From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <zsh-workers-return-40928-mason-zsh=primenet.com.au@zsh.org>
Received: (qmail 28939 invoked by alias); 2 Apr 2017 18:52:03 -0000
Mailing-List: contact zsh-workers-help@zsh.org; run by ezmlm
Precedence: bulk
X-No-Archive: yes
List-Id: Zsh Workers List <zsh-workers.zsh.org>
List-Post: <mailto:zsh-workers@zsh.org>
List-Help: <mailto:zsh-workers-help@zsh.org>
X-Seq: 40928
Received: (qmail 23134 invoked from network); 2 Apr 2017 18:52:03 -0000
X-Qmail-Scanner-Diagnostics: from mail-vk0-f43.google.com by f.primenet.com.au (envelope-from <schaefer@brasslantern.com>, uid 7791) with qmail-scanner-2.11 
 (clamdscan: 0.99.2/21882. spamassassin: 3.4.1.  
 Clear:RC:0(209.85.213.43):SA:0(-2.8/5.0):. 
 Processed in 1.088329 secs); 02 Apr 2017 18:52:03 -0000
X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on f.primenet.com.au
X-Spam-Level: 
X-Spam-Status: No, score=-2.8 required=5.0 tests=RCVD_IN_DNSWL_NONE,
	RCVD_IN_MSPIKE_H2,SPF_PASS,T_DKIM_INVALID autolearn=unavailable
	autolearn_force=no version=3.4.1
X-Envelope-From: schaefer@brasslantern.com
X-Qmail-Scanner-Mime-Attachments: |
X-Qmail-Scanner-Zip-Files: |
Received-SPF: pass (ns1.primenet.com.au: SPF record at _netblocks.google.com designates 209.85.213.43 as permitted sender)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=brasslantern-com.20150623.gappssmtp.com; s=20150623;
        h=from:message-id:date:to:subject:mime-version;
        bh=UHz/8qCrSVLX9AMZZwfyp/iH88A3230BfKLSAKvtjU8=;
        b=o/1cTGvNKhIOpa2EOpA1+wMeWbXwOIQTbDQx1cxEpvIvzJfqqopb7YNAzyW96HejUY
         Qwr3r2dFQz+orJWPXNuste0Q3VE78wjmgfoyEB68B7NTZlb7d0uuQ2OGAduvafHMu5FD
         RHEXDpszImRV94Pl70TBBtydmpmLq7gzaY9GcC7mHizQGoWP1iAxNHGIpkQgB/xVtdSn
         3h3eX9QRP64I3KjCiBCKMNC2taDqu9kErCKhHniOLs4EGdu5PeCjHm/3vG2x3hA6XRid
         t6zppoBW/4lKZMAUBUegth4FP7+3Me+DK9mzA1qC4jy205yz8UBk1t6C3tg58RETykYW
         i67g==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20161025;
        h=x-gm-message-state:from:message-id:date:to:subject:mime-version;
        bh=UHz/8qCrSVLX9AMZZwfyp/iH88A3230BfKLSAKvtjU8=;
        b=SAySS9LGrVNAlbP9xmZmdppiVcDjA7mx5d1BWGF8WBMDSpqS1zLMT9eO/TiJyho8H/
         qxAVg3f1setHT7DUtwA7VtXwso4LRWEnw/MJnzhwCUSl9Yl7QL9zpHyt3oWT5lWSMy9V
         RYWUocyslYPxPyVr+oNVW5isILeqhC8uPknk2d+rkI93u5JT9RenkkQmep15vRQoZWvy
         Zp/KB/s3fs8LJ5SLApiIVwZJx+oSX8wRdME0q+H5DC/81pstMUWAgbzfGY5n71cKChuy
         xU3SiAVtdzhmz9eefZWqX2YORb9uayN2izr1Ro2CcK0XqSskRr1yqcDJzLNuXkEK5qWC
         L72Q==
X-Gm-Message-State: AFeK/H0DB07Wl5EjzSzq8jqRs+EqOkcH86rGl/Hk0fh98f00t+kq/N8kN4jLsD7p7FPJqw==
X-Received: by 10.31.15.82 with SMTP id 79mr5722933vkp.156.1491159113803;
        Sun, 02 Apr 2017 11:51:53 -0700 (PDT)
From: Bart Schaefer <schaefer@brasslantern.com>
Message-Id: <170402115156.ZM27355@torch.brasslantern.com>
Date: Sun, 2 Apr 2017 11:51:56 -0700
X-Mailer: OpenZMail Classic (0.9.2 24April2005)
To: zsh-workers@zsh.org
Subject: Can't call multi-arg math function from array subscript
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii

Single-argument functions are OK:

% string='abcde'
% onearg() { return $1 }
% functions -M onearg
% print ${string[1,onearg(3)]
abc

Add another argument and strange things start happening:

% twoarg() { return $(( $2 - $1 )) }
% functions -M twoarg
% print ${string[1,twoarg(1,4)]}
twoarg: bad math expression: operand expected at end of string
twoarg: bad math expression: operand expected at end of string

Why two error messages?

I assume the comma is messing things up; let's try it like this:

% print ${string[1,$(( twoarg(1,4) ))]}
zsh: parse error
zsh: parse error

Just to confirm:

% print ${string[1,$(( onearg(4) ))]} 
abcd