[roryokane]

> The post says that.

I think the grandparent knew that, and was just repeating what you said to contrast it with his following statement about what static typing is good for.

And dot-completion is not completely unique to static languages, but I would say it is “particularly unique” – it is more common for static languages. And that’s not just coincidence – it is generally easier to write a tool like dot-completion for a static language than a dynamic language, because dot-completion involves static analysis of the code.

[derefr]

> dot-completion involves static analysis of the code.

Dot-completion involves having a living model of the program loaded in memory. You can do this with any language--static languages just partition the program model such that you get a certain phase of interpretation (compilation) past which you have a completed model of all of the code, without yet having seen any of the data.

On the other hand, you can easily dot-complete method calls in a dynamic language's REPL--because there, at runtime, is when and where a dynamic language forms a complete model of the program it can use to do such things.

Now, the real question is why we're still programming dynamic languages in text-editors instead of treating them as congealments of transactionally-replayable interactive REPL transcripts. (Are there any modern examples of programming in this style, anyway? I can only think of ancient ones: Emacs Lisp, Squeak Smalltalk, and the "immediate-command-line" of some Telnet-based simulated-world MOOs.)

[prodigal_erik]

When you create a method which takes an argument in a dynamic language, there's no declaration of the type of that argument or which methods it will be known to support. So how does dot-completion work for any target other than "this"? The REPL isn't doing whole-program dataflow analysis to infer the only type(s) which could possibly be passed, is it?

[jules]

FYI, PyTools for Visual Studio does dataflow analysis for intellisense.

[carsongross]

I code in both ruby (with a repl in the IDE) and java (with a traditional statically typed IDE). There are times I wish I had a repl in java (I typically use debugging in a test to fake it) but I'd give my left cortex for reliable code completion in ruby.

There's no reason we can't have both. It just takes a reasonable terse statically typed language like C# or, dare I say... gosu.

[jshen]

Have you tried pry for ruby?