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--- rfc:comparison_inconsistency [2013/11/10 22:40] – [Function/Method] yohgaki
+++ rfc:comparison_inconsistency [2014/02/05 03:03] (current) – removed yohgaki
@@ Line 1: / Line 1: @@
-====== PHP RFC: Existing comparison and conversion inconsistency  ======
-  * Version: 0.1
-  * Date: 2013-10-31
-  * Author: Yasuo Ohgaki <yohgaki@php.net>
-  * Status: Draft (or Under Discussion or Accepted or Declined)
-  * First Published at: http://wiki.php.net/rfc/comparison_inconsistency
-This RFC is to discuss comparison and conversion inconsistencies in PHP.
-===== Introduction =====
-There are number of in comparison and conversion inconsistencies.
-For example,
-  * https://bugs.php.net/bug.php?id=53104 reports comparison inconsistency in min() function.
-There are number issues of like this.
-Purpose of this RFC is fix inconsistency where it's feasible, otherwise document then fully if it's not documented already.
-===== Inconsistency =====
-==== Conversion/comparison ====
-Type juggling only works for INTEGER or HEX like strings.
-=== HEX ===
-Code
-  var_dump(0x0A);
-  var_dump("0x0A");
-  var_dump((int)"0x0A");
-  var_dump((float)"0x0A");
-  var_dump(intval("0x0A"));
-  var_dump(floatval("0x0A"));
-Output
-  int(10)
-  string(4) "0x0A"
-  int(0)
-  float(0)
-  int(0)
-  float(0)
-Code
-  if (0x0A == '0x0A') {
-    echo "0x0A == '0x0A'".PHP_EOL;
-  }
-  if (0x0A == "0x0A") {
-    echo '0x0A == "0x0A"'.PHP_EOL;
-  }
-Output
-x0A == '0x0A'
-x0A == "0x0A"
-=== Octal ===
-Code
-  var_dump(010);
-  var_dump("010");
-  var_dump((int)"010");
-  var_dump((float)"010");
-  var_dump(intval("010"));
-  var_dump(floatval("010"));
-Output
-  int(8)
-  string(3) "010"
-  int(10)
-  float(10)
-  int(10)
-  float(10)
-CODE
-  if (010 == '010') {
-    echo "010 == '010'".PHP_EOL;
-  }
-  if (010 == "010") {
-    echo '010 == "010"'.PHP_EOL;
-  }
-OUTPUT
-  (NONE)
-=== BINARY ===
-Code
-  var_dump(0b110);
-  var_dump("0b110");
-  var_dump((int)"0b110");
-  var_dump((float)"0b110");
-  var_dump(intval("0b110"));
-  var_dump(floatval("0b110"));
-Output
-  int(6)
-  string(5) "0b110"
-  int(0)
-  float(0)
-  int(0)
-  float(0)
-CODE
-  if (0b010 == '0b010') {
-    echo "0b010 == '0b010'".PHP_EOL;
-  }
-  if (0b010 == "0b010") {
-    echo '010 == "010"'.PHP_EOL;
-  }
-OUTPUT
-  (NONE)
-==== Function/Method ====
-=== min() function ===
-https://bugs.php.net/bug.php?id=53104
-This is not a bug. If one of operand is BOOL(or NULL), both operands are converted to BOOL and evaluated as BOOL. It may be good idea that document this behavior in min() manual.
-=== Return value of wrong internal function/method parameters ===
-If not all, almost all functions return NULL when required function parameter is missing or wrong type. However, almost all functions return FALSE when they have errors.
-The manual has document for this behavior
-http://www.php.net/manual/en/functions.internal.php
-  Note: If the parameters given to a function are not what it expects, such as passing an array
-  where a string is expected, the return value of the function is undefined. In this case it will
-  likely return NULL but this is just a convention, and cannot be relied upon.
-This behavior could be cause of bug in scripts. For instance,
-  if (FALSE === some_func($wrong_parameter)) {
-     // Error happend!
-  } else {
-     // OK to go
-  }
-Users should not rely on return value as it may return NULL for wrong parameters. Users should rely on error/exception handler for such case as internal functions raise E_WARNING in this case. (If there are function that does not raise error, it is subject to be fixed.)
-It may be good to add use of error/exception handler as best practice in the manual.
-http://www.php.net/manual/en/functions.internal.php
-There are bug reports that complain return value inconsistency. The document could be improved with more explanations.
-== Related Bug Reports ==
-  * https://bugs.php.net/bug.php?id=60338 (Returns value for wrong key())
-  * https://bugs.php.net/bug.php?id=64860 (returns NULL for wrong file parameter)
-  * https://bugs.php.net/bug.php?id=65986 (returns NULL for wrong parameter)
-  * https://bugs.php.net/bug.php?id=65604 (returns NULL for too huge parameter, probably)
-  * https://bugs.php.net/bug.php?id=59225 (returns NULL when it should return FALSE? when server is not accessible?)
-  * https://bugs.php.net/bug.php?id=65910 (returns NULL for wrong parameter)
-  * https://bugs.php.net/bug.php?id=62492 (returns NULL for wrong parameter)
-  * https://bugs.php.net/bug.php?id=44049 (returns NULL for wrong parameter by mistake? Expecting prepared query params?)
-  * https://bugs.php.net/bug.php?id=64140 (returns NULL for wrong parameter without error/exception?)
-Bug reports are not verified carefully. Removing wrong one, adding proper one is appreciated.
-== Developer Guideline ==
-  * Internal function/method should raise error(or exception) for invalid parameters. (parse parameters function does this)
-  * Internal function/method is better to return NULL for invalid parameters as most functions do.
-  * Internal function/method is better to return FALSE for other errors.
-== User Guideline ==
-  * User should not rely return value only for failure condition, but should rely error/exception handler for failure also.
-===== Proposal =====
-Not yet.
-===== Backward Incompatible Changes =====
-Not yet.
-===== Proposed PHP Version(s) =====
-PHP 6.0 probably.
-===== Impact to Existing Extensions =====
-Not yet.
-===== New Constants =====
-Not yet.
-===== php.ini Defaults =====
-If there are any php.ini settings then list:
-  * hardcoded default values
-  * php.ini-development values
-  * php.ini-production values
-Not yet.
-===== Open Issues =====
-Make sure there are no open issues when the vote starts!
-===== Unaffected PHP Functionality =====
-List existing areas/features of PHP that will not be changed by the RFC.
-This helps avoid any ambiguity, shows that you have thought deeply about the RFC's impact, and helps reduces mail list noise.
-===== Future Scope =====
-This sections details areas where the feature might be improved in future, but that are not currently proposed in this RFC.
-===== Proposed Voting Choices =====
-Include these so readers know where you are heading and can discuss the proposed voting options.
-===== Patches and Tests =====
-Links to any external patches and tests go here.
-If there is no patch, make it clear who will create a patch, or whether a volunteer to help with implementation is needed.
-Make it clear if the patch is intended to be the final patch, or is just a prototype.
-===== Implementation =====
-After the project is implemented, this section should contain
-  - the version(s) it was merged to
-  - a link to the git commit(s)
-  - a link to the PHP manual entry for the feature
-===== References =====
-Links to external references, discussions or RFCs
-===== Rejected Features =====
-Keep this updated with features that were discussed on the mail lists.
-===== ChangeLog =====
-  * 2013/10/31 - Initial version.

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