RE: Why doesn't Info `T' cache node tree for current file?

[Drew Adams]

> >> It is not very quick, since the code has to reread all 
> >> Info subfiles (its slowest part).
> >
> > That was my thinking - it really does seem to do quite a 
> > lot of work.
> >
> > On the other hand, at least with the manuals I use (Emacs 
> > and Elisp), it seems pretty snappy to me. Do you really see
> > a performance problem, or is this just hypothetical?
> 
> If you have a fast machine, this doesn't mean everyone has the same.
> Try on at least 300MHz proc to see how quick it is.

I won't be trying a different machine, but perhaps someone else can.

Can you point to a particular manual for which this is unacceptably slow on a
slow machine? IOW, can you point to a concrete case that people with slow
machines can check?

> >> I see one problem: how to refresh the cached TOC buffer when
> >> the Info file changes
> >
> > Do you mean when you go to a different manual (different 
> > file), or do you mean when someone changes the file on disk?
> >
> > I think we can ignore the latter (no?).
> 
> The same Info file doesn't change too often, but there are 
> situations when for instance, the user writes a new Info
> manual, and in the process of writing uses the TOC as an
> overview of the manual (i.e. iterations like
> add a new node, revisit the TOC, reorganize its structure, and so on).

Ah, I see - the use case is for Info manual writers.

That is important, but it is still a minority use case. Perhaps those people
could live with restarting Emacs. Or perhaps they could just delete the cache
manually so that it gets rebuilt. IOW, do you really think this is an important
enough use case to worry about?