From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <zsh-users-return-20801-mason-zsh=primenet.com.au@zsh.org>
Received: (qmail 9711 invoked by alias); 21 Oct 2015 03:53:00 -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: 20801
Received: (qmail 11460 invoked from network); 21 Oct 2015 03:52:59 -0000
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on f.primenet.com.au
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.0
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20130820;
        h=x-gm-message-state:from:message-id:date:in-reply-to:comments
         :references:to:subject:mime-version:content-type;
        bh=FNXuVaEF54CkhnX7MLml7/NgJB8c8Xhwr9bt3vAcch8=;
        b=akdOQaeWVC9vLtTa+xuk7E/dSPEso5Hq2P/eW+UvkXecJW6iPESodQfa1rj//eoap1
         5hOqp6SsIdOGeO7ARTokNoW5lG4dAg4NwwKl7LiTACREIU11oh4QxiPTJI98QZqZw7Dc
         4ekkeKhVzIP7o7egLsqzI4w8WFZReokkDQmvoVPrzib/rQbsKJWEhH+eJ2Vq6JbcJ+M9
         bmZeNUSNyr2IWIYp7dTXtVyCe0olGMN7t1HPWXqlpQvqsdmKqEpEvlN0QthuiPn5tKj/
         ItgiLkWj/FE4KQf/2bORMkRX41LyWpNhZc97V2ca48WMVqHloWhhqltCnpG4ZmmgKIj8
         w1EA==
X-Gm-Message-State: ALoCoQkAdzbLBtt5ncxxp2hI+PXCT7B/3DAKwgXkRRnWXqYcpRl6STVcwchvHEqoGK4VKS9TMAxS
X-Received: by 10.60.138.10 with SMTP id qm10mr4419206oeb.42.1445399577492;
        Tue, 20 Oct 2015 20:52:57 -0700 (PDT)
From: Bart Schaefer <schaefer@brasslantern.com>
Message-Id: <151020205254.ZM1906@torch.brasslantern.com>
Date: Tue, 20 Oct 2015 20:52:54 -0700
In-Reply-To: <5626FE9D.9020003@eastlink.ca>
Comments: In reply to Ray Andrews <rayandrews@eastlink.ca>
        "Re: suprise with -=" (Oct 20,  7:55pm)
References: <562483C9.1060602@eastlink.ca> 
	<151019113517.ZM32739@torch.brasslantern.com> 
	<562545DD.5020008@eastlink.ca> 
	<151019172744.ZM558@torch.brasslantern.com> 
	<5626FE9D.9020003@eastlink.ca>
X-Mailer: OpenZMail Classic (0.9.2 24April2005)
To: Ray Andrews <rayandrews@eastlink.ca>, zsh-users@zsh.org
Subject: Re: suprise with -=
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii

On Oct 20,  7:55pm, Ray Andrews wrote:
} Subject: Re: suprise with -=
}
} On 10/19/2015 05:27 PM, Bart Schaefer wrote:
} > The parser doesn't know that "first" is an integer, or even that it's
} > a variable that was previously declared.  This is perfectly legal:
} >
} >      if (( RANDOM % 7 ))
} >      then integer first
} >      else declare first
} >      fi
} >      first+=second
} 
} Then what does 'integer' or 'typset -i' do?

They declare that the internal representation of the variable should be
an integer, so that integer formatting may be applied when the variable
is converted back to a value with $first.

} I can't help but wonder what was going on in the minds of the guys who
} coded the first shells

The first shells didn't have integers or arrays at all.  They had only
strings, and a few (external) programs like "expr" that could interpret
strings of digits as numbers.

Arrays came next and numbers/math last of all, so numbers must conform
to the rules established when the shell was strings-only.  Shells were
never intended to look or behave anything like C (well, except for csh,
but it was only supposed to look like C, not act like it, and it got a
lot of other things wrong).