Converting a code base from camlp4 to ppx
As with many projects in the OCaml world, at Jane Street we have been working on migrating from camlp4 to ppx. After having developed equivalent...
CPU Registers and OCaml
Even though registers are a low-level CPU concept, having some knowledge about them can help write faster code. Simply put, a CPU register is a...
By: Vladimir Brankov
Reverse web proxy in ~50 lines of BASH
In the spirit of reinventing the wheel for fun, I hacked this together as a quick challenge to myself last week. It’s a little rough...
By: Ralph Douglass
Building a lower-latency GC
We’ve been doing a bunch of work recently on improving the responsiveness of OCaml’s garbage collector. I thought it would be worth discussing these developments...
By: Yaron Minsky
Faster OCaml to C calls
The official OCaml documentation “Interfacing C with OCaml” doesn’t document some interesting performance features.
By: Vladimir Brankov
Why GADTs matter for performance
When GADTs (Generalized Algebraic Data Types) landed in OCaml, I wasn’t particularly happy about it. I assumed that it was the kind of nonsense you...
By: Yaron Minsky
A lighter Core
We recently released a version of our open source libraries with a much anticipated change – Async_kernel, the heart of the Async concurrent programming library,...
By: Yaron Minsky
Centralizing distributed version control, revisited
7 years ago, I wrote a blog post about how we at Jane Street were using our distributed version control system (hg, though the story...
By: Yaron Minsky
Making making better
We spend a lot of time and effort on training new people, and it never stops for long. Right now our winter-intern class is ending;...
By: Yaron Minsky
13 Virtues
Very early on in his life, while on lengthy voyage from London to Philadelphia, Ben Franklin created a system of thirteen virtues to live his...
By: David Powers
Inspecting the Environment of a Running Process
Sometimes its useful to be able see the values of environment variables in running processes. We can use the following test program to see how...
By: Chris Perl
How to choose a teaching language
If you were teaching a programming course, what language would you teach it in?
By: Yaron Minsky
Interviewing At Jane Street
Software Engineering Interviews at Jane Street
By: David Powers
What the interns have wrought: RPC_parallel and Core_profiler
We’re in the midst of intern hiring season, and so we get a lot of questions about what it’s like to be an intern at...
By: Yaron Minsky
What is gained and lost with 63-bit integers?
Almost every programming language uses 64-bit integers on typical modern Intel machines. OCaml uses a special 63-bit representation. How does it affect OCaml?
By: Vladimir Brankov
Clearly Failing
The Parable Of The Perfect Connection
By: David Powers
The ML Workshop looks fantastic
I’m a little biased, by being on the steering committee, but this year’s ML workshop looks really interesting. Here’s a link to the program:
By: Yaron Minsky
Simple top-down development in OCaml
Often when writing a new module, I want to write the interface first and save the implementation for later. This lets me use the module...
By: Carl Eastlund
