Bug #9983 Updated: Operator Precedence Clarification/Additions
| From: | yohgaki at dd dot iij4u dot or dot jp | Date: | Wed, 27 Jun 2001 07:37:24 +0000 |
| Subject: | Bug #9983 Updated: Operator Precedence Clarification/Additions | ||
| Groups: | php.dev | ||
| Request: | Send a blank email to php-dev+get-58162@lists.php.net to get a copy of this message | ||
ID: 9983
User Update by: yohgaki@dd.iij4u.or.jp
Status: Open
Bug Type: Documentation problem
Operating system: Linux/W2K
PHP Version: 4.0.4pl1
Description: Operator Precedence Clarification/Additions
This is a suggestion for improving the manual.
(I don't mind at all if you close this :)
Reference is for PHP programmers, so I think precidence section is better to include more operators.
For example, it does not matter if unary '+/-', array '[]', member selecter
'->', etc are treated by parser or internal function for programmers. Programmers
don't cares about it when they are programming in some language, right?
Important thing for programmers is the precedence itself in some expression.
How about add more description for precedence just like other books or references for programming
languages?
I feel precedence is not described fully in current manual and it's worth the effort.
----Another Releated Suggestion----
I see confusion occasionally in mail lists for variables in string. Since parser behaives
differently when parsing variables in strings.
This may be one of the reason why '->','[]',unary'+/-' is not in
the precedence section. They wouldn't work when they are in a string. (Some of them work with
newer PHP, not recommended(?) syntax, though)
How about describe these differences in the manual also?
Previous Comments:
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[2001-06-27 01:49:36] danbeck@php.net
Changing description to be more meaningful for someone who wants to tackle this.
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[2001-03-26 05:10:50] yohgaki@dd.iij4u.or.jp
I read precedence list again. There is "." operator listed and has higher precedence than
"?:" operator. So PHP is working as expected. I didn't see "." It was hard
to see on my browser. Thanks.
Anyway, I have suggestion for the manual page, so I changed status to open as "Documentation
Problem".
I think the manual page better to have relevant language constructs in the precedence list even if
it is not a actually a operator in PHP. (Such as "()", "{}", "::",
"->", unary "-","+". It seems these are not a operator in PHP,
since they are not listed. Not sure though.) Only "()" is described in the section. All of
them affects how expressions are evaluated in script and I think precedence for these is important
as operator precedence because programmers want expressions are evaluated as expected.
How about change the section title from "Operator Precedence" to "Precedence"?
Then documentation can include anything that can affects expression and still have consistency with
section title.
It also would be nice to have a little explaination for each operator in the precedence list. Since
it is ambigous if listed operator is unary or binary. For example, unary "-" should have
higher precedence than binary "-". It would be obvious for most users, but it may be
usuful for someone.
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[2001-03-26 03:46:52] sniper@php.net
Please read this manual page:
http://www.php.net/manual/en/language.operators.precedence.php
--Jani
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[2001-03-26 00:17:05] yohgaki@dd.iij4u.or.jp
Following code, needs "()" to get expected value.
$bar = true;
$str = "TEST". ($bar ? 'true' : 'false') ."TEST";
Without "(" and ")", only "true" will be in $str.
(PHP4.0.4pl1/Apache DSO/Linux, PHP4.0.5RC1/Apache DSO/W2K Server)
If this is expected behavior in PHP, it would better to be described in the Manual.
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Full Bug description available at: http://bugs.php.net/?id=9983