Re: Quoting and ${(e)param} (was Re: destructive list-expand)

["Bart Schaefer" <schaefer@xxxxxxxxxxxxxxxxxxxxxxx>]

(Hello, it's nearly 3am here and I'm waiting for my Windows machine to
repair its disk ... if I leave it alone I can't answer the dialogs that it
throws up periodically, and not answering causes it to lock up and have to
be reset, which of course only makes matters worse ...)

On May 17, 11:03am, Sven Wischnowsky wrote:
}
} Actually, the current state really isn't that far away from the right
} thing. The (e) flag should make only the $-expansions from the value be
} done on the result. Because of that parsing the string as in double
} quotes is the right thing. Using parse_subst_string() or adding the
} `parsestr()-as-if-not-in-quotes' Bart suggested would make glob pattern
} be expanded, too.

OK, that's obviously not ideal ...

} So the easiest solution would be to just make paramsubst() always
} tokenize the pattern strings, not only if it knows that the parameter
} expansion is in quotes. I was fearing that this might result in some
} quoting problems (having to double backslashes or some such), but it
} seems to work, including handling of parameter expansions inside
} patterns.

Yes, it's pretty obvious that it should work:  parse_subst_str() does
an untokenize() before it lexes the string, so it won't matter if the
string is or is not already tokenized.  All that your patch is doing is
removing an optimization.

Consequently I think it would be OK to include it (possibly with the #if
replaced by an explanatory comment).  It'll slow down expansion of un-
quoted parameters slightly in the name of correctness, a tradeoff I made
several times in my subscript-parsing changes.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net