Make haskell-font-lock-symbols-alist into a customizable variable.

[sheganinans]

No description provided.

[gracjan]

What does this pr do?

[sheganinans]

Arrow syntax uses the (&&&) operator, currently haskell-mode makes it look
like (∧&) because of the line right underneath it.

On Wed, Jun 10, 2015 at 11:16 PM, gracjan notifications@github.com wrote:

What does this pr do?

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#713 (comment).

[geraldus]

I'm interest is there a unicode substitution for &&&?

[sheganinans]

I don't know, although with a quick search I was able to find the asterism ⁂
U+2042 http://en.wikipedia.org/wiki/Asterism_%28typography%29 Which seems
to me like a great unicode replacement for the (***) operator!

On Wed, Jun 10, 2015 at 11:27 PM, Артур Файзрахманов <
notifications@github.com> wrote:

I'm interest is there a unicode substitution for &&&?

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#713 (comment).

[gracjan]

In this case we need to stop doing it. We have code that tries to prevent &&& problems.

[sheganinans]

Oh, I didn't know there was something in the works for the (&&&) problem.

I also pushed a replacement for (***), although I can put it in a separate PR if you want.

[sheganinans]

There is also the upside down ampersand, ⅋, what do you think about that
geraldus?

On Wed, Jun 10, 2015 at 11:41 PM, gracjan notifications@github.com wrote:

In this case we need to stop doing it. We have code that tries to prevent
&&& problems.

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#713 (comment).

[sheganinans]

If it was up to me, I'd like for either just the ("&&&" . "&&&") hack or
both ("&&&" . "⅋" ) and ("***" . "⁂") . To keep the syntax symmetric, since
it would be a shame if one of the operators only took up a single space and
the other three. I'd just rather have both take up three if we aren't going
to have either.

On Wed, Jun 10, 2015 at 11:48 PM, Aistis Raulinaitis sheganinans@gmail.com
wrote:

There is also the upside down ampersand, ⅋, what do you think about that
geraldus?

On Wed, Jun 10, 2015 at 11:41 PM, gracjan notifications@github.com
wrote:

In this case we need to stop doing it. We have code that tries to prevent
&&& problems.

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#713 (comment)
.

[geraldus]

@sheganinans I totally agree with your last comment, however I'm quite unfamiliar with arrows and can't be certain about ⅋. If this is used for fanout arrow (is it right name?) in the algebraic literature or by Haskell community I'll vote for this. Same for ⁂.

[geraldus]

@gracjan if I understood correctly, this is something like hack rather than actual solution. I have not looked at unicode stuff myself yet, so can you point the right place to be updated?

Also I think we can keep this PR for better substitutions if offered changes are acceptable.

[gracjan]

Note that original problem that &&& got composed in half is a long fixed problem, specifically in the line https://github.com/haskell/haskell-mode/blob/master/haskell-font-lock.el#L136 and the issue #582.

@sheganinans: it should be working ok for you without your hack.

As about turning &&& and *** into something else: turn defconst haskell-font-lock-symbols-alist into defcustom and then people will be able to fix their own special cases.

[sheganinans]

Oh! Lovely, good to know. Yes, I must have been using a rather old version of haskell-mode. Otherwise, maybe we might want to get some sort of collective say on what people might want with arrow syntax? Say, we could propose the ⅋ and ⁂ changes on /r/haskell and see if maybe we get a better suggestion?

[geraldus]

I have no Reddit account, but it will be good to know community opinion.

[sheganinans]

I have one, I can post it if @gracjan gives the go ahead, he can obviously do it himself if he wants to.

[gracjan]

I remember that very long time ago this was discussed on haskell-cafe (mailing list). I do not remember there was an agreement.

Still I would prefer that we do:

• turn defconst into defcustom
• people that feel this is good idea try it on themselves first for a month, come back with experiences

The reason is that &&& and *** replacements are pretty esoteric characters that may interact in a strange way with fonts, emacs rendering machinery, general layout and overall feeling needs to be proven.

[sheganinans]

Alright, sounds good. I'd be satisfied with the defcustom proposal. I think it is a good balance between opening up the interface for people who want to add all sorts of unicode to their custom dsls and the people who would like to keep haskell-mode as vanilla as possible.

[gracjan]

@sheganinans: will you make a PR?

[sheganinans]

sure

[sheganinans]

Just a sec, I guess simply s/defconst/defcustom/ is not going to suffice. Reading the docs.

[gracjan]

Look in the builder:

In toplevel form:
haskell-font-lock.el:41:1:Error: defcustom for `haskell-font-lock-symbols-alist' fails to specify containing group
make: *** [haskell-font-lock.elc] Error 1

[sheganinans]

Yup, I got the same error. I should build my files before I commit them. :) I'm still figuring out the customization system in emacs.

[sheganinans]

Ok, I'm a little lost. I'm not sure exactly what the :type of the interface is supposed to be, I've tried :type '(alist :key-type string :value-type string) and a few others but it doesn't seem to work.

[gracjan]

I know about as much as you. Are there other modes for emacs that customize similar functionality?

[sheganinans]

I haven't done much emacs customization at all, so you know much more than me.

[gracjan]

This is good enough:

`sexp'
     The value may be any Lisp object that can be printed and read back.
     You can use `sexp' as a fall-back for any option, if you don't
     want to take the time to work out a more specific type to use.

[sheganinans]

Never mind, it was the right thing, I was simply loading the old version of the files and not the ones i was editing.

[sheganinans]

You may want some other :type, please change it to whatever interface you would prefer.

[gracjan]

This is good, thanks!

[sheganinans]

Thanks!