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Comment by irahul | Hacker News Reader

> The tooling around dynamic languages is almost laughably primitive and limited in comparison.

Somethings just can't be done.

    class Foo:
        def foo():
            pass

    def bar(f):
        f.foo

If you re-factor Foo.foo to Foo.renamed, there is no way to know if the call in bar should be re-named as well.

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Sure there is. You just need code tracing and full test coverage. You can't do it from the source alone, sure, but that doesn't mean it can't be done.

> Sure there is. You just need code tracing and full test coverage. You can't do it from the source alone, sure, but that doesn't mean it can't be done.

The analog would be driving to New York from Bangalore. Sure it can be done if I arrange a car; have money for the fuel, food and stay; have all the papers etc etc. But that doesn't mean it is in any way comparable to flying to New York while watching a movie and sipping wine.

Renaming a method in the public interface is always a pain - your test coverage and code tracing can numb down it a bit, but it's going to be there. Some of it is because public interfaces are a constant for all practical intent and purpose; most of it is because of the case I listed above.

I think I might not have made myself clear - given an execution trace of a test suite with full coverage (or just something which exercises every code path - it doesn't have to be a test suite, but you've already got one of those so you might as well use it, right?), you could build a tool to make a rename refactoring fully automatic in a dynamic language. At the point of use, it would be identical to a static language rename, it would just work in a different way. It's a fairly obvious idea, so I presume this has been done in the past, but I don't know of any examples offhand.

The only gotcha is where you're eval'ing a string, but that's going to be nasty however you cut it.

Clippy could ask at least, right?

Joking aside, your example brought the nature of the issue to life; thanks.

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