kar8nga

One-line Tree in Python

Using Python's built-in defaultdict we can easily define a tree data structure:

def tree(): return defaultdict(tree)

That's it!

Mathematics: What do grad students in math do all day?

by Yasha Berchenko-Kogan

A lot of math grad school is reading books and papers and trying to understand what's going on. The difficulty is that reading math is not like reading a mystery thriller, and it's not even like reading a history book or a New York Times article.

The main issue is that, by the time you get to the frontiers of math, the words to describe the concepts don't really exist yet. Communicating these ideas is a bit like trying to explain a vacuum cleaner to someone who has never seen one, except you're only allowed to use words that are four letters long or shorter.

What can you say?

	(* -- mode: ocaml; -- *)

	module type FUNCTOR = sig
	type 'a t
	val map : ('a -> 'b) -> 'a t -> 'b t
	end

	type 'a monoid = {unit : 'a ; join : 'a -> 'a -> 'a}

	type var = string

	stack = []
	compileStacks = []
	words = {}
	builtins = {}
	lambdaType = type(lambda x: x) #cannot compare against the function type directly for some reason

	def prn(o):
	print(o)

	def clr(l):

	#!/usr/bin/env python

	import sys
	import types
	import operator

	class Runtime:
	def __init__(self, env={}, stack=[]):
	self.env = {
	# Primitive words, not an impressive base but it works

	<?php

	// Define the 'class' class
	$class = Obj()
	->fn('new', function ($class) {
	$newClass = Obj($class->methods)
	->fn('new', function($class) {
	$obj = Obj($class->imethods);
	$args = func_get_args();
	array_shift($args);

	# 30 minutes Lisp in Ruby
	# Hong MinHee <http://dahlia.kr/>
	#
	# This Lisp implementation does not provide a s-expression reader.
	# Instead, it uses Ruby syntax like following code:
	#
	# [:def, :factorial,
	# [:lambda, [:n],
	# [:if, [:"=", :n, 1],
	# 1,