Re: [9front] Fwd: new rc parser

[Stanley Lieber <sl@stanleylieber.com>]

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