierkorb suggestion
	class Foo
	include CrystalClear

	requires var > 5 # Pushes "var > 5" into SOME_ARRAY
	ensures result.query? # Pushes "result.query?" into SOME_ARRAY
	contract def foo # Expands to the def, processes SOME_ARRAY, and clears it out for the next method
	# Code
	end

Papierkorb / 000_HOWTO.md

Last active May 25, 2024 08:25

Dynamic library in Crystal

Writing a dynamic library in Crystal, and calling it from C

Download all files.
Build the Crystal part:

crystal build --release --cross-compile --prelude ./no_main library.cr
              ^ You can leave this out
                        ^ We want to link ourselves!
 ^ Use our custom prelude!

Papierkorb / mini_prelude.cr

Created January 26, 2017 21:04


	# Requiring stuff from Crystals standard library
	require "macros"
	require "object"
	require "comparable"
	require "exception"
	require "iterable"
	require "iterator"
	require "indexable"
	require "primitives"

Papierkorb / set-file-association.rb

Created January 14, 2017 00:04

Set KDE/XDG file associations in bulk

	#!/usr/bin/env ruby

	# A script to bulk change file associations. Intended for KDE, but might work
	# with other XDG conforming software. Run it without arguments to see how to
	# use it. Created by me out of frustration, so the code just works ;)

	require "inifile" # gem install inifile

	ASSOC_FILE = "#{ENV['HOME']}/.config/mimeapps.list"
	ASSOC_FILE_BAK = "#{ASSOC_FILE}.bak"

Stefan Merettig Papierkorb

Writing a dynamic library in Crystal, and calling it from C