bug#59730: gdb-mi.el: Local variables reordering

Den tors 1 dec. 2022 kl 21:40 skrev Gustaf Waldemarson <gustaf.waldemarson@gmail.com>:

> First, if the problem is that the type names are long, maybe it will be
> enough to truncate them without changing the order?

The truncation is the main issue, although I would argue that this is also a good opportunity to change
the order as well given some of the benefits of a left-to-right reading order, (e.g., it is easier to read and
parse, as explained Herb Sutter^1). Other languages such as Rust/Go could also benefit from this. That said,
I guess this might be a western thing, and it is hardly a hill I would die on, so to speak.

> Also, latest version of GDB allow control on which types get shown in full
> and which are shown as <...> -- did you try to use that GDB option to make
> the display more easily readable?

I was not aware of this. I will look into it and see if I can enable it. That said, there's probably benefits to having
the option to truncate from Emacs anyways, primarily to support older versions of GDB.

> And wouldn't it be better to truncate the string with
> truncate-string-to-width or with string-truncate-left instead?

Absolutely, I just was not aware of these (better) tools. One could even argue that a custom filter-function could be warranted,
but I think that's a bit overkill right now at least.

> And finally, when the type is truncated, would it be possible to add a
> tooltip with the full name of the type, so that users who need that could
> hover the mouse above the truncated type and see it in full?

Excellent idea, that should be doable by just adding some properties to the strings, I'll see if I can sort these things out as well.

Thanks for the feedback, I'll start working on an updated patch soon-ish

^1. See e.g. https://softwareengineering.stackexchange.com/questions/101978/advantages-of-a-left-to-right-language-syntax
^1. and https://herbsutter.com/2011/05/04/interview-on-channel-9-2/

Best regards,
Gustaf

Den tors 1 dec. 2022 kl 16:45 skrev Eli Zaretskii <eliz@gnu.org>:
> From: Gustaf Waldemarson <gustaf.waldemarson@gmail.com>
> Date: Wed, 30 Nov 2022 23:09:14 +0100
>
> In summary, this patch does this: In gdb-mi.el mode, for local C/C++ variables that were previously written
> out:
>
> - | type | name | value|
>
> Now write them out as:
>
> - | name | type | value |
>
> Additionally, cap the string length of the name and type to `gdb-locals-max-name-length` and
> `gdb-locals-max-type-length` respectively (new custom variables with a default set to 20). I also changed the
> table to always left-align the values when we're printing the locals.
>
> Turns out it was really easy to fix, but I may have missed some subtleties, so feel free to give it a look or
> start a discussion whether this is a good idea or not. I personally prefer it this way since it is much easier
> and faster to see the values of individual variables, especially when the type-info get very long.

First, if the problem is that the type names are long, maybe it will be
enough to truncate them without changing the order?

Also, latest version of GDB allow control on which types get shown in full
and which are shown as <...> -- did you try to use that GDB option to make
the display more easily readable?

And wouldn't it be better to truncate the string with
truncate-string-to-width or with string-truncate-left instead?

And finally, when the type is truncated, would it be possible to add a
tooltip with the full name of the type, so that users who need that could
hover the mouse above the truncated type and see it in full?

Thanks.

From:	Gustaf Waldemarson
Subject:	bug#59730: gdb-mi.el: Local variables reordering
Date:	Thu, 1 Dec 2022 22:53:26 +0100