svevang

# Here Dir points to the directory containing this bash script
DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

svevang

function query() {
  var 
    // HN is done with very unsemantic classes.
    job_list = Array.prototype.slice.call(document.querySelectorAll('.c5a,.cae,.c00,.c9c,.cdd,.c73,.c88')),
    query_list = Array.prototype.slice.call(arguments),
    shown = 0, total = job_list.length;
    
  // Traverses up the dom stack trying to find a match of a specific class
  function up_to(node, klass) {
    if (node.classList.contains(klass)) {

svevang

Code Maintainability

Code maintainability encapsulates the idea of how easy it is to alter existing features or add new features. Changes to software originate in various places: User requirements tend to change with time, new features are requested and existing features may be need to be modified. In addition to the needs of the user or business, associated platforms and tooling can also change, as anyone who has worked through XCode upgrades can attest.

svevang

FROM debian:stable
MAINTAINER Sam Vevang <sam.vevang@gmail.com>

# Nice things
RUN apt-get update && \
apt-get install -y \
vim \
git \
file \
curl

svevang

Always trust in and believe your software

trust in (your software):

Trust in your individual pathway of software development. But remember that in an ergodic walk of the product space the beginnings can be independent of the ends.

believe your software:

Gerald Jay Sussman said that, instead of understanding the entire ensemble, software developers today do basic science on libraries and platforms to figure out how to cobble an application together. Your software belongs to a larger emperical reality. Believe it can be understood.

svevang

== Mantra

Always trust in and believe your software.

svevang

Rust is the new 'Glue Code'

The rust programming language is increasingly popular, valued for it's zero cost memory management and concurrency guarantees. Rust is safe. And it's safe while providing a low level abstraction and compatibility with the C ABI.

Of course, it's not an easy language to write in, relative to (let's say) Ruby. The type system and borrowing in Rust are amazing, but it takes longer to write Rust code because what you are expressing encompasses a complex set of constructs (think borrowing). That's OK because

svevang

Elixir

Binary parsing in elixir is based on pattern matching.

<< "this is a binary literal in elixir" >>

So parsing binaries looks like:

iex(4)> << sign::size(1), exp::size(11), mantissa::size(52) >> = << 3.14159::float >>

svevang

Objective runtime

SICP

Reading up on the objective c runtime, the runtime uses something like what was described in SICP: 2.4.3 Data-Directed Programming and Additivity. Properties, ivars, and classes can be created dynamically at runtime, meaning that there is an abstraction built around the class name and the data (ivars, etc) that are associated with that class. At least the size of a object is not fixed at compile time.

There's some really good analysis of the Objc runtime here:

svevang

#Extract Image URLs and WGet Them to a New Server#

This was a fun problem. I needed to move all the images referenced in a CSS file to another server. I didn't want to just grab all the image files as there were a bunch I didn't need. Here is how I went about it. I am sure you could do it in one step but doing it this way gives you a chance to check for errors.

First you may want to use wget http://otherserver/the_css.css to pull the CSS file on to the target server if it is still on the old server as it was in my case.

1. User grep to extract the URLs from the css file into another file. (You may need to adjust the regular expression if you have funny characters in your file names) Note the use of the -o flag that tells grep to only print out that part of the line that matches the expression rather than the entire line.

    grep -o '\/path\/to\/files\/[a-zA-Z0-9/.:_-]*' the_css.css > images.txt