From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <zsh-users-return-19940-mason-zsh=primenet.com.au@zsh.org>
Received: (qmail 12008 invoked by alias); 1 Mar 2015 19:12:16 -0000
Mailing-List: contact zsh-users-help@zsh.org; run by ezmlm
Precedence: bulk
X-No-Archive: yes
List-Id: Zsh Users List <zsh-users.zsh.org>
List-Post: <mailto:zsh-users@zsh.org>
List-Help: <mailto:zsh-users-help@zsh.org>
X-Seq: 19940
Received: (qmail 25629 invoked from network); 1 Mar 2015 19:12:13 -0000
X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on f.primenet.com.au
X-Spam-Level: 
X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,T_FSL_HELO_BARE_IP_2
	autolearn=ham version=3.3.2
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail;
	t=1425236408; bh=DWc88rNTpy89L0WAhufbJykg1dPe2n6WUu0MFDeiU1g=;
	h=From:To:In-Reply-To:References:Subject:Date;
	b=fCaW5wjBAKBOKbtmEyK3/IMwSkaI2+8solBh/rJXfiyO2QGkyCaWZeIyj+wPUssvX
	 Rxshl9sW+kvuQI6GLMdDScvxHs24cHEQmocwiQRNzOejeLEfcdFGdutIFgcPdHoLKD
	 jVPI1lsEf2+XbFA09sKuSRerV84yPoKcEAQ/MHSY=
From: ZyX <kp-pav@yandex.ru>
To: Bart Schaefer <schaefer@brasslantern.com>,
	zsh Users <zsh-users@zsh.org>
In-Reply-To: <150301104829.ZM16206@torch.brasslantern.com>
References: <54F33934.2070607@eastlink.ca>  <13666281425228233@web7o.yandex.ru> 
	<54F345D3.9010204@eastlink.ca> <150301104829.ZM16206@torch.brasslantern.com>
Subject: Re: grammar triviality with '&&'
MIME-Version: 1.0
Message-Id: <48511425236406@web16g.yandex.ru>
X-Mailer: Yamail [ http://yandex.ru ] 5.0
Date: Sun, 01 Mar 2015 22:00:06 +0300
Content-Transfer-Encoding: 8bit
Content-Type: text/plain; charset=koi8-r

01.03.2015, 21:50, "Bart Schaefer" <schaefer@brasslantern.com>:
> On Mar 1, š9:01am, Ray Andrews wrote:
> }
> } I see, so it's not a 'hard' syntactic issue
>
> Actually it IS a "hard" syntactic issue, in the sense that the grammar
> for all *nix shells [1] both immemorial and standard, formally defines
> newline as equivalent to semicolon.
>
> You can demonstrate that this is the case [2] by:
>
> torch% false && ; echo AND || ; echo OR
> OR
> torch% false ; && echo AND ; || echo OR
> zsh: parse error near `&&'
>
> [1] I don't consider here "shells" written to use the syntax of other
> interpreted languages, such as shells that execute perl or php or
> python statements.
>
> [2] Actually bash throws a syntax error on that "&& ;", but both zsh
> and ksh accept it. šChet?

(Almost) pure POSIX shells like dash, posh and busybox ash also throw syntax error here. This is a direct consequence of how grammar is defined in http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_10_02. Ksh and zsh are far from being POSIX shells.