parinfer-mode for Emacs might be neat for encouraging Lisp adoption

parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[Christopher Allan Webber]

Here's a project borrowing some neat ideas from Emacs and extensions
(especially paredit) on lisp editing and providing some of its own
ideas, too:

  http://shaunlebron.github.io/parinfer/index.html

I could imagine this could make GNU Emacs an even better lisp hacking
environment for some than it already is, or make jumping in easier, for
some people.  Maybe someone will be inspired and add a plugin for it?
There's a space listed for editor implementations here:

  http://shaunlebron.github.io/parinfer/index.html#editor-plugins

I don't have time to work on this, but I imagine someone on this list
might find it interesting enough to take for a spin, so I thought I'd
post it here.  At the very least, it's clearly critical for GNU Emacs to
be the most advanced lisp editing environment there is. ;)

 - Chris

Re: parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[Marcin Borkowski]

On 2015-11-12, at 00:30, Christopher Allan Webber <cwebber@dustycloud.org> wrote:

> Here's a project borrowing some neat ideas from Emacs and extensions
> (especially paredit) on lisp editing and providing some of its own
> ideas, too:
>
>   http://shaunlebron.github.io/parinfer/index.html
>
> I could imagine this could make GNU Emacs an even better lisp hacking
> environment for some than it already is, or make jumping in easier, for
> some people.  Maybe someone will be inspired and add a plugin for it?
> There's a space listed for editor implementations here:
>
>   http://shaunlebron.github.io/parinfer/index.html#editor-plugins
>
> I don't have time to work on this, but I imagine someone on this list
> might find it interesting enough to take for a spin, so I thought I'd
> post it here.  At the very least, it's clearly critical for GNU Emacs to
> be the most advanced lisp editing environment there is. ;)

Oleh's lispy does a similar (though not identical) thing.

>  - Chris

Best,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University

Re: parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[Oleh Krehel]

Marcin Borkowski <mbork@mbork.pl> writes:

> On 2015-11-12, at 00:30, Christopher Allan Webber <cwebber@dustycloud.org> wrote:
>
>> Here's a project borrowing some neat ideas from Emacs and extensions
>> (especially paredit) on lisp editing and providing some of its own
>> ideas, too:
>>
>>   http://shaunlebron.github.io/parinfer/index.html
>>
>> I could imagine this could make GNU Emacs an even better lisp hacking
>> environment for some than it already is, or make jumping in easier, for
>> some people.  Maybe someone will be inspired and add a plugin for it?
>> There's a space listed for editor implementations here:
>>
>>   http://shaunlebron.github.io/parinfer/index.html#editor-plugins
>>
>> I don't have time to work on this, but I imagine someone on this list
>> might find it interesting enough to take for a spin, so I thought I'd
>> post it here.  At the very least, it's clearly critical for GNU Emacs to
>> be the most advanced lisp editing environment there is. ;)
>
> Oleh's lispy does a similar (though not identical) thing.

I've looked through the Parinfer web page and I don't think it's a great
idea (it's a neat trick though):

- It doesn't solve the problem of pasting unbalanced code.
- It relies on indentation to guess the thing to do.
- The thing to do might be surprising.
+ It balances parens for potentially generic commands that know nothing
  of Parinfer.

I think the first 3 negative points probably outweigh the single
positive point. Still, it would be cool to try it if anyone is up for
implementing it.

By the way, is anyone else on emacs-devel using lispy?  It's a really
cool way to quickly navigate, edit, examine, and debug Elisp.  It was
intended to be an easier Paredit, so picking it up shouldn't be too
hard, but it will probably take a long while to pick up everything and
reach top efficiency. See https://github.com/abo-abo/lispy if you're
interested.

It also has a bunch of integration tests (I saw this discussed in a
recent thread). The tests look like this:

    (should (string= (lispy-with "(|(a) (b) (c))" "j")
                     "((a) |(b) (c))"))

The parts are:

1. The buffer state before, including point and mark.
2. The user input.
3. The buffer state after, including point and mark.

There are around 700 of these tests and they run very fast, around 1.5s
to finish all of them. I think it would be cool for ERT to have this
kind of interface, and functions like `forward-list', `up-list',
`beginning-of-defun' etc could be tested this way.

These type of tests are also a good way to learn new bindings (since
they're built into the test), and what they should do in specific
situations (since it's not easy for the user to experience each
situation which results in a different branch taken by the command in
question).

Re: parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[Marcin Borkowski]

On 2015-11-13, at 12:32, Oleh Krehel <ohwoeowho@gmail.com> wrote:

> Marcin Borkowski <mbork@mbork.pl> writes:
>
>> Oleh's lispy does a similar (though not identical) thing.
>
> I've looked through the Parinfer web page and I don't think it's a great
> idea (it's a neat trick though):
>
> - It doesn't solve the problem of pasting unbalanced code.
> - It relies on indentation to guess the thing to do.
> - The thing to do might be surprising.
> + It balances parens for potentially generic commands that know nothing
>   of Parinfer.

Interesting thoughts.  I'd agree with the first one and the third one -
the second one might be a plus for some folks, and with experience you'd
be less and less surprised by various behaviors.  (BTW, lispy can be
a bit surprising too!)

> I think the first 3 negative points probably outweigh the single
> positive point. Still, it would be cool to try it if anyone is up for
> implementing it.

Not me, definitely.

> By the way, is anyone else on emacs-devel using lispy?  It's a really
> cool way to quickly navigate, edit, examine, and debug Elisp.  It was
> intended to be an easier Paredit, so picking it up shouldn't be too
> hard, but it will probably take a long while to pick up everything and
> reach top efficiency. See https://github.com/abo-abo/lispy if you're
> interested.

Hear, hear!

I definitely do not use even 10% of the power of lispy; still, if only
for hjkl, f, () and <> commands, it's a huge boost!  Also, C is quite
useful.  And q, of course - it's a huge time-and-keystroke-saver.  Also
[] and {}, and " (especially with an active region!).  Only recently did
I learn about sw (cool!), and I use xi/xc from time to time (and not
only to show off when I show Emacs to my coworkers!), and that's pretty
much it as far as my usage goes (at least now).

In fact, I have a blog post on Lispy in the pipeline (it will still have
to wait a few weeks probably).

And a funny thing is that after learning (the basics of) lispy, I want
to have more vim-like, one-finger keystrokes (no C-/M- for common tasks)
- I plan to define a few hydras for navigation in e.g. LaTeX documents.

Oleh, thanks for this great package!

> It also has a bunch of integration tests (I saw this discussed in a
> recent thread). The tests look like this:
>
>     (should (string= (lispy-with "(|(a) (b) (c))" "j")
>                      "((a) |(b) (c))"))
>
> The parts are:
>
> 1. The buffer state before, including point and mark.
> 2. The user input.
> 3. The buffer state after, including point and mark.
>
> There are around 700 of these tests and they run very fast, around 1.5s
> to finish all of them. I think it would be cool for ERT to have this
> kind of interface, and functions like `forward-list', `up-list',
> `beginning-of-defun' etc could be tested this way.
>
> These type of tests are also a good way to learn new bindings (since
> they're built into the test), and what they should do in specific
> situations (since it's not easy for the user to experience each
> situation which results in a different branch taken by the command in
> question).

And that I didn't know.  Cool, too!

Best,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University

Re: parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[João Távora]

Hi Oleh, Christopher, Marcin

What do you think of this prototype?

    (defun joaot/setup-some-parinfer-fanciness ()
      (add-hook 'post-self-insert-hook 'joaot/reindent-up 'append 'local))

    (add-hook 'lisp-mode-hook 'joaot/setup-some-parinfer-fanciness)

    (defun joaot/reindent-up ()
      (ignore-errors
        (save-excursion
          (backward-up-list) (indent-sexp))))

Now in some lisp-mode, type

   (defun parinfer ()
     (let ((foo bar)
           (baz quux))))

Change the `let' to `let*' and watch the auto-reindentation
magic. Probably very slow, but a cool trick nonetheless right?

This is useful is other languages, right? Couldn't JSON benefit from
something like this too?

> - It doesn't solve the problem of pasting unbalanced code.

IMO the problem of pasting unbalanced code is best solved by leaving it
alone, and using `electric-pair-mode's paren-balancing heuristic (on by
default), which is like paredit, but without the restraining order. And
no need to learn new commands.

Have you tried it, Oleh? Any feelings on how it could be improved?

Works for every language defining one or multiple parenthesis
syntaxes. Just like the hack above.

Personally I haven't tried lispy, basically because I want uniform
interfaces for all languages, even non-programming ones. I don't want to
re-learn shortcuts when I switch from lisp to JSON.

For that, I stick to, and am reasonably happy with, traditional sexp
navigation, the C-M-* family of movement/edition commands. Whoever came
up with those deserves some love.

On Fri, Nov 13, 2015 at 11:32 AM, Oleh Krehel <ohwoeowho@gmail.com> wrote:
> Marcin Borkowski <mbork@mbork.pl> writes:
>
>> On 2015-11-12, at 00:30, Christopher Allan Webber <cwebber@dustycloud.org> wrote:
>>
>>> Here's a project borrowing some neat ideas from Emacs and extensions
>>> (especially paredit) on lisp editing and providing some of its own
>>> ideas, too:
>>>
>>>   http://shaunlebron.github.io/parinfer/index.html
>>>
>>> I could imagine this could make GNU Emacs an even better lisp hacking
>>> environment for some than it already is, or make jumping in easier, for
>>> some people.  Maybe someone will be inspired and add a plugin for it?
>>> There's a space listed for editor implementations here:
>>>
>>>   http://shaunlebron.github.io/parinfer/index.html#editor-plugins
>>>
>>> I don't have time to work on this, but I imagine someone on this list
>>> might find it interesting enough to take for a spin, so I thought I'd
>>> post it here.  At the very least, it's clearly critical for GNU Emacs to
>>> be the most advanced lisp editing environment there is. ;)
>>
>> Oleh's lispy does a similar (though not identical) thing.
>
> I've looked through the Parinfer web page and I don't think it's a great
> idea (it's a neat trick though):
>
> - It doesn't solve the problem of pasting unbalanced code.
> - It relies on indentation to guess the thing to do.
> - The thing to do might be surprising.
> + It balances parens for potentially generic commands that know nothing
>   of Parinfer.
>
> I think the first 3 negative points probably outweigh the single
> positive point. Still, it would be cool to try it if anyone is up for
> implementing it.
>
> By the way, is anyone else on emacs-devel using lispy?  It's a really
> cool way to quickly navigate, edit, examine, and debug Elisp.  It was
> intended to be an easier Paredit, so picking it up shouldn't be too
> hard, but it will probably take a long while to pick up everything and
> reach top efficiency. See https://github.com/abo-abo/lispy if you're
> interested.
>
> It also has a bunch of integration tests (I saw this discussed in a
> recent thread). The tests look like this:
>
>     (should (string= (lispy-with "(|(a) (b) (c))" "j")
>                      "((a) |(b) (c))"))
>
> The parts are:
>
> 1. The buffer state before, including point and mark.
> 2. The user input.
> 3. The buffer state after, including point and mark.
>
> There are around 700 of these tests and they run very fast, around 1.5s
> to finish all of them. I think it would be cool for ERT to have this
> kind of interface, and functions like `forward-list', `up-list',
> `beginning-of-defun' etc could be tested this way.
>
> These type of tests are also a good way to learn new bindings (since
> they're built into the test), and what they should do in specific
> situations (since it's not easy for the user to experience each
> situation which results in a different branch taken by the command in
> question).
>



-- 
João Távora

Re: parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[Marcin Borkowski]

On 2015-11-13, at 16:34, João Távora <joaotavora@gmail.com> wrote:

> Hi Oleh, Christopher, Marcin
>
> What do you think of this prototype?
>
>     (defun joaot/setup-some-parinfer-fanciness ()
>       (add-hook 'post-self-insert-hook 'joaot/reindent-up 'append 'local))
>
>     (add-hook 'lisp-mode-hook 'joaot/setup-some-parinfer-fanciness)
>
>     (defun joaot/reindent-up ()
>       (ignore-errors
>         (save-excursion
>           (backward-up-list) (indent-sexp))))
>
> Now in some lisp-mode, type
>
>    (defun parinfer ()
>      (let ((foo bar)
>            (baz quux))))
>
> Change the `let' to `let*' and watch the auto-reindentation
> magic. Probably very slow, but a cool trick nonetheless right?

I'll try it later!

> This is useful is other languages, right? Couldn't JSON benefit from
> something like this too?
>
>> - It doesn't solve the problem of pasting unbalanced code.
>
> IMO the problem of pasting unbalanced code is best solved by leaving it
> alone, and using `electric-pair-mode's paren-balancing heuristic (on by
> default), which is like paredit, but without the restraining order. And
> no need to learn new commands.

BTW, lispy's M command also (kind of) solves that.

> Have you tried it, Oleh? Any feelings on how it could be improved?
>
> Works for every language defining one or multiple parenthesis
> syntaxes. Just like the hack above.
>
> Personally I haven't tried lispy, basically because I want uniform
> interfaces for all languages, even non-programming ones. I don't want to
> re-learn shortcuts when I switch from lisp to JSON.
>
> For that, I stick to, and am reasonably happy with, traditional sexp
> navigation, the C-M-* family of movement/edition commands. Whoever came
> up with those deserves some love.

That is also a good point.  (But I use lispy nevertheless.)

Best,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University

Re: parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[Marcin Borkowski]

On 2015-11-13, at 16:34, João Távora <joaotavora@gmail.com> wrote:

> Hi Oleh, Christopher, Marcin
>
> What do you think of this prototype?
>
>     (defun joaot/setup-some-parinfer-fanciness ()
>       (add-hook 'post-self-insert-hook 'joaot/reindent-up 'append 'local))
>
>     (add-hook 'lisp-mode-hook 'joaot/setup-some-parinfer-fanciness)
>
>     (defun joaot/reindent-up ()
>       (ignore-errors
>         (save-excursion
>           (backward-up-list) (indent-sexp))))

BTW, using this with idle timers would make it much smoother, I guess.

Best,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University

Re: parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[João Távora]

On Fri, Nov 13, 2015 at 3:58 PM, Marcin Borkowski <mbork@mbork.pl> wrote:
>
> On 2015-11-13, at 16:34, João Távora <joaotavora@gmail.com> wrote:
>
>> Hi Oleh, Christopher, Marcin
>>
>> What do you think of this prototype?
>>
>>     (defun joaot/setup-some-parinfer-fanciness ()
>>       (add-hook 'post-self-insert-hook 'joaot/reindent-up 'append 'local))
>>
>>     (add-hook 'lisp-mode-hook 'joaot/setup-some-parinfer-fanciness)
>>
>>     (defun joaot/reindent-up ()
>>       (ignore-errors
>>         (save-excursion
>>           (backward-up-list) (indent-sexp))))
>
> BTW, using this with idle timers would make it much smoother, I guess.

Probably. Also Oleh just pointed out that it's basically what
agressive-indent-mode (on MELPA, probably) already does...

-- 
João Távora

Re: parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[Stefan Monnier]

> Probably. Also Oleh just pointed out that it's basically what
> agressive-indent-mode (on MELPA, probably) already does...

No, it's on GNU ELPA ;-)


        Stefan

Re: parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[João Távora]

On Fri, Nov 13, 2015 at 3:34 PM, Oleh Krehel <ohwoeowho@gmail.com> wrote:
> João Távora <joaotavora@gmail.com> writes:
>
>> Hi Oleh,
>>
>> What do you think of this prototype?

> I think this is what `aggresive-indent-mode' does. Additionally "DEL" on
> `let*' doesn't work for me for some reason.

Ahaha. Right. That's what I get for not reading up on prior art :-)

> I've disabled it long time ago, since I use lispy. But I tried just now
> and the interactive variant of this doesn't work in `electric-pair-mode':
>
> (progn
>   (kill-new "(foo")
>   (yank))

What do you mean, it doesn't work what did you expect to happen?

electric-pair-mode only kicks in when inserting parenthesis interactively.

> The thing with lispy is that you get /extra/ free shortcuts only for
> LISP. These free shortcuts are possible to get only for LISP because of

To be fair to lispy, probably also for JSON and some other languages.

> the
> The first `forward-list' will work fine, but the second one will
> throw. Why not just call `up-list' in that case?
> "]" (`lispy-forward') is `forward-list' with exactly that modification.

I like that it forbids me to go past the end of the list. I even use that
for programming without looking at the computer. Just forward list a
million times until you hear the bell.

I understand lispy's convenience philosophy, but it's undeniable that
it expands the instruction set. I'm after the low hanging fruit: keep
the same reduced instruction set and have Emacs resonably guess
what I'm trying to do.

-- 
João Távora

Re: parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[Oleh Krehel]

João Távora <joaotavora@gmail.com> writes:

> On Fri, Nov 13, 2015 at 3:34 PM, Oleh Krehel <ohwoeowho@gmail.com> wrote:
>> João Távora <joaotavora@gmail.com> writes:
>>
>>> Hi Oleh,
>>>
>>> What do you think of this prototype?
>
>> I think this is what `aggresive-indent-mode' does. Additionally "DEL" on
>> `let*' doesn't work for me for some reason.
>
> Ahaha. Right. That's what I get for not reading up on prior art :-)
>
>> I've disabled it long time ago, since I use lispy. But I tried just now
>> and the interactive variant of this doesn't work in `electric-pair-mode':
>>
>> (progn
>>   (kill-new "(foo")
>>   (yank))
>
> What do you mean, it doesn't work what did you expect to happen?

Well, suppose it was Parinfer-like. Then it would either modify "(foo"
to either "foo" or "(foo)". That's what I meant: automatic re-balancing
after each buffer change.

> electric-pair-mode only kicks in when inserting parenthesis interactively.

I understand. I'm saying that neither Parinfer, nor lispy, nor
electic-pair-mode solves the problem of pasting "(foo".

>> The thing with lispy is that you get /extra/ free shortcuts only for
>> LISP. These free shortcuts are possible to get only for LISP because of
>
> To be fair to lispy, probably also for JSON and some other languages.

You can enable lispy for JSON. I just checked, "C" (`lispy-convolute')
still works. Even "w" (`lispy-move-up') sort-of works :)

>> the
>> The first `forward-list' will work fine, but the second one will
>> throw. Why not just call `up-list' in that case?
>> "]" (`lispy-forward') is `forward-list' with exactly that modification.
>
> I like that it forbids me to go past the end of the list. I even use that
> for programming without looking at the computer. Just forward list a
> million times until you hear the bell.

Also a feature in lispy: "99j" or "999]" or "99>" will not exit the
parent list.

> I understand lispy's convenience philosophy, but it's undeniable that
> it expands the instruction set. I'm after the low hanging fruit: keep
> the same reduced instruction set and have Emacs resonably guess
> what I'm trying to do.

It's a reasonable choice, although I made a different one.
What I try to do is to use an extended instruction set until I sieve out
a super-efficient subset of that instruction set.

For example, "j" is usually a better command than "C-M-n". In plain
Emacs terms, from the left paren, "j" translates to "C-M-n C-M-n C-M-p",
i.e. it selects the next sexp while staying on the same side (left or
right).

Re: parinfer-mode for Emacs might be neat for encouraging Lisp adoption

[Christopher Allan Webber]

Christopher Allan Webber writes:

> Here's a project borrowing some neat ideas from Emacs and extensions
> (especially paredit) on lisp editing and providing some of its own
> ideas, too:
>
>   http://shaunlebron.github.io/parinfer/index.html
>
> I could imagine this could make GNU Emacs an even better lisp hacking
> environment for some than it already is, or make jumping in easier, for
> some people.  Maybe someone will be inspired and add a plugin for it?
> There's a space listed for editor implementations here:
>
>   http://shaunlebron.github.io/parinfer/index.html#editor-plugins
>
> I don't have time to work on this, but I imagine someone on this list
> might find it interesting enough to take for a spin, so I thought I'd
> post it here.  At the very least, it's clearly critical for GNU Emacs to
> be the most advanced lisp editing environment there is. ;)
>
>  - Chris

By the way, I had the good fortune to meet Shaun in person.  He was very
interested in seeing an emacs mode.  We talked a bit, I gave him some
pointers to some of the existing parenthesis navigation functions inside
of emacs.  Since then the Parinfer team (Shaun Williams and Chris
OakMan) have started some serious work on an emacs port:

  https://github.com/oakmac/parinfer-elisp

However, they aren't emacs users, and expressed they'd like help and
testing.  So there you are, if anyone is interested in diving in!

 - Chris