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From: Bart Schaefer <schaefer@brasslantern.com>
Message-Id: <160125204829.ZM15331@torch.brasslantern.com>
Date: Mon, 25 Jan 2016 20:48:29 -0800
In-Reply-To: <56A6F01E.8030306@inlv.org>
Comments: In reply to Martijn Dekker <martijn@inlv.org>
        "Re: [BUG] quoting within bracket patterns has no effect" (Jan 26,  4:03am)
References: <569C68AB.2010806@inlv.org> 
	<20160118172434.2fb7d5b9@pwslap01u.europe.root.pri> 
	<56A2C6A8.4090108@inlv.org> 
	<160122174949.ZM11794@torch.brasslantern.com> 
	<56A6F01E.8030306@inlv.org>
To: zsh-workers@zsh.org
Subject: Re: [BUG] quoting within bracket patterns has no effect
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On Jan 26,  4:03am, Martijn Dekker wrote:
}
} In normal variable expansion, setting the option SH_WORD_SPLIT causes
} unquoted $var to be equivalent to ${~var} in variable expansion.
} Wouldn't it make sense to have SH_WORD_SPLIT activate pattern characters
} in unquoted variables in range expressions as well?

Look again at my first example from the previous message:

schaefer[691] Src/zsh -f
torch% emulate sh
torch% myrange='a-z'
torch% somevar='c'
torch% case $somevar in
case> ( *[$myrange]* )  echo "$somevar is part of $myrange" ;;
case> esac
c is part of a-z
torch% print $ZSH_PATCHLEVEL
zsh-5.2-103-g69c86cd

What about that is incorrect?  You need $~myrange for "emulate zsh" but
NOT for "emulate sh", unless I'm missing something.

Also it's never been "setopt shwordsplit" that enables patterns in a
parameter expansion, rather it's "setopt globsubst":

schaefer[692] Src/zsh -f
torch% x='c*h'
torch% print $x
c*h
torch% setopt shwordsplit
torch% print $x
c*h
torch% setopt globsubst
torch% print $x
config.h config.modules.sh

What I was pointing out when I said "I'm not sure it's possible to have
it both ways" has ONLY to do with "emulate zsh".  The problem is that
the parsing happens at two different places -- at the time $myrange is
expanded, I don't believe the parameter substitution code knows it's
inside a character set in an active pattern; so there's no way to
temporarily activate globsubst except by explicity doing so.

This may be a case where native zsh is incompatible with POSIX at a
fairly fundamental level; old working zsh scripts are potentially going
to break, and I don't think we can do anything about it unless we want
to tell POSIX to go pound sand.