jamii

Specification

Out Of The Tarpit

BOOM Analytics: Exploring Data-Centric, Declarative Programming for the Cloud

Dedalus: Datalog in Time and Space

Logic and Lattices for Distributed Programming

robotlolita

Nested asynchronous objects are a problem with Promises/A+, since you can't nest promises.

Compare Data.Task:

function AsyncMap() {
  this.data = {}
}
// :: String, a -> Task<b, Unit>
AsyncMap.prototype.set = function(key, value) {

lexi-lambda

Racket #langs and the REPL

The Racket platform provides a robust set of tools for developing languages, mostly centered around the macro system and the #lang protocol, which allows providing arbitrary readers to convert text input to syntax objects representing Racket modules. The REPL is a bit more complicated, however, because it has different rules—each expression needs to be dynamically read, assigned lexical context, expanded, compiled, evaluated, and printed, all in real time. (In that sense, perhaps the phrase “REPL” oversimplifies what Racket is doing, but that’s a separate conversation.)

So how does Racket accommodate this in the face of completely arbitrary user-defined languages, some of which may not even support interactive evaluation in a traditional sense? Racket mostly solves this problem by having a related but distinct set of protocols for managing runtime interactions that operates alongside #lang.

Modules and the top level

Racket’s evaluation model divides pretty much ev

brianloveswords

gif-from-tweet

There are so many great GIFs out there and I want to have copies of them. Twitter makes that harder than it should be by converting them to MP4 and not providing access to the source material. To make it easier, I made a bash pipeline that takes a tweet URL and a filename, extracts the MP4 from that tweet and uses ffmpeg to convert back to GIF.

Dependencies

• ffmpeg
  • macOS: brew install ffmpeg
  • Ubuntu/Debian: apt install ffmpeg