Daniel Yokomizo dyokomizo

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

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?

This article has been given a more permanent home on my blog. Also, since it was first written, the development of the Promises/A+ specification has made the original emphasis on Promises/A seem somewhat outdated.

You're Missing the Point of Promises

Promises are a software abstraction that makes working with asynchronous operations much more pleasant. In the most basic definition, your code will move from continuation-passing style:

getTweetsFor("domenic", function (err, results) {
 // the rest of your code goes here.

Emails from Matthew

http://lists.racket-lang.org/users/archive/2005-August/009483.html

http://lists.racket-lang.org/users/archive/2005-November/010350.html

http://lists.racket-lang.org/users/archive/2006-June/013819.html

http://lists.racket-lang.org/users/archive/2006-August/014439.html

GitHub Compare Links

The Basics

Ok, so the basic anatomy of a GitHub compare link is:

https://github.com/USER/REPO/compare/REF1...REF2

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!

	// needs -fnested-functions. Can be done without, but makes the whole thing a lot more cumbersome
	// and less useful.
	#include <stdio.h>

	#define my_data_alts ( void (A)(int) , void (B)(int, int) , void (*C)(char, int) )
	#define make_my_data(n) void n my_data_alts
	typedef void (*my_data) my_data_alts;


	void show(my_data match) {

	#lang racket/base

	(define tasklist (list (list 'root (box 'no-continuation))))
	(define currtask tasklist)

	(define call/cc call-with-current-continuation)

	(define fork
	(lambda (name)
	(call/cc

	module Types where

	open import Level
	open import Function
	open import Algebra
	open import Data.Empty
	open import Data.Unit
	open import Data.Sum as Sum
	open import Data.Product as Prod
	open import Relation.Binary

	var parser = document.createElement('a');
	parser.href = "http://example.com:3000/pathname/?search=test#hash";

	parser.protocol; // => "http:"
	parser.hostname; // => "example.com"
	parser.port; // => "3000"
	parser.pathname; // => "/pathname/"
	parser.search; // => "?search=test"
	parser.hash; // => "#hash"
	parser.host; // => "example.com:3000"