[PATCH] emacs: devel: Add indentation rules for 'modify-phases' keywords.

[PATCH] emacs: devel: Add indentation rules for 'modify-phases' keywords.

[Alex Kost]

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Hello, currently Emacs indents our 'modify-phases' macro like this:


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(modify-phases %standard-phases
  (add-before 'build 'foo-phase
              (lambda _ 'foo)))

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or this:


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(modify-phases %standard-phases
  (add-before
   'build 'foo-phase
   (lambda _ 'foo)))

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While IMHO it is better to have it indented like this:


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(modify-phases %standard-phases
  (add-before 'build 'foo-phase
    (lambda _ 'foo)))

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This patch will do it.  Of course we can just use:

(put 'replace 'scheme-indent-function 1)
(put 'add-after 'scheme-indent-function 2)
(put 'add-before 'scheme-indent-function 2)

But potentially these keywords may also be used outside 'modify-phases'.

So with the attached more complex rules, 'replace', 'add-before' and
'add-after' keywords will be indented specially only when they are
inside 'modify-phases', otherwise they will be indented as usual:


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(modify-phases %standard-phases
  (replace 'build
    (lambda _ (zero? 0))))

(do-something
 (replace 'this
          'that
          'and-that))

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From 092dbb4460cf140c628eb4aeb4c5fff8f0083b3c Mon Sep 17 00:00:00 2001
From: Alex Kost <alezost@gmail.com>
Date: Sat, 17 Oct 2015 19:02:39 +0300
Subject: [PATCH] emacs: devel: Add indentation rules for 'modify-phases'
 keywords.

* emacs/guix-devel.el: Add indentation rules for 'modify-phases' keywords.
  (guix-devel-indent-modify-phases-keyword,
  guix-devel-indent-modify-phases-keyword-1,
  guix-devel-indent-modify-phases-keyword-2): New functions.
---
 emacs/guix-devel.el | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/emacs/guix-devel.el b/emacs/guix-devel.el
index f3ad4b9..170ce1a 100644
--- a/emacs/guix-devel.el
+++ b/emacs/guix-devel.el
@@ -254,6 +254,20 @@ Each rule should have a form (SYMBOL VALUE).  See `put' for details."
                   0)))
     (lisp-indent-specform count state indent-point normal-indent)))
 
+(defun guix-devel-indent-modify-phases-keyword (count)
+  "Return indentation function for 'modify-phases' keywords."
+  (lambda (state indent-point normal-indent)
+    (when (ignore-errors
+            (goto-char (nth 1 state))   ; start of keyword sexp
+            (backward-up-list)
+            (looking-at "(modify-phases\\>"))
+      (lisp-indent-specform count state indent-point normal-indent))))
+
+(defalias 'guix-devel-indent-modify-phases-keyword-1
+  (guix-devel-indent-modify-phases-keyword 1))
+(defalias 'guix-devel-indent-modify-phases-keyword-2
+  (guix-devel-indent-modify-phases-keyword 2))
+
 (guix-devel-scheme-indent
   (bag 0)
   (build-system 0)
@@ -293,7 +307,12 @@ Each rule should have a form (SYMBOL VALUE).  See `put' for details."
   (with-monad 1)
   (with-mutex 1)
   (with-store 1)
-  (wrap-program 1))
+  (wrap-program 1)
+
+  ;; 'modify-phases' keywords:
+  (replace    'guix-devel-indent-modify-phases-keyword-1)
+  (add-after  'guix-devel-indent-modify-phases-keyword-2)
+  (add-before 'guix-devel-indent-modify-phases-keyword-2))
 
 \f
 (defvar guix-devel-keys-map
-- 
2.5.0

Re: [PATCH] emacs: devel: Add indentation rules for 'modify-phases' keywords.

[Ludovic Courtès]

Alex Kost <alezost@gmail.com> skribis:

> This patch will do it.  Of course we can just use:
>
> (put 'replace 'scheme-indent-function 1)
> (put 'add-after 'scheme-indent-function 2)
> (put 'add-before 'scheme-indent-function 2)
>
> But potentially these keywords may also be used outside 'modify-phases'.
>
> So with the attached more complex rules, 'replace', 'add-before' and
> 'add-after' keywords will be indented specially only when they are
> inside 'modify-phases', otherwise they will be indented as usual:

This is perfect.  You have just invented “hygienic indentation.”  :-)

> From 092dbb4460cf140c628eb4aeb4c5fff8f0083b3c Mon Sep 17 00:00:00 2001
> From: Alex Kost <alezost@gmail.com>
> Date: Sat, 17 Oct 2015 19:02:39 +0300
> Subject: [PATCH] emacs: devel: Add indentation rules for 'modify-phases'
>  keywords.
>
> * emacs/guix-devel.el: Add indentation rules for 'modify-phases' keywords.
>   (guix-devel-indent-modify-phases-keyword,
>   guix-devel-indent-modify-phases-keyword-1,
>   guix-devel-indent-modify-phases-keyword-2): New functions.

OK!

Thanks,
Ludo’.

Re: [PATCH] emacs: devel: Add indentation rules for 'modify-phases' keywords.

[Alex Kost]

Ludovic Courtès (2015-10-19 18:44 +0300) wrote:

> Alex Kost <alezost@gmail.com> skribis:
>
>> This patch will do it.  Of course we can just use:
>>
>> (put 'replace 'scheme-indent-function 1)
>> (put 'add-after 'scheme-indent-function 2)
>> (put 'add-before 'scheme-indent-function 2)
>>
>> But potentially these keywords may also be used outside 'modify-phases'.
>>
>> So with the attached more complex rules, 'replace', 'add-before' and
>> 'add-after' keywords will be indented specially only when they are
>> inside 'modify-phases', otherwise they will be indented as usual:
>
> This is perfect.  You have just invented “hygienic indentation.”  :-)

Ha-ha!  Ideally the best would be to make a single indentation rule for
'modify-phases' macro, but I don't know if it's even possible: the
internals of emacs indentation machinery look like a black magic for me.

>> From 092dbb4460cf140c628eb4aeb4c5fff8f0083b3c Mon Sep 17 00:00:00 2001
>> From: Alex Kost <alezost@gmail.com>
>> Date: Sat, 17 Oct 2015 19:02:39 +0300
>> Subject: [PATCH] emacs: devel: Add indentation rules for 'modify-phases'
>>  keywords.
>>
>> * emacs/guix-devel.el: Add indentation rules for 'modify-phases' keywords.
>>   (guix-devel-indent-modify-phases-keyword,
>>   guix-devel-indent-modify-phases-keyword-1,
>>   guix-devel-indent-modify-phases-keyword-2): New functions.
>
> OK!

Pushed, thanks!

-- 
Alex