From: Clifford Heath Date: 2012-06-19T09:45:25+09:00 Subject: [ruby-core:45706] Comments requested on implementation of set_parse_func Folk, I've implemented Twister, a new mutation testing tool to replace Heckle. It relies on a new hook into the Ruby parser, in order to modify what the parser thinks it has seen. Although I have written C extensions before, there are some aspects of the Ruby core which I'm unfamiliar with and as a result don't know the right way to handle. I'd like your comments, suggestions and improvements please. https://github.com/cjheath/ruby/commit/ea99527feaf7dd06b3e8433ec640238441b188db In particular, I'd like to know the following: 1) Do you prefer that I move the literal strings (which occur once each) to #defined? https://github.com/cjheath/ruby/commit/ea99527feaf7dd06b3e8433ec640238441b188db#L1R1003 2) Will this line of code mess up the GC, and how should I fix that? https://github.com/cjheath/ruby/commit/ea99527feaf7dd06b3e8433ec640238441b188db#L1R3853 3) The set_parse_func is extern though it should be static, but I need to move the rb_define_global_function out of thread.c. Can someone please tell me where I should move it to, since there is no Init_Parser? https://github.com/cjheath/ruby/commit/ea99527feaf7dd06b3e8433ec640238441b188db#L1R9029 https://github.com/cjheath/ruby/commit/ea99527feaf7dd06b3e8433ec640238441b188db#L3R4705 4) I think I should change set_parse_func to accept a flags argument and a block, instead of assuming all flags, and taking a Proc. What are the downsides of using a block instead of a Proc (does this reduce the number of Bindings that get created)? How do I change set_parse_func to use a block? The initial implementation of Twister is an extension to RSpec which adds the option "--twist file-or-dir". It's still a bit rough - it needs to change the reporting on the twisted runs that follow the first (untwisted) run - but it does prove then concept. Clifford Heath, Data Constellation, http://dataconstellation.com Agile Information Management and Design.