Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c > #20613

Re: Operator precedence.

From Ike Naar <ike@sverige.freeshell.org>
Newsgroups comp.lang.c
Subject Re: Operator precedence.
Date 2012-05-11 19:20 +0000
Organization A noiseless patient Spider
Message-ID <slrn3vfsjqqpkb.kv6.ike@sverige.freeshell.org> (permalink)
References (3 earlier) <joh5cv$bdv$1@dont-email.me> <joj40b$e1t$1@dont-email.me> <jojc23$m4$1@dont-email.me> <4FAD3E13.7000804@verizon.net> <jojkr0$r88$1@dont-email.me>

Show all headers | View raw

On 2012-05-11, BartC <bc@freeuk.com> wrote:
> "James Kuyper" <jameskuyper@verizon.net> wrote in message 
> news:4FAD3E13.7000804@verizon.net...
>> On 05/11/2012 11:42 AM, BartC wrote:
>>> in your examples. The precedence table in K&R2 suggests that a series of
>>> unary ops such as op1 op2 A op3 op4 should be calculated as op1(op2((A 
>>> op4)
>>> op3)) (with 3 and 4 interchanged). They are confusing.
>>
>> That's a rather confusing statement. Why did you write "with 3 and 4
>> interchanged" rather than simply interchanging 3 and 4?
>
> Because you might have thought it a typo otherwise. K&R says unary ops 
> associate from  right to left. So op4 first.

Right-to-left associativity only holds for the prefix unary operators.
Postfix unary operators associate from left to right.
In your example,

  op1 op2 A op4 op4

should be calculated as

  op1 (op2 ((A op4) op3))

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Operator precedence. somenath <somenathpal@gmail.com> - 2012-05-06 20:10 -0700
  Re: Operator precedence. somenath <somenathpal@gmail.com> - 2012-05-06 20:23 -0700
  Re: Operator precedence. James Kuyper <jameskuyper@verizon.net> - 2012-05-06 23:57 -0400
  Re: Operator precedence. Kaz Kylheku <kaz@kylheku.com> - 2012-05-07 03:59 +0000
  Re: Operator precedence. pete <pfiland@mindspring.com> - 2012-05-07 05:48 -0400
    Re: Operator precedence. James Kuyper <jameskuyper@verizon.net> - 2012-05-07 07:52 -0400
      Re: Operator precedence. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-07 13:18 +0100
        Re: Operator precedence. James Kuyper <jameskuyper@verizon.net> - 2012-05-07 09:08 -0400
          Re: Operator precedence. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-07 14:36 +0100
            Re: Operator precedence. James Kuyper <jameskuyper@verizon.net> - 2012-05-07 13:29 -0400
      Re: Operator precedence. pete <pfiland@mindspring.com> - 2012-05-07 11:24 -0400
  Re: Operator precedence. "BartC" <bc@freeuk.com> - 2012-05-07 16:35 +0100
    Re: Operator precedence. jgk@panix.com (Joe keane) - 2012-05-10 19:05 +0000
      Re: Operator precedence. "BartC" <bc@freeuk.com> - 2012-05-10 20:35 +0100
        Re: Operator precedence. James Kuyper <jameskuyper@verizon.net> - 2012-05-11 09:25 -0400
          Re: Operator precedence. "BartC" <bc@freeuk.com> - 2012-05-11 16:42 +0100
            Re: Operator precedence. James Kuyper <jameskuyper@verizon.net> - 2012-05-11 12:28 -0400
              Re: Operator precedence. "BartC" <bc@freeuk.com> - 2012-05-11 18:42 +0100
                Re: Operator precedence. James Kuyper <jameskuyper@verizon.net> - 2012-05-11 15:18 -0400
                Re: Operator precedence. "BartC" <bc@freeuk.com> - 2012-05-11 22:52 +0100
                Re: Operator precedence. James Kuyper <jameskuyper@verizon.net> - 2012-05-11 18:39 -0400
                Re: Operator precedence. Ike Naar <ike@sverige.freeshell.org> - 2012-05-11 19:20 +0000
                Re: Operator precedence. Ike Naar <ike@sverige.freeshell.org> - 2012-05-11 19:28 +0000
                Re: Operator precedence. "BartC" <bc@freeuk.com> - 2012-05-11 22:28 +0100
                Re: Operator precedence. Ike Naar <ike@sverige.freeshell.org> - 2012-05-11 21:45 +0000
              Re: Operator precedence. Keith Thompson <kst-u@mib.org> - 2012-05-12 12:11 -0700
            Re: Operator precedence. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-11 17:37 +0100
        Re: Operator precedence. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-11 16:24 +0100
          Re: Operator precedence. "BartC" <bc@freeuk.com> - 2012-05-11 20:14 +0100
            Re: Operator precedence. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-11 20:56 +0100
              Re: Operator precedence. "BartC" <bc@freeuk.com> - 2012-05-11 22:21 +0100
                Re: Operator precedence. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-12 00:05 +0100
          Re: Operator precedence. jgk@panix.com (Joe keane) - 2012-05-11 22:46 +0000
            Re: Operator precedence. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-12 00:17 +0100
              Re: Operator precedence. jgk@panix.com (Joe keane) - 2012-05-12 19:35 +0000
                Re: Operator precedence. "BartC" <bc@freeuk.com> - 2012-05-12 22:39 +0100
            Re: Operator precedence. Keith Thompson <kst-u@mib.org> - 2012-05-12 16:07 -0700
              Re: Operator precedence. jgk@panix.com (Joe keane) - 2012-05-13 19:08 +0000
                Re: Operator precedence. Keith Thompson <kst-u@mib.org> - 2012-05-13 13:17 -0700
                Re: Operator precedence. jgk@panix.com (Joe keane) - 2012-05-14 21:06 +0000
                Re: Operator precedence. Keith Thompson <kst-u@mib.org> - 2012-05-14 20:42 -0700
                Re: Operator precedence. Kaz Kylheku <kaz@kylheku.com> - 2012-05-13 23:20 +0000
      Re: Operator precedence. Keith Thompson <kst-u@mib.org> - 2012-05-10 15:24 -0700

csiph-web