Re: Pending contents in org documents (Re: Asynchronous blocks for everything (was Re: ...))

[Ihor Radchenko <yantar92@posteo.net>]

Bruno Barbier <brubar.cs@gmail.com> writes:

> I've pushed the modification to my branch.

Thanks! Let's work further on the top comment.

> ;; To lock a region, you need to do something like this:

I think "something like this" can be just dropped.

> ;;    1. Call the function `org-pending' with the region to lock; use
> ;;       the ON-OUTCOME argument to tell Emacs how to update the
> ;;       region.  Keep the returned REGLOCK (you'll need it to send
> ;;       updates).

It would be nice to provide examples of `org-pending' call right in the
top comment. Ideally, the example should also show how to modify REGLOCK
fields to customize its behaviour.

> ;;    2. Start "something" that computes the new content.  That
> ;;       "something" may be a thread, a timer, a notification, a
> ;;       process, etc.  That "something" must eventually send a
> ;;       :success or :failure message (using
> ;;       `org-pending-send-update'): Emacs will update the pending
> ;;       region (using your ON-OUTCOME) and unlock it; at this point
> ;;       the lock is "dead" (not live-p).

Please also add information about sending updates to the REGLOCK, with
examples. Otherwise, "receiving progress" in the next section is
surprising.

> ... (not live-p)

Please name `org-pending-reglock-live-p' - it is more clear than forcing
the readers search it themselves.

> ;;;; Interface provided to the Emacs user
> ;;
> ;; The library makes locks visible to the user using text properties
> ;; and/or overlays.  It diplays and updates the status while the
> ;; region is locked: the initial status is "scheduled", then, when

It would be nice to name `org-pending-reglock-status' here and use the
actual status values - :scheduled, :pending, :success, :failure.
Ideally, in table/list explaining what happens with buffer text,
overlays, and user interaction, when REGLOCK has each of the listed
status values.

> ;; receiving progress it becomes "pending" (with progress information
> ;; if any).  Emacs allows to diplay a description of the lock.  From
> ;; that description, the user may request to cancel that lock; see the
> ;; field `user-cancel-function' of the REGLOCK object if you need to
> ;; customize what to do on cancel.

It is not very clear how user can interact with "description". Is it a
tooltip? A window? Something else? Please give a bit more details.

Also, when "cancel" is requested, it is a good idea to state that
`user-cancel-function' is called and describe what it does by default.

> ;; When receiving the outcome (success or failure), after unlocking
> ;; the region, the library may leave information about the outcome

"may"?? Or does it always leave the information (by default)?

> ;; (using text properties/overlays).  If that outcome information is
> ;; (still) displayed, Emacs allows to display a description of that
> ;; lock.  From that description, the user may decide to "forget" that
> ;; lock; "forgetting the lock" removes the outcome visual marks, and,

Is "forgetting" customizeable like `user-cancel-function'?

> ;; it allows Emacs to discard any information related to this lock.

What does it mean?

> ;; The description of a lock (live or dead) provides information like
> ;; the schedule time, the duration, the outcome time, the result (in
> ;; case of success), the error (in case of failure), etc.  Customize
> ;; the field `insert-details-function' of REGLOCK object to add your
> ;; own information.

Please show an example how to do it here.

> ;; If the user kills a buffer, or, kills Emacs, some locks may have to
> ;; be killed too be killed too.  The library will ask the user to
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
typo

> ;; confirm if an operation requires to kill some locks.  See the field
> ;; `before-kill-function' of REGLOCK object, if you need to do
> ;; something before a lock is really killed.

Again, an example would be helpful.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>