RE: read-file-name-predicate

[Drew Adams]

>     `read-file-name-predicate' has an external,
>     Lisp behavior: During completion, Lisp code can check what
>     the predicate is or even change the predicate. Shouldn't that
>     be documented?
>
> I see no reason to document it at present.
> It is meant for internal use only.

How is it different from `minibuffer-completion-predicate'? I see the two as
parallel.

Without this variable, how can you do, for file-name completion, what you
might do for non-file-name completion using
`minibuffer-completion-predicate'? Why document one but not the other?