magpie

Yeah, when the language isn't flexible enough to let me get rid of boilerplate using its own primitives, I like doing that too. AST classes are a good example of something where a simple script can pound them out. When I was working on Magpie, I did just that. This script[1] generates this file[2]. [1]: https://github.com/munificent/magpie/blob/master/script/gene... [2]: https://github.com/munificent/magpie/blob/master/src/Syntax/... I got this trick from Jim Hugunin, of Jython and IronPython fame.

Note that this post is from October 2010, and it appears that the magpie repo[0] hasn't been committed to in over two years. In addition, the static type system was ripped out of the language about six months after this blog post was written[1]. This is understandable, given that the approach to typing seemed pretty ad-hoc, really unsafe, and somewhat incoherent. The whole point of a type system is to say something about the runtime behavior of a program before you actually run it. To actually execute fragments of your program as part of the type checking step, then, sortof defeats the purpose. Not only that, but typing can fail while producing side effects in your system, some of which may be harmful (launching the nukes, etc.) There are some systems that do _abstract_ interpretation at this point, but that is a model of an execution, no