Re: [ELPA] New package: hierarchy

[joaotavora@gmail.com (João Távora)]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> Looking at the code I get the impression that it would be nice to split
> it into 3 parts:
> - the `hierarchy` defstruct with associated manipulation functions.
> - the display code.
> - an API between the two, which we could call `tree`, a bit like `seq.el`
>   defining the tree navigation primitives needed by the display code
>   and which could be implemented by all kinds of data types, including
>   the `hierarchy` struct.

FWIW there's also:

   https://www.emacswiki.org/emacs/tree-mode.el
   (and maybe some other similar package that I can't find right now).

Anyway, when I implemented a structured "trace" facility for Common
Lisp[1]] these libraries werent' very useful and I had to bake my own.

I had two (extraordinary?) requirements: (1) that it should work
asynchronously (i.e. updates to any arbitrary node in the hierarchy can
come at any time and out of order) and (2) that display is lazy
(i.e. collecting an update to an arbitrary part in the tree doesn't
necessarily display it).

This is why I favour Stefan's separation and I would love to replace my
library with a decent one.

João

[1]
https://github.com/joaotavora/sly/blob/master/contrib/sly-trace-dialog.el