[9fans] Sam commands in acme

[9fans] Sam commands in acme

[hugo rivera]

Hi,
I am trying to select all c comments from within a file using acme,
but I am unable to do it properly. The command x/\/\*.*\*\// is the
closest I could get, but it doesn't work with comments that span over
more than one line. This raises a question for me: somewhere, I cannot
recall where, I read that commands in sam (and therefore acme) aren't
line oriented but selection oriented, so, shouldn't '.*' match newline
characters also? why it doesn't? I expected '.*' to work with newline
characters since it works for spaces and tabs, and the three of them
are white space, among others.
And finally, what command I should use to select c comments without
regard if they are several lines long or just one?
Saludos
--
Hugo

Re: [9fans] Sam commands in acme

[yy]

2009/6/26 hugo rivera <uair00@gmail.com>:
> Hi,
> I am trying to select all c comments from within a file using acme,
> but I am unable to do it properly. The command x/\/\*.*\*\// is the
> closest I could get, but it doesn't work with comments that span over
> more than one line. This raises a question for me: somewhere, I cannot
> recall where, I read that commands in sam (and therefore acme) aren't
> line oriented but selection oriented, so, shouldn't '.*' match newline
> characters also? why it doesn't? I expected '.*' to work with newline
> characters since it works for spaces and tabs, and the three of them
> are white space, among others.

You could use (\n|.) to match any character including newlines
(regex(6) says that a new line is not cosidered "any character", and
as a matter of fact, \n is part of the sam language, not of regex
itself). However, since the longest possible regex will be matched,
then you will also match the end of the comment, so for example in:
/* comment 1 */
bar
/* comment 2 */
you will match everything, I don't think that is what you want.

> And finally, what command I should use to select c comments without
> regard if they are several lines long or just one?

Edit ,x/\/\*/.,/\*\//c/COMMENT/

The possibility of modifying the dot is powerful. Many times it is
much easier than finding an huge regex.

> Saludos
> --
> Hugo
>
>

Un saludo,


--
- yiyus || JGL .

Re: [9fans] Sam commands in acme

[hugo rivera]

I tested the command you suggested (,x/\/\*/.,/\*\//) and it works as
I wanted, thanks. But there's something I still don't understand and
is the meaning of that comma in there. As far as I know, the comma is
a  mark that delimits the addresses that acme understands, but I do
not know how a comma is interpreted inside a regexp. I'd really
appreciate if you could clarify this matter to me.

2009/6/26 yy <yiyu.jgl@gmail.com>:
> 2009/6/26 hugo rivera <uair00@gmail.com>:
>> Hi,
>> I am trying to select all c comments from within a file using acme,
>> but I am unable to do it properly. The command x/\/\*.*\*\// is the
>> closest I could get, but it doesn't work with comments that span over
>> more than one line. This raises a question for me: somewhere, I cannot
>> recall where, I read that commands in sam (and therefore acme) aren't
>> line oriented but selection oriented, so, shouldn't '.*' match newline
>> characters also? why it doesn't? I expected '.*' to work with newline
>> characters since it works for spaces and tabs, and the three of them
>> are white space, among others.
>
> You could use (\n|.) to match any character including newlines
> (regex(6) says that a new line is not cosidered "any character", and
> as a matter of fact, \n is part of the sam language, not of regex
> itself). However, since the longest possible regex will be matched,
> then you will also match the end of the comment, so for example in:
> /* comment 1 */
> bar
> /* comment 2 */
> you will match everything, I don't think that is what you want.
>
>> And finally, what command I should use to select c comments without
>> regard if they are several lines long or just one?
>
> Edit ,x/\/\*/.,/\*\//c/COMMENT/
>
> The possibility of modifying the dot is powerful. Many times it is
> much easier than finding an huge regex.
>
>> Saludos
>> --
>> Hugo
>>
>>
>
> Un saludo,
>
>
> --
> - yiyus || JGL .
>
>



--
Hugo

Re: [9fans] Sam commands in acme

[Rudolf Sykora]

2009/6/26 hugo rivera <uair00@gmail.com>:
> I tested the command you suggested (,x/\/\*/.,/\*\//) and it works as
> I wanted, thanks. But there's something I still don't understand and
> is the meaning of that comma in there. As far as I know, the comma is
> a  mark that delimits the addresses that acme understands, but I do
> not know how a comma is interpreted inside a regexp. I'd really
> appreciate if you could clarify this matter to me.

I think, the comma is not in a regexp. The 'x' command syntax is
x/regexp/command
and the comma is a part of the command: choose the area from the dot
(included) to the '*/'

Ruda

Re: [9fans] Sam commands in acme

[hugo rivera]

Yes, you are right. Now I understand it, I missed the / after \*, so I
was thinking that the comma was inside the regexp.
Thanks a lot :-)

2009/6/26 Rudolf Sykora <rudolf.sykora@gmail.com>:
> 2009/6/26 hugo rivera <uair00@gmail.com>:
>> I tested the command you suggested (,x/\/\*/.,/\*\//) and it works as
>> I wanted, thanks. But there's something I still don't understand and
>> is the meaning of that comma in there. As far as I know, the comma is
>> a  mark that delimits the addresses that acme understands, but I do
>> not know how a comma is interpreted inside a regexp. I'd really
>> appreciate if you could clarify this matter to me.
>
> I think, the comma is not in a regexp. The 'x' command syntax is
> x/regexp/command
> and the comma is a part of the command: choose the area from the dot
> (included) to the '*/'
>
> Ruda
>
>



--
Hugo

Re: [9fans] Sam commands in acme

[roger peppe]

you need (.|\n) instead of .

sam originally used @ as a "match everything" character
but it was removed, presumably because it was rarely used.

to match C comments, you need something like this:

x/\/\*([^*]|\*[^\/]|[^*\/]|\n)*\*\//

2009/6/26 hugo rivera <uair00@gmail.com>:
> Hi,
> I am trying to select all c comments from within a file using acme,
> but I am unable to do it properly. The command x/\/\*.*\*\// is the
> closest I could get, but it doesn't work with comments that span over
> more than one line. This raises a question for me: somewhere, I cannot
> recall where, I read that commands in sam (and therefore acme) aren't
> line oriented but selection oriented, so, shouldn't '.*' match newline
> characters also? why it doesn't? I expected '.*' to work with newline
> characters since it works for spaces and tabs, and the three of them
> are white space, among others.
> And finally, what command I should use to select c comments without
> regard if they are several lines long or just one?
> Saludos
> --
> Hugo
>
>

Re: [9fans] Sam commands in acme

[J.R. Mauro]

On Fri, Jun 26, 2009 at 6:57 AM, roger peppe<rogpeppe@gmail.com> wrote:
> you need (.|\n) instead of .
>
> sam originally used @ as a "match everything" character
> but it was removed, presumably because it was rarely used.

That's a stupid reason to remove a good feature. By that token, maybe
we should remove structural regular expressions since they're "rarely
used" and just go back to using ed.

Do you know if anyone preserved this feature and could send me the patch?

>
> to match C comments, you need something like this:
>
> x/\/\*([^*]|\*[^\/]|[^*\/]|\n)*\*\//
>
> 2009/6/26 hugo rivera <uair00@gmail.com>:
>> Hi,
>> I am trying to select all c comments from within a file using acme,
>> but I am unable to do it properly. The command x/\/\*.*\*\// is the
>> closest I could get, but it doesn't work with comments that span over
>> more than one line. This raises a question for me: somewhere, I cannot
>> recall where, I read that commands in sam (and therefore acme) aren't
>> line oriented but selection oriented, so, shouldn't '.*' match newline
>> characters also? why it doesn't? I expected '.*' to work with newline
>> characters since it works for spaces and tabs, and the three of them
>> are white space, among others.
>> And finally, what command I should use to select c comments without
>> regard if they are several lines long or just one?
>> Saludos
>> --
>> Hugo
>>
>>
>
>

Re: [9fans] Sam commands in acme

[Rob Pike]

On Sat, Jun 27, 2009 at 11:17 AM, J.R. Mauro<jrm8005@gmail.com> wrote:
> On Fri, Jun 26, 2009 at 6:57 AM, roger peppe<rogpeppe@gmail.com> wrote:
>> you need (.|\n) instead of .
>>
>> sam originally used @ as a "match everything" character
>> but it was removed, presumably because it was rarely used.
>
> That's a stupid reason to remove a good feature. By that token, maybe
> we should remove structural regular expressions since they're "rarely
> used" and just go back to using ed.

Indeed, but it's an excellent reason to remove a bad feature.  @ was a
bad feature. It was hard to use well because @* or @+ would consume
the whole file.  Plus it was barely a feature, just a convenience
entirely equivalent to (.|\n), which, by the way, you almost never
see.

It went in when we didn't yet know how the all-one-string model of sam
would turn out.  It turned out just fine and didn't need the @
feature, so out it went.  After several years went by without my using
it once, while @ simultaneously became useful as a real character so
annoying as a metacharacter, out it went.

Deletion is the greatest tool of software design.

-rob

Re: [9fans] Sam commands in acme

[J.R. Mauro]

On Sat, Jun 27, 2009 at 3:20 PM, Rob Pike<robpike@gmail.com> wrote:
>
> Indeed, but it's an excellent reason to remove a bad feature.  @ was a
> bad feature. It was hard to use well because @* or @+ would consume
> the whole file.

Your structural regex paper gripes about . and * not consuming
newlines. Apparently it didn't work in practice as you say, but have
you thought about a different way that might work since? Changing the
delimiter based on context would seem like a good, though heavyweight
and probably harder-to-understand approach.

>
> Deletion is the greatest tool of software design.
>

Quite, though this one in particular seems much less out of place in
sam compared to * despite its glaring faults.

Re: [9fans] Sam commands in acme

[roger peppe]

2009/6/27 Rob Pike <robpike@gmail.com>:
> Deletion is the greatest tool of software design.

yes, i always get great pleasure from deleting code.

unfortunately the overall line count almost always seems to trend
upwards regardless of the amount of code deleted.

Re: [9fans] Sam commands in acme

[erik quanstrom]

> unfortunately the overall line count almost always seems to trend
> upwards regardless of the amount of code deleted.

we are unwitting wack-a-mole players.

- erik