- It does not seem universal enough to put it in liblangutil but in the scope of yul-phaser it's generic enough so I'm going to keep it together with Program.
- Giving the function ownership of an object and then receiving back another object is better than letting it implicitly modify data passed in an argument.
- I need some sample .yul files for testing but I see that existing tests generally have source code hard-coded in them rather than in standalone .yul files. There are lots of .yul files but they seem to be automatically processed by a special test case rather loaded ad-hoc by manually created tests.
- Program and Population required a file name until now. I'm making them accept loaded source code to be able to give them data hard-coded in a test.
