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{ Monthly Archives } March 2013

Coupling in a Cocoa[ Touch] App

This is one of my occasional “problem looking for a solution” posts. It’d be great to discuss this over on App.net or G+ or somewhere. I don’t think, at the outset of writing this post, that the last sentence is going to solve the problems identified in the body. I’ve built applications in a few […]

A two-dimensional dictionary

What? A thing I made has just been open-sourced by my employers at Agant: the AGTTwoDimensionalDictionary works a bit like a normal dictionary, except that the keys are CGPoints meaning we can find all the objects within a given rectangle. Why? A lot of time on developing Discworld: The Ankh-Morpork Map was spent on performance […]

“You could simply do X” costs more

Someone always says it. “Could you just add this?” or “I don’t think it would be too hard to…” or if somebody else “changes these two simple things”, someone might create a completely bug-compatible, scale-compatible implementation of this other, undocumented service…wait, what? Many of us are naturally optimistic people. We believe that the problems that […]

The Liskov Citation Principle

In her keynote speech at QCon London 2013 on The Power of Abstraction, Barbara Liskov referred to several papers contemporary with her work on abstract data types. I’ve collected these references and found links to free copies of the articles where available. Dijkstra 1968 Go To statement considered harmful Wirth 1971 Program development by stepwise […]

When all you have is a NailFactory…

…every problem looks like it can be solved by configuring a different nail. We have an obsession with tools in the software industry. We’ve built tools for building software, tools for testing software, tools for recording how the software is broken, tools for recording when we fixed software. Tools for migrating data from the no-longer-cool […]

A note on notes

I’ve always had a way to take notes, but have never settled into a particular scheme. This post, more for my benefit than for yours, is an attempt to dig through this history and decide what I want to do about it. At the high level, the relevant questions are what I want to do […]

How to version a Mach-O library

Yes, it’s the next instalment of “cross-platform programming for people who don’t use Macs very much”. You want to give your dynamic library a version number, probably of the format major.minor.patchlevel. Regardless of marketing concerns, this helps with dependency management if you choose a version convention such that binary-compatible revisions of the libraries can be […]