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From: Bart Schaefer <schaefer@brasslantern.com>
To: Zsh Users <zsh-users@zsh.org>
Subject: Re: for loop question
Date: Sun, 2 Nov 2014 14:57:22 -0800	[thread overview]
Message-ID: <CAH+w=7b55P0QdPaeA_dpmPbGaYERcm5nFXthFxN_5YpvFRDGyw@mail.gmail.com> (raw)
In-Reply-To: <5456B3E6.4040907@eastlink.ca>

[-- Attachment #1: Type: text/plain, Size: 716 bytes --]

On Nov 2, 2014 2:42 PM, "Ray Andrews" <rayandrews@eastlink.ca> wrote:
>
> But it does show that 'for ((' CAN stop and digest  ' [ -n "$TLC[i]" ] '
if it wants too,
> it just has to make it obscenely difficult. Why can't the truth test of a
command just be taken
> as 'arithmetic' plain and simple?

It's a matter of order-of-evaluation and contextual tokenization.  Once the
parser encounters "for ((" it stops looking for ordinary shell command
tokens and starts looking for math tokens; a word like "test" in that
context is a numeric variable name, not a command name, and "[" has another
meaning as well.  But "$" introduces an expansion in either context, so
$(...) switches back into the regular parsing mode.

  reply	other threads:[~2014-11-02 22:57 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-02 20:47 Ray Andrews
2014-11-02 21:00 ` Bart Schaefer
     [not found] ` <CAH+w=7aWS0xyS4CXRJBphDjesfUFQOsyJRMaG3RZRxmuj7xkOg__20885.3257158355$1414962125$gmane$org@mail.gmail.com>
2014-11-02 21:37   ` Stephane Chazelas
2014-11-02 22:44     ` Ray Andrews
2014-11-02 22:57       ` Bart Schaefer [this message]
2014-11-02 23:24       ` Oliver Kiddle
2014-11-03  0:07         ` Ray Andrews
2014-11-03  1:53     ` Mikael Magnusson
2014-11-03  2:22       ` Ray Andrews
2014-11-03  9:22         ` Mikael Magnusson
2014-11-03 17:26           ` Ray Andrews
2014-11-04  1:56     ` Han Pingtian
2014-11-04  2:29       ` Han Pingtian
2014-11-04  2:43       ` Bart Schaefer
2014-11-04  4:51         ` Han Pingtian
2014-11-04  6:37         ` Ray Andrews
2014-11-04  7:13           ` Bart Schaefer
2014-11-04 18:00             ` Ray Andrews
     [not found]       ` <141103184338.ZM32221__48957.5251042426$1415069142$gmane$org@torch.brasslantern.com>
2014-11-04  7:08         ` Stephane Chazelas

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