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written, the development of the Promises/A+ specification has made the original emphasis on Promises/A seem somewhat outdated.
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.
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?
In the comments from my last post and on Twitter I noticed a lot of people who had something to say about PHP. The comments were varied but they usally sounded something like this (sorry @ipetepete, I picked yours because it was the shortest).
...the little bits of soul from all of us who've had to work on, and or maintain large PHP applications. – ipetepete
In Pete's defense, he did go on to say that rest of the stack I was using was a "smorgasbord of awesome". Thanks, Pete. I agree!
I would, however, like to take a little time to correct a misperception in the developer community about PHP. I recently got into this same... discussion... with Jeff Atwood, and I seem to be running into it more and more. So here goes. Please bear with me as I cover a little history further on.
Pete, and everybody else, _you're exactly rig
| /* | |
| hidr.js -- hiding and displaying rows or columns | |
| <fieldset class="hidr_buttons"> | |
| <label> <input type="checkbox" value="abc"> </label> | |
| <label> <input type="checkbox" value="def"> </label> | |
| </fieldset> | |
| <table class="hidr"> | |
| <tr class="abc"><td class="def"> Foo </td></tr> |
Let's have some command-line fun with curl, [jq][1], and the [new GitHub Search API][2].
Today we're looking for:
| #!/usr/bin/perl | |
| use strict; | |
| use warnings; | |
| use CGI; | |
| use File::Spec; | |
| use lib $ENV{GL_LIBDIR}; | |
| use Gitolite::Rc; |
| #!env perl | |
| use strict; | |
| use diagnostics; | |
| use Marpa::R2; | |
| use Encode; | |
| use Carp qw/croak/; | |
| use Data::Section -setup; | |
| # Guess why | |
| # --------- |
This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.
The script is here:
#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"
| #!/usr/bin/env python | |
| # | |
| # author: github.com/jbenet | |
| # license: MIT | |
| # | |
| # tikz2svg: convert tikz input into svg | |
| # depends on: | |
| # - pdflatex: comes with your tex dist | |
| # - pdf2svg: brew install pdf2svg |
