Re: Changes to completing-read

[Stefan Monnier]

> It looks like the function gets called four times when the user presses
> TAB, and the only difference between the four calls is the last
> argument. t, nil, 'lambda, and the cons (boundaries . "") are
> passed. According to the docstrings of try-completion and
> all-completions, t and nil should be passed to the collection function
> when those two functions get called as part of the completion process
> somehow. But I have no idea where 'lambda or (boundaries . "") are
> coming from.

The `lambda' is when the function is called by `test-completion'.
The `boundaries' is a new functionality, still undocumented.

> It's rather unclear from the docstrings, but from what I can piece
> together, the "collection" function should act totally differently based
> on the value of the third argument.

That's right.  A better way to think of it might be that the "function"
is an object (in the OO sense), and the last arg is the method to
be executed.


        Stefan