From: Theodor Thornhill <theo@thornhill.no>
To: Stefan Monnier <monnier@iro.umontreal.ca>, Yuan Fu <casouri@gmail.com>
Cc: emacs-devel@gnu.org, eliz@gnu.org
Subject: Re: Plug treesit.el into other emacs constructs
Date: Wed, 14 Dec 2022 17:24:52 +0100 [thread overview]
Message-ID: <EAAEC1C8-303C-4D9E-A6DE-A1C96101E0FB@thornhill.no> (raw)
In-Reply-To: <jwv359i85ii.fsf-monnier+emacs@gnu.org>
On 14 December 2022 15:01:55 CET, Stefan Monnier <monnier@iro.umontreal.ca> wrote:
>> I would argue that the purpose of forward-sexp is to move over items in
>> a list.
>
>There are different ways to look at it. In the Lisp context where it
>emerged, we only have "identifiers" and "parenthesized thingies", so
>that doesn't give much guidance about what to do in-between.
>
>The semantics I chose for SMIE is what I found to be closest to
>past practice.
>
>> Always going for the smallest subtree doesn’t seem to align with it.
>> Take that example above, going across the smallest subtree means
>> moving over X, then moving over “.”,
>
>No: when you're left of ".", as in "(X|.y(z), alpha)", the SMIE
>semantics of `forward-sexp` moves over ".y(z)", i.e. to
>"(X.y(z)|, alpha)"
>
>> that doesn’t feel like what forward-sexp should do to me.
>
>Indeed, moving just over "." would be very far from my understanding of
>what `forward-sexp` intends to do.
>
>> You mean in the following code
>>
>> int a = 0[1];
>> int b = 1;[2]
>>
>> Forward-sexp would move [1] to [2]?
>
>No, SMIE's `forward-sexp` moves from
>
> int a = 0|;
> int b = 1;
>
>to
>
> int a = 0;
> int b = 1|;
>
>[ You can try it by installing Tuareg and moving around in an OCaml
> file, for example. ]
>
>and when moving backward it moves from
>
> int a = 0;
> int b = 1;|
>
>to
>
> int a = 0;|
> int b = 1;
>
>> But if we move over the smallest
>> subtree, I’d imagine it only move across the semicolon after [1].
>
Doesn't this look like forward-sentence?
>In my view ";" is not a substree. It's the node of a substree.
>We can't actually move over a proper subtree in that case because there
>is no substree whose left boundary starts right before the ";", so the
>closest is to move over the ";" *plus* its right child.
>
>> Even if it moves from [1] to [2], needing to adjust point feels very
>> inconvenient to me, at least I wouldn’t want to use something
>> like that.
>
>Moving point is the way to tell SMIE's `forward-sexp` which level of the tree
>we want to navigate. I don't believe Emacs can reliably guess the right
>level, and I don't believe choosing an arbitrary level for the users
>serves them best either. I can imagine other ways to specify the
>intended tree level, tho: maybe we could have a kind of prefix command
>for that. E.g. a new command that would work a bit like `C-M-u` (or its
>younger sibling `expand-region`) but would only affect the next sexp
>command instead.
>
>> I want to type a single binding and move to where I want, and
>> type that binding multiple times to move multiple steps.
>
>I don't think a single binding can always jump to where you want.
>That would require magic :-)
>
>But yes, SMIE's `forward-sexp` does work well when repeated to jump over
>N instructions, it was indeed an important design goal.
>
>
> Stefan
>
next prev parent reply other threads:[~2022-12-14 16:24 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-12 14:33 Plug treesit.el into other emacs constructs Theodor Thornhill
2022-12-12 14:45 ` Eli Zaretskii
2022-12-13 18:17 ` Theodor Thornhill
2022-12-12 15:46 ` Stefan Monnier
2022-12-13 18:27 ` Theodor Thornhill
2022-12-13 19:37 ` Stefan Monnier
2022-12-13 19:53 ` Yuan Fu
2022-12-13 20:06 ` Perry Smith
2022-12-13 23:19 ` Stefan Monnier
2022-12-14 8:14 ` Yuan Fu
2022-12-14 8:42 ` Theodor Thornhill
2022-12-14 14:01 ` Stefan Monnier
2022-12-14 16:24 ` Theodor Thornhill [this message]
2022-12-14 17:46 ` Stefan Monnier
2022-12-14 18:07 ` Theodor Thornhill
2022-12-14 19:25 ` Stefan Monnier
2022-12-14 19:35 ` Stefan Monnier
2022-12-14 20:04 ` Theodor Thornhill
2022-12-14 20:50 ` Stefan Monnier
2022-12-14 21:15 ` Theodor Thornhill
2022-12-14 21:34 ` Stefan Monnier
2022-12-15 19:37 ` Theodor Thornhill
2022-12-15 19:56 ` Stefan Monnier
2022-12-15 20:03 ` Theodor Thornhill
2022-12-15 20:33 ` Theodor Thornhill
2022-12-15 20:57 ` Theodor Thornhill
2022-12-24 7:00 ` Eli Zaretskii
2022-12-24 8:44 ` Yuan Fu
2022-12-24 14:01 ` Stefan Monnier
2022-12-24 14:15 ` Theodor Thornhill
2022-12-26 19:11 ` Theodor Thornhill
2022-12-26 22:46 ` Stefan Monnier
2022-12-26 22:51 ` Stefan Monnier
2022-12-27 22:15 ` Theodor Thornhill via Emacs development discussions.
2022-12-28 0:12 ` Stefan Monnier
2022-12-28 9:26 ` Theodor Thornhill via Emacs development discussions.
2022-12-28 18:01 ` Stefan Monnier
2022-12-28 18:27 ` Theodor Thornhill
2022-12-26 22:56 ` Theodor Thornhill
2022-12-27 15:46 ` Lynn Winebarger
2022-12-14 23:31 ` Yuan Fu
2022-12-15 0:05 ` Yuan Fu
2022-12-15 7:09 ` Eli Zaretskii
2022-12-15 7:14 ` Theodor Thornhill
2022-12-15 4:37 ` Stefan Monnier
2022-12-15 5:59 ` Theodor Thornhill
2022-12-15 21:23 ` Yuan Fu
2022-12-15 21:28 ` Theodor Thornhill
2022-12-13 20:02 ` Theodor Thornhill
2022-12-13 23:10 ` Stefan Monnier
2022-12-14 23:32 ` Stephen Leake
2022-12-16 10:02 ` Kévin Le Gouguec
2022-12-16 11:54 ` [SPAM UNSURE] " Stephen Leake
2022-12-17 15:30 ` Kévin Le Gouguec
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