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Code Snippet Of the Day (CodeSOD) features interesting and usually incorrect code snippets taken from actual production code in a commercial and/or open source software projects.
Andy C writes:
One of our colleagues dug this code up from an outsourced project. Took a few us to try to find out what it actually does, we're still not completely sure.
"Garbage collected languages can't have memory leaks," is well established as a myth, but we still have plenty of code which refuses to clean up after itself properly.
An anonymous submitter was working with a single-page-app front-end which wraps a stream abstraction around a websocket. Messages arrive on the stream, and callbacks get invoked. When certain parameters change, new callbacks need to be registered to handle the new behavior. The old callbacks need to be unbound- and it's that step this code doesn't do.
Rust is one of the "cool" languages these days. It promises all the low-level power of C with memory safety and "modern" programming conventions like iterables and maps. High performance, expressive language, low-level power seems like a great combination for certain domains.
Now, Jenna Winchester needed to do some Morton Coding or Z-indexing, which is an algorithm which lets you take multidimensional points and turn them into 1-dimensional points in a way that maintains their spatial relationships- essentially a fast way of traversing a quadtree. It's a fairly simple and fast algorithm, especially if you implement it using bitwise operations. A naive implementation, without optimizations, can do its job with very few CPU cycles, relatively speaking.
"Hey," someone on Russell F's team said. "We should add some keyboard navigation to our web app." That struck everyone as an "easy win", specifically because they were really talking about making "enter" and "escape" do something useful.
They wrote some quick requirements, passed it off, and the developer submitted a surprisingly long pull request. Russell passed a sample of three out of the dozens of methods:
If you've worked with developing software of any real complexity, you've probably come across a library or tool that does code generation. Instead of writing all the boring boiler-plate stuff yourself, you maybe throw a little configuration at the system and let it generate all those classes for you. I'd argue that, in most cases, that sort of thing is a code smell- it's not in and of itself bad, but it hints as missed abstractions. There's probably a general way to represent what you want to represent without generating a big pile of classes. The question is: is the additional abstraction worth it, or should you just generate code to get it done?
Russell was recently browsing the documentation for Amazon Web Services. The Java SDK allows you to send requests to AWS to automate things in their cloud. When you send a request, you need an AmazonWebServiceRequest object. Now, AmazonWebServiceRequest is itself an abstract class, so we need to send a concrete implementation, specific to the operation we want to perform. That means it's going to be one of:
Dec 20