bug#35646: In SQL mode /- incorrectly starts a comment

bug#35646: In SQL mode /- incorrectly starts a comment

[Michel de Ruiter]

Hi,

I found that both -* and /- incorrectly start a comment in SQL mode.
The -* combination starts a block comment, but cannot be valid SQL
syntax AFAIK. However /- can be and should not start a line comment as
it does now. The simplest example is:
  SELECT 1/-1
It took me a while (https://emacs.stackexchange.com/q/50375) to
understand that this is expected behavior given the
sql-mode-syntax-table.
Of course using whitespace to separate / and -  'solves' the issue.
Someone might want to properly fix this using
syntax-propertize-function (as suggested by Stefan Monnier?,
https://emacs.stackexchange.com/a/50399).

Hope this helps!

Greets, Michel.

bug#35646: In SQL mode /- incorrectly starts a comment

[Kristian Hole]

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Attached is a patch that fixes this by using the following
syntax-propertize-function:

(set (make-local-variable 'syntax-propertize-function)
     (syntax-propertize-rules
      ("\\(/-\\)" (1 "."))
      ("\\(-\\*\\)" (1 "."))))

Adds sql-mode syntax propertize rules to fix comment highlighting

Fixes the issue where -* and /- incorrectly starts comments
in SQL mode Bug(#35646). This is done by adding a
syntax-propertize-function to sql-mode.

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From b6bd0f6f812fdb3200dd240bb8eab5f717ab7c44 Mon Sep 17 00:00:00 2001
From: kahole <kristian@hole.priv.no>
Date: Sun, 27 Oct 2019 21:29:48 +0100
Subject: [PATCH] Adds sql-mode syntax propertize rules to fix comment
 highlighting

Fixes the issue where -* and /- incorrectly starts comments
in SQL mode Bug(#35646). This is done by adding a
syntax-propertize-function to sql-mode.
---
 lisp/progmodes/sql.el | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lisp/progmodes/sql.el b/lisp/progmodes/sql.el
index b17364b08f..645944b34a 100644
--- a/lisp/progmodes/sql.el
+++ b/lisp/progmodes/sql.el
@@ -4253,6 +4253,13 @@ sql-mode
 
   ;; (smie-setup sql-smie-grammar #'sql-smie-rules)
   (set (make-local-variable 'comment-start) "--")
+
+  ;; Propertize rules to not have /- and -* start comments
+  (set (make-local-variable 'syntax-propertize-function)
+       (syntax-propertize-rules
+        ("\\(/-\\)" (1 "."))
+        ("\\(-\\*\\)" (1 "."))))
+
   ;; Make each buffer in sql-mode remember the "current" SQLi buffer.
   (make-local-variable 'sql-buffer)
   ;; Add imenu support for sql-mode.  Note that imenu-generic-expression
-- 
2.18.0

bug#35646: In SQL mode /- incorrectly starts a comment

[Stefan Kangas]

Hi Michael,

Kristian Hole <kristian@hole.priv.no> writes:

> Attached is a patch that fixes this by using the following syntax-propertize-function:
>
> (set (make-local-variable 'syntax-propertize-function)
>      (syntax-propertize-rules
>       ("\\(/-\\)" (1 "."))
>       ("\\(-\\*\\)" (1 "."))))
>
> Adds sql-mode syntax propertize rules to fix comment highlighting
>
> Fixes the issue where -* and /- incorrectly starts comments
> in SQL mode Bug(#35646). This is done by adding a
> syntax-propertize-function to sql-mode.

Could you please take a look also at the below patch?  TIA.

Best regards,
Stefan Kangas

>
> From b6bd0f6f812fdb3200dd240bb8eab5f717ab7c44 Mon Sep 17 00:00:00 2001
> From: kahole <kristian@hole.priv.no>
> Date: Sun, 27 Oct 2019 21:29:48 +0100
> Subject: [PATCH] Adds sql-mode syntax propertize rules to fix comment
>  highlighting
>
> Fixes the issue where -* and /- incorrectly starts comments
> in SQL mode Bug(#35646). This is done by adding a
> syntax-propertize-function to sql-mode.
> ---
>  lisp/progmodes/sql.el | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/lisp/progmodes/sql.el b/lisp/progmodes/sql.el
> index b17364b08f..645944b34a 100644
> --- a/lisp/progmodes/sql.el
> +++ b/lisp/progmodes/sql.el
> @@ -4253,6 +4253,13 @@ sql-mode
>  
>    ;; (smie-setup sql-smie-grammar #'sql-smie-rules)
>    (set (make-local-variable 'comment-start) "--")
> +
> +  ;; Propertize rules to not have /- and -* start comments
> +  (set (make-local-variable 'syntax-propertize-function)
> +       (syntax-propertize-rules
> +        ("\\(/-\\)" (1 "."))
> +        ("\\(-\\*\\)" (1 "."))))
> +
>    ;; Make each buffer in sql-mode remember the "current" SQLi buffer.
>    (make-local-variable 'sql-buffer)
>    ;; Add imenu support for sql-mode.  Note that imenu-generic-expression

bug#35646: In SQL mode /- incorrectly starts a comment

[Lars Ingebrigtsen]

Kristian Hole <kristian@hole.priv.no> writes:

> Attached is a patch that fixes this by using the following
> syntax-propertize-function:
>
> (set (make-local-variable 'syntax-propertize-function)
>      (syntax-propertize-rules
>       ("\\(/-\\)" (1 "."))
>       ("\\(-\\*\\)" (1 "."))))
>
> Adds sql-mode syntax propertize rules to fix comment highlighting
>
> Fixes the issue where -* and /- incorrectly starts comments
> in SQL mode Bug(#35646). This is done by adding a
> syntax-propertize-function to sql-mode.

Thanks; I've now adapted your code to work in Emacs 28.1 -- some other
changes had been made in this area that made your patch no longer apply.

I also cleaned up (and simplified) the previous patch at the same time.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no