My Clojure IDE (codename: Leviathan) is almost ready for every-day use. One of the last remaining big problems is that it doesn’t correctly handle non-ASCII characters yet.
An easy way to solve this would be to use NSStrings, which automatically handle most of the UTF-8 functionality I would ever need. (Mike Ash wrote a great summary of how UTF-8 works.) But my data structures are represented as C structs, which can’t store ObjC objects when ARC is enabled.
So this morning I gave it a try. Shortly after the sun rose, I spent about an hour converting these structs to classes. Unfortunately the version with structs is about 10x faster (sometimes almost 20x) than the version with classes. It was unacceptably slow, so I had to scrap it and go back to C structs.
Right now my tokens are pointing to
bstring instances, from bstrlib. It’s pretty fast, but this library doesn’t handle UTF-8 either.
So I need a way to modify, inspect, and store UTF-8 strings without NSString.
But I rarely need to manipulate token-strings directly. The vast majority of the time, I’m just asking for their entire length when trying to find out where the cursor is in my parse-tree. This should be O(1) since it happens very often for things like auto-indentation. That probably means storing the length and the char* together, like bstring does.
Modifying strings can’t quite be O(1), because it has to know character-indices, not byte-indices, and because of UTF-8’s nature, that requires either walking the string or caching information for every character. But that’s okay, because I only ever need to manipulate a token’s UTF-8 string directly when a user presses a key, which in CPU time is once every few centuries.
So for now, I can probably get away with finding a UTF-8 library that gives me functions to inspect and modify C strings represented by
char*. Then I’ll just store the char* and its length together. There’s a few options on this stackoverflow page that look promising.
Even though it’s a little annoying that I can’t use NSString, it’s probably for the better, since the overhead for method calls are overkill for a little string manipulation. It seems like using C functions and a custom struct will be a good long-term solution.
Update: Yeah, I totally forgot I can just use CFString. Oops.
My name is Steven Degutis, and I've been writing software professionally for a decade. During that time, I've written many apps and websites, quite a few technical articles, and kept up-to-date with the rapidly evolving software industry.
If you have software needs for web, mobile, or desktop, and are looking for a seasoned software professional, please reach out to me at email@example.com to set up a phone call.
- Self-employed – present
- Clean Coders – 5 years
- 8th Light – 2 years
- Big Nerd Ranch – 1 year
- Self-employed - 1 year
- Web: full-stack
- iOS (UIKit)
- macOS (Cocoa)
- REST APIs
- AWS / EC2 / ELB
- HTML5 / CSS
Over the past decade, I've written a total of 172 technical articles on various programming languages, frameworks, best practices, and my own projects, as I kept up-to-date and active in the software industry.
Subscribe via RSS / Atom.
- 2017 — "Clean code" isn't actually clean
- 2017 — Passion in your field is overrated
- 2017 — What I learned in 5 days of writing an experimental website
- 2014 — Age of the Polyglot
- 2013 — How to Program
- 2013 — Ignore the Naysayers
- 2013 — Writing Clearly
- 2012 — Reinvent the wheel
- 2010 — Good usability
- 2009 — Twitter is the wrong tool
- 2009 — We're all pretty bad at driving
- 2008 — Why I Code
|August||NDD: Narrative Driven Development|
|August||The truth about TDD|
|August||Macroframeworks vs Microframeworks|
|March||Notes on Haskell Extensions|
|February||Second thoughts on front-end tools|
|February||First thoughts on front-end tools|
|February||Some thoughts on GUIs|
|February||First thoughts on OCaml|
|February||First thoughts on Haskell|
|August||Age of the Polyglot|
|August||The history of Mjolnir|
|August||Quitting the GUI wars|
|June||Lua: my new favorite extension language|
|January||My programming life-goals|
|January||Lingua Latina, Pars I|
|January||Allocating an AST on the stack|
|April||Ruby Accessors Considered Pernicious|
|March||Reinvent the wheel|
Here are some of the projects I'm most proud of. They were created using a variety of technologies, running on several different platforms and OSes. They're all finished products, and many of them are open source.
I made Docks in 2009 for users who wanted to swap out icons in their Dock with a single click. Its unique functionality and design aesthetic attracted the attention of Apple, Engadget, MacWorld, and led to an acquisition of my start-up by Big Nerd Ranch.
This toy was made in a weekend to entertain my 1 year old daughter. It lets you create bubbles with your fingers, which then simulate physics by bumping into each other and falling.
When I couldn't find an app in the App Store that let me make very simple lists extremely quickly, I made one myself. I use it almost every day to organize and track my activities.
I created this app to increase my productivity by letting me move windows around in macOS using keyboard shortcuts. It grew into a community-driven highly extensible app, using Lua for its plugin system.
Implementing this elite social network gave me experience integrating both Apple Pay and credit card payments (via Stripe.com) seamlessly into web apps, for a frictionless and pain-free payment experience.
This isn't just any chatroom. In this web app, you can see what everyone is typing while they type it. I made this in order to scratch my itch for making real-time apps and games, and learned how to use WebSockets in the process.
This was written in 2009, before the time of Slack, when IRC was the main way for programmers to get short-term assistance from each other. Its purpose was to be a beautiful app with an emphasis on simplicity and usability over technical power.
This is an app I actually use every single day. It lets you move windows with global keyboard shortcuts. Since it uses Vim-like key bindings, it should feel pretty natural to any programmer. There's no configuration needed; it Just Works™.
As an evolution of Phoenix, Hydra was my first attempt at embedding a full Lua virtual machine into an Objective-C app, to make a lightweight and efficient window manager that focused on speed, low memory usage, low CPU usage, and overall being gentle on laptop batteries.
These may be tiny, but they're interesting technical feats.
|Lua4Swift||Swift framework for embedding Lua with a native Swift API.|
|choose||Command line fuzzy-matching tool for macOS that uses a GUI|
|music||Command line music daemon for macOS that only speaks JSON|
|hecto||Command line text editor with an embedded Lua plugin system|
|ZephSharp||Window manager for Windows using Clojure for scripting|
|management||Minimalist EC2 configuration & deployment tool in Ruby.|
|go.assert||Assertion helper package for writing tests in Go.|
|go.shattr||Go library for printing shell-attributed strings to stdout.|
|OCDSpec2||Objective-C based testing framework with Xcode integration.|