Fwd: new rc parser

Fwd: new rc parser

[Stanley Lieber]

-------- Original Message --------
From: Russ Cox <rsc@swtch.com>
Sent: May 4, 2020 11:57:22 PM EDT
To: plan9port-dev <plan9port-dev@googlegroups.com>
Subject: new rc parser

Hi all,

As an experiment, I have pushed to plan9port a new rc parser
<https://github.com/9fans/plan9port/commit/47d4646eebac34c0b94951cfcf1b81ed2ca513e1>
that resolves two long-time nagging issues:

1. Equal signs (=) are now allowed unquoted
<https://github.com/9fans/plan9port/commit/ff74f7cdda7b08da6fe7c8bbcca990305fd6b547>
in command line arguments.

2. Free carats are now inserted
<https://github.com/9fans/plan9port/commit/7d6a248f2c68d70f58387afc69e73e695c3d940c>
any time two word expressions are next to each other with no spaces, not
just most of the time. For example, the Plan 9 printfont script contains a
bug of the form:

    x=$x'abc'`{def}'ghi'

The bug is that an explicit carat is needed after the }. No longer.

I tested the change by checking every rc script I could find against the
old and new parser; the printfont script mentioned above was the only
affected script (and it's not in plan9port anyway).

You can compare the parser output on any particular script using:

    diff <{rc -Y -D script} <{rc -D script}

If you run into any problems, the old parser is still available using "rc
-Y", but please file an issue so we can fix the new parser.

Best,
Russ

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Re: [9front] Fwd: new rc parser

[ori]

> -------- Original Message --------
> From: Russ Cox <rsc@swtch.com>
> Sent: May 4, 2020 11:57:22 PM EDT
> To: plan9port-dev <plan9port-dev@googlegroups.com>
> Subject: new rc parser
> 
> Hi all,
> 
> As an experiment, I have pushed to plan9port a new rc parser
> <https://github.com/9fans/plan9port/commit/47d4646eebac34c0b94951cfcf1b81ed2ca513e1>
> that resolves two long-time nagging issues:
> 
> 1. Equal signs (=) are now allowed unquoted
> <https://github.com/9fans/plan9port/commit/ff74f7cdda7b08da6fe7c8bbcca990305fd6b547>
> in command line arguments.
> 
> 2. Free carats are now inserted
> <https://github.com/9fans/plan9port/commit/7d6a248f2c68d70f58387afc69e73e695c3d940c>
> any time two word expressions are next to each other with no spaces, not
> just most of the time. For example, the Plan 9 printfont script contains a
> bug of the form:
> 
>     x=$x'abc'`{def}'ghi'
> 
> The bug is that an explicit carat is needed after the }. No longer.
> 
> I tested the change by checking every rc script I could find against the
> old and new parser; the printfont script mentioned above was the only
> affected script (and it's not in plan9port anyway).
> 
> You can compare the parser output on any particular script using:
> 
>     diff <{rc -Y -D script} <{rc -D script}
> 
> If you run into any problems, the old parser is still available using "rc
> -Y", but please file an issue so we can fix the new parser.
> 
> Best,
> Russ
> 

I think it's fixing something that wasn't broken -- but I dont' hate it.
The changes to free carets make sense to me, and the bare '=' in words
doesn't hurt.

Looking at the recent p9p commits, there seems to be a burst of activity,
and there may be a couple of others that we may also want to cherry pick
in. I haven't looked too hard yet, but these look like they make sense:

	5c06214952017d03f5e36bd1fbf25c1969922d80
		venti/buildindex: fix hang on large indexes
	d2df5d6cbd345e101732fe7d22bb5b3baa5fb61a
		acme: fix crash in X |cat with multiple windows

Re: [9front] Fwd: new rc parser

[kvik]

> The changes to free carets make sense to me, and the bare '='
> in words doesn't hurt.

Both are nice improvements.  I agree that we should watch
porters fly this for a while before ingestion.

Re: [9front] Fwd: new rc parser

[Stanley Lieber]

On May 5, 2020 1:49:36 AM EDT, ori@eigenstate.org wrote:
>> -------- Original Message --------
>> From: Russ Cox <rsc@swtch.com>
>> Sent: May 4, 2020 11:57:22 PM EDT
>> To: plan9port-dev <plan9port-dev@googlegroups.com>
>> Subject: new rc parser
>> 
>> Hi all,
>> 
>> As an experiment, I have pushed to plan9port a new rc parser
>> <https://github.com/9fans/plan9port/commit/47d4646eebac34c0b94951cfcf1b81ed2ca513e1>
>> that resolves two long-time nagging issues:
>> 
>> 1. Equal signs (=) are now allowed unquoted
>> <https://github.com/9fans/plan9port/commit/ff74f7cdda7b08da6fe7c8bbcca990305fd6b547>
>> in command line arguments.
>> 
>> 2. Free carats are now inserted
>> <https://github.com/9fans/plan9port/commit/7d6a248f2c68d70f58387afc69e73e695c3d940c>
>> any time two word expressions are next to each other with no spaces, not
>> just most of the time. For example, the Plan 9 printfont script contains a
>> bug of the form:
>> 
>>     x=$x'abc'`{def}'ghi'
>> 
>> The bug is that an explicit carat is needed after the }. No longer.
>> 
>> I tested the change by checking every rc script I could find against the
>> old and new parser; the printfont script mentioned above was the only
>> affected script (and it's not in plan9port anyway).
>> 
>> You can compare the parser output on any particular script using:
>> 
>>     diff <{rc -Y -D script} <{rc -D script}
>> 
>> If you run into any problems, the old parser is still available using "rc
>> -Y", but please file an issue so we can fix the new parser.
>> 
>> Best,
>> Russ
>> 
>
>I think it's fixing something that wasn't broken -- but I dont' hate it.
>The changes to free carets make sense to me, and the bare '=' in words
>doesn't hurt.
>
>Looking at the recent p9p commits, there seems to be a burst of activity,
>and there may be a couple of others that we may also want to cherry pick
>in. I haven't looked too hard yet, but these look like they make sense:
>
>	5c06214952017d03f5e36bd1fbf25c1969922d80
>		venti/buildindex: fix hang on large indexes
>	d2df5d6cbd345e101732fe7d22bb5b3baa5fb61a
>		acme: fix crash in X |cat with multiple windows
>

iirc, aiju suggested these exact changes on irc some time ago. at the time i objected mainly because i didn't like the idea of feature-incompatible rc. if rsc is pushing this to p9p, it will probably end up in 9legaacy, etc. it's a bold new day as we leave labs rc behind.

sl

Re: [9front] Fwd: new rc parser

[hiro]

my memory of 9legacy is fading

Re: [9front] Fwd: new rc parser

[Stanley Lieber]

On May 5, 2020 11:00:06 AM EDT, hiro <23hiro@gmail.com> wrote:
>my memory of 9legacy is fading

don't mirror the artwork.

sl

Re: [9front] Fwd: new rc parser

[jamos]

I noticed that -DVAR=smthing (to add defines for the compiler) works in 
mk scripts but not on the command line, where it has to be escaped, 
because of the equal sign. The suggested change might make mk and rc 
work the same.

On 2020-05-05 16:00, kvik@a-b.xyz wrote:

>> The changes to free carets make sense to me, and the bare '='
>> in words doesn't hurt.
> 
> Both are nice improvements.  I agree that we should watch
> porters fly this for a while before ingestion.