Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Fri, May 4, 2012 2:10 pm, Kris Craig wrote: On Fri, May 4, 2012 at 11:48 AM, Richard Lynch c...@l-i-e.com wrote: On Wed, May 2, 2012 4:43 am, Pierre Joye wrote: empty() on the other hand, tests if something is empty, and only if it is empty. The result of an expression can be empty. an expression can also have a value of null. And NULL is empty. No issue here. Expressions can also return , 0, 0.0, 0, array() You really think those should all be empty? Unless I'm missing something here, aren't all those things already considered to be empty?? Here's what the PHP man page for empty() says: The following things are considered to be empty: - ** (an empty string) - *0* (0 as an integer) - *0.0* (0 as a float) - *0* (0 as a string) - *NULL* - *FALSE* - *array()* (an empty array) - *var $var;* (a variable declared, but without a value in a class) I am suggesting that some of those wouldn't make so much sense being empty in an expression. empty(2.0 - 1.9); Might not be 0.0, but that's not the point. For some not-empty values added or subtracted, more or less at the whims of digital float behave would or wouldn't be empty. Furthermore, empty on 0 was originally designed user input via GET/POST so that an option0/option would be empty() -- brain cancer update: http://richardlynch.blogspot.com/search/label/brain%20tumor Donate: https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclickhosted_button_id=FS9NLTNEEKWBE -- brain cancer update: http://richardlynch.blogspot.com/search/label/brain%20tumor Donate: https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclickhosted_button_id=FS9NLTNEEKWBE -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Wed, May 2, 2012 4:43 am, Pierre Joye wrote: empty() on the other hand, tests if something is empty, and only if it is empty. The result of an expression can be empty. an expression can also have a value of null. And NULL is empty. No issue here. Expressions can also return , 0, 0.0, 0, array() You really think those should all be empty? Or you want different behavior for expressions vs variables. I'm assuming virtually everybody would agree THAT is unacceptable... Or are the rules for what is or isn't empty going to also change. Again. -- brain cancer update: http://richardlynch.blogspot.com/search/label/brain%20tumor Donate: https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclickhosted_button_id=FS9NLTNEEKWBE -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Fri, May 4, 2012 at 11:48 AM, Richard Lynch c...@l-i-e.com wrote: On Wed, May 2, 2012 4:43 am, Pierre Joye wrote: empty() on the other hand, tests if something is empty, and only if it is empty. The result of an expression can be empty. an expression can also have a value of null. And NULL is empty. No issue here. Expressions can also return , 0, 0.0, 0, array() You really think those should all be empty? Unless I'm missing something here, aren't all those things already considered to be empty?? Here's what the PHP man page for empty() says: The following things are considered to be empty: - ** (an empty string) - *0* (0 as an integer) - *0.0* (0 as a float) - *0* (0 as a string) - *NULL* - *FALSE* - *array()* (an empty array) - *var $var;* (a variable declared, but without a value in a class) If that's the way it already behaves, then why would keeping it that way even be an issue? If an expression returns any of those things, it's empty. I've been following the debate and I'm still a bit unclear as to what the benefit would be to allowing non-variables in isset(). I mean, as was stated earlier, expressions are neither set nor unset. Furthermore, if you were to assign a variable to any valid expression (empty or otherwise), it would be considered set. Therefore, through simple deductive logic, would an expression passed to isset() not, by definition, *always* return TRUE if the expression itself is syntactically valid? The answer seems to be yes as far as I can tell. And if that is the case, then what value is there in allowing it if the return value is always the same no matter what? --Kris
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
I've been following the debate and I'm still a bit unclear as to what the benefit would be to allowing non-variables in isset(). I mean, as was stated earlier, expressions are neither set nor unset. Furthermore, if you were to assign a variable to any valid expression (empty or otherwise), it would be considered set. Therefore, through simple deductive logic, would an expression passed to isset() not, by definition, *always* return TRUE if the expression itself is syntactically valid? yeah, this wouldn't be much to think about if isset in php wouldn't handle null values as not set. and as I mentioned expressions can return null, so it isn't true that any expression given to isset would always result in true. but I think we were talked this over already, so not much point repeating the same arguments over and over again. to summarize, the following cons were brought up against allowing expressions for isset : - if you pass an undefined constant to isset, you will get unexpected result as isset will raise a notice and can return unexpected result as the constant is casted to string before being passed to isset(btw. this is how expressions work everywhere else, so it isn't a real surprise, but it is a change to the current behavior). - this is a valid concern, but the same problem applies to empty too, so it is a general problem with the current patch/rfc. I think it would be nice mentioning this in the rfc, as this could/will cause a few wtf moments for some people. - isset(CONST) could be seen as defined(CONST) but they are returning different results if CONS is defined with NULL or undefined. - this is a valid concern, and there is no good solution, for isset(CONST) we either go cosistent with isset or declared, but can't do both at the same time. - semantically empty can make sense for expressions, isset doesn't: - yep, the only thing that makes this a little less clear/obvious is the fact that isset in php also checks for value, not only the existence of the variable. - following the previous point, there are much more fluent use-cases for empty(expression) than for isset(expression) - this is true, for null check you should use comparing the value, for other cases empty could be much more useful, only the isset(CONST) could be useful, but I mentioned the problems with that above. after discussing this and thinking it over a few times, I decided that I will drop my case about supporting both empty and isset. I think that keeping the argument handling for isset and empty in sync doesn't worth the possible gotchas. and I now a little less sure about suporting this change for empty(), given how much do we emphasized over the years that empty won't trigger any warning about the non-existent variables. -- Ferenc Kovács @Tyr43l - http://tyrael.hu
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Fri, May 4, 2012 at 1:27 PM, Ferenc Kovacs tyr...@gmail.com wrote: I've been following the debate and I'm still a bit unclear as to what the benefit would be to allowing non-variables in isset(). I mean, as was stated earlier, expressions are neither set nor unset. Furthermore, if you were to assign a variable to any valid expression (empty or otherwise), it would be considered set. Therefore, through simple deductive logic, would an expression passed to isset() not, by definition, *always* return TRUE if the expression itself is syntactically valid? yeah, this wouldn't be much to think about if isset in php wouldn't handle null values as not set. Hmm I'd never really thought about that before. But now that you mention it, that does sound like a problem. Honestly, I can see no value in maintaining a different standard for what constitutes a set or not-set variable depending on the function. While I understand Pierre's point that people have used $var = NULL; in the past to unset variables, I don't think we should actually be supporting that. After all, $var = (anything, including nothing) is, by definition, setting the variable to something (or nothing). I would analogize this to a printed dictionary. Let's say you look up the word, glarbofatass. It's not there. So you take out another dictionary and look it up again. There's an entry for it, but the entry says, This word has no meaning. In the first dictionary, glarbofatass is not set. In the second dictionary, glarbofatass is set to the state of having no meaning. Nevertheless, it *is* set. I've never thought of setting something to NULL as being *literally *the same thing as unsetting it (though the purpose and end result are mostly the same). If we didn't have an unset() function, I might feel differently about this. But we do, so really I don't see why = NULL needs to be an alias for unset(). To be honest, I doubt this would pose any real BC breakage, either, unless someone can point me to an instance where somebody uses = NULL to unset a variable and then checks it with isset() later, expecting FALSE. Personally, I would consider = NULL == unset() but only as it pertains to isset() to be a bug that should be fixed, not a feature that should be preserved. And if we make that change (perhaps target it for PHP 6 since it would nonetheless pose a fundamental logic change, albeit an extremely minor and low-impact one), then this RFC suddenly makes a lot more sense while allowing the scope to be limited to empty() without creating any annoying contradictions. --Kris
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
Hmm I'd never really thought about that before. But now that you mention it, that does sound like a problem. Honestly, I can see no value in maintaining a different standard for what constitutes a set or not-set variable depending on the function. While I understand Pierre's point that people have used $var = NULL; in the past to unset variables, I don't think we should actually be supporting that. After all, $var = (anything, including nothing) is, by definition, setting the variable to something (or nothing). I would analogize this to a printed dictionary. Let's say you look up the word, glarbofatass. It's not there. So you take out another dictionary and look it up again. There's an entry for it, but the entry says, This word has no meaning. In the first dictionary, glarbofatass is not set. In the second dictionary, glarbofatass is set to the state of having no meaning. Nevertheless, it *is* set. I've never thought of setting something to NULL as being *literally *the same thing as unsetting it (though the purpose and end result are mostly the same). If we didn't have an unset() function, I might feel differently about this. But we do, so really I don't see why = NULL needs to be an alias for unset(). To be honest, I doubt this would pose any real BC breakage, either, unless someone can point me to an instance where somebody uses = NULL to unset a variable and then checks it with isset() later, expecting FALSE. Personally, I would consider = NULL == unset() but only as it pertains to isset() to be a bug that should be fixed, not a feature that should be preserved. And if we make that change (perhaps target it for PHP 6 since it would nonetheless pose a fundamental logic change, albeit an extremely minor and low-impact one), then this RFC suddenly makes a lot more sense while allowing the scope to be limited to empty() without creating any annoying contradictions. then maybe you should open a separate rfc and thread for that. btw. $foo = null; doesn't equals/aliases unset($foo); only isset() written in a way so that it checks the existence of the variable AND if it exists then checks that it's value isn't null. maybe this isn't nice for a newcommer to the language, but it is how isset works for a pretty long time now, and changing it would be a major BC break. not impossible, but that would definitively deserve a separate RFC and discussion. -- Ferenc Kovács @Tyr43l - http://tyrael.hu
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
Anthony Ferrara wrote: I voted for the ability to use an expression for isset() as well, since I agree with Ferenc, it's a matter of consistency. Sure, the use-case for isset() is definitely weaker than for empty(), but at the same token they are definitely related... I just can't help feeling that it is the wrong use of both. If the function is returning a value, then it's returning a value that needs to be used somewhere so the work flow handles that. If the function returns nothing instead that just seems wrong and needs to be handled better. I'm used to getting back 'false' if the function failed and just check for that so why would there be any logical reason for using isset or empty to check a function return? -- Lester Caine - G8HFL - Contact - http://lsces.co.uk/wiki/?page=contact L.S.Caine Electronic Services - http://lsces.co.uk EnquirySolve - http://enquirysolve.com/ Model Engineers Digital Workshop - http://medw.co.uk// Firebird - http://www.firebirdsql.org/index.php -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
2012/5/3 Lester Caine les...@lsces.co.uk:
Anthony Ferrara wrote:
I voted for the ability to use an expression for isset() as well,
since I agree with Ferenc, it's a matter of consistency. Sure, the
use-case for isset() is definitely weaker than for empty(), but at the
same token they are definitely related...
I just can't help feeling that it is the wrong use of both. If the function
is returning a value, then it's returning a value that needs to be used
somewhere so the work flow handles that. If the function returns nothing
instead that just seems wrong and needs to be handled better. I'm used to
getting back 'false' if the function failed and just check for that so why
would there be any logical reason for using isset or empty to check a
function return?
Use case:
// Function definition:
function getFriends()
{
// SQL SELECT or Fetching from XML or Fetching from LDAP or ...
return $resultsAsArray;
}
// Looping on results:
foreach ( getFriends() as $friend )
{
echo $friend[name], \n;
}
// Case where the results are actually not iterated:
$amIAssocial = empty( getFriends() );
1. It it not wrong to return nothing, like empty sets (empty
arrays), it is a valid case.
2. Returning false in the case there is no results would be a bad
idea: not only you would have to put a condition in the function
definition, but you would also require all iterations (e.g. foreach)
to be encapsulated in a condition statement to prevent looping on
false.
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Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
I just can't help feeling that it is the wrong use of both. If the function
is returning a value, then it's returning a value that needs to be used
somewhere so the work flow handles that. If the function returns nothing
instead that just seems wrong and needs to be handled better. I'm used to
getting back 'false' if the function failed and just check for that so why
would there be any logical reason for using isset or empty to check a
function return?
Use case:
// Function definition:
function getFriends()
{
// SQL SELECT or Fetching from XML or Fetching from LDAP or ...
return $resultsAsArray;
}
// Looping on results:
foreach ( getFriends() as $friend )
{
echo $friend[name], \n;
}
// Case where the results are actually not iterated:
$amIAssocial = empty( getFriends() );
This is the exact same thing:
$amIAssocial = !getFriends();
Earlier, I sent this to Lester only:
Most people don't realize that an empty array is already falsy so they
feel the need to use empty. That is the only use-case the RFC gives
for making this change. From the RFC: For example if func() is
expected to return an array, it feels more natural to verify it's
emptiness using empty() instead of !.
--
Herman Radtke
hermanrad...@gmail.com | http://hermanradtke.com
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Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
Patrick ALLAERT wrote:
2012/5/3 Lester Caineles...@lsces.co.uk:
Anthony Ferrara wrote:
I voted for the ability to use an expression for isset() as well,
since I agree with Ferenc, it's a matter of consistency. Sure, the
use-case for isset() is definitely weaker than for empty(), but at the
same token they are definitely related...
I just can't help feeling that it is the wrong use of both. If the function
is returning a value, then it's returning a value that needs to be used
somewhere so the work flow handles that. If the function returns nothing
instead that just seems wrong and needs to be handled better. I'm used to
getting back 'false' if the function failed and just check for that so why
would there be any logical reason for using isset or empty to check a
function return?
Use case:
// Function definition:
function getFriends()
{
// SQL SELECT or Fetching from XML or Fetching from LDAP or ...
return $resultsAsArray;
}
// Looping on results:
foreach ( getFriends() as $friend )
{
echo $friend[name], \n;
}
// Case where the results are actually not iterated:
$amIAssocial = empty( getFriends() );
1. It it not wrong to return nothing, like empty sets (empty
arrays), it is a valid case.
2. Returning false in the case there is no results would be a bad
idea: not only you would have to put a condition in the function
definition, but you would also require all iterations (e.g. foreach)
to be encapsulated in a condition statement to prevent looping on
false.
OK I'm just so used to
if( $rs = $this-mDb-query( $query, $bindVars ) ) {
while( $row = $rs-fetchRow() ) {
}
}
So I can't see where 'empty( $rs-fetchRow() )' would fit into the work flow ...
--
Lester Caine - G8HFL
-
Contact - http://lsces.co.uk/wiki/?page=contact
L.S.Caine Electronic Services - http://lsces.co.uk
EnquirySolve - http://enquirysolve.com/
Model Engineers Digital Workshop - http://medw.co.uk//
Firebird - http://www.firebirdsql.org/index.php
--
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Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Mon, Apr 30, 2012 at 3:50 PM, Patrick ALLAERT patrickalla...@php.net wrote: Hi, 2012/4/12 Nikita Popov nikita@googlemail.com: PS: I added isset() too, to address the consistency concerns mentioned on IRC. I would have voted +1 if it didn't contain the isset() change. None of the examples used in the isset_with_expr.phpt test seems logic to me. Hi: isset and empty are generally think as a pair, and the both even share one ZEND_OP: ZEND_ISSET_ISEMPTY_VAR so I think if you want to change empty, you should also change isset. thanks Care to explain the consistency concerns here? Patrick -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php -- Laruence Xinchen Hui http://www.laruence.com/ -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
hi, On Wed, May 2, 2012 at 10:46 AM, Laruence larue...@php.net wrote: so I think if you want to change empty, you should also change isset. An expression is not set per se. isset goals, by design, from the very 1st day, is to test the existence of a variable and a variable only. empty() on the other hand, tests if something is empty, and only if it is empty. The result of an expression can be empty. Cheers, -- Pierre @pierrejoye | http://blog.thepimp.net | http://www.libgd.org -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Wed, May 2, 2012 at 11:10 AM, Pierre Joye pierre@gmail.com wrote: hi, On Wed, May 2, 2012 at 10:46 AM, Laruence larue...@php.net wrote: so I think if you want to change empty, you should also change isset. An expression is not set per se. isset goals, by design, from the very 1st day, is to test the existence of a variable and a variable only. Returns TRUE if var exists and has value other than NULL, FALSE otherwise. $foo=null; var_dump(isset($foo)); //prints bool(false) empty() on the other hand, tests if something is empty, and only if it is empty. The result of an expression can be empty. an expression can also have a value of null. -- Ferenc Kovács @Tyr43l - http://tyrael.hu
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
hi, On Wed, May 2, 2012 at 11:36 AM, Ferenc Kovacs tyr...@gmail.com wrote: $foo=null; var_dump(isset($foo)); //prints bool(false) No offset meant, but it is totally expected and well known, and as far as I remember documented too. Assigning NULL to a variable unsets it (so to say). empty() on the other hand, tests if something is empty, and only if it is empty. The result of an expression can be empty. an expression can also have a value of null. And NULL is empty. No issue here. Cheers, -- Pierre @pierrejoye | http://blog.thepimp.net | http://www.libgd.org -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Wed, May 2, 2012 at 11:43 AM, Pierre Joye pierre@gmail.com wrote: hi, On Wed, May 2, 2012 at 11:36 AM, Ferenc Kovacs tyr...@gmail.com wrote: $foo=null; var_dump(isset($foo)); //prints bool(false) No offset meant, lapsus :) s,offset,offense, -- Pierre @pierrejoye | http://blog.thepimp.net | http://www.libgd.org -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
Pierre, On Wed, May 2, 2012 at 5:43 AM, Pierre Joye pierre@gmail.com wrote: hi, On Wed, May 2, 2012 at 11:36 AM, Ferenc Kovacs tyr...@gmail.com wrote: $foo=null; var_dump(isset($foo)); //prints bool(false) No offset meant, but it is totally expected and well known, and as far as I remember documented too. Assigning NULL to a variable unsets it (so to say). Well, except that it doesn't unset it. It only fails isset(). The symbol still exists in the symbol table, and the zval is still allocated. That's one reason that isset() can return false, and array_key_exists() will return true. But right now there's no way to check if a symbol exists since isset returns falls for a null value in a symbol (and there's no other way to check it)... Not saying it should change, just that it's a corner case that's not accounted for in the API... I voted for the ability to use an expression for isset() as well, since I agree with Ferenc, it's a matter of consistency. Sure, the use-case for isset() is definitely weaker than for empty(), but at the same token they are definitely related... Anthony empty() on the other hand, tests if something is empty, and only if it is empty. The result of an expression can be empty. an expression can also have a value of null. And NULL is empty. No issue here. Cheers, -- Pierre @pierrejoye | http://blog.thepimp.net | http://www.libgd.org -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Wed, May 2, 2012 at 11:43 AM, Pierre Joye pierre@gmail.com wrote: hi, On Wed, May 2, 2012 at 11:36 AM, Ferenc Kovacs tyr...@gmail.com wrote: $foo=null; var_dump(isset($foo)); //prints bool(false) No offset meant, but it is totally expected and well known, and as far as I remember documented too. Assigning NULL to a variable unsets it (so to say). sure, as I quoted the documentation here. I just wanted to emphasize, that isset not only checks if a variable is set or not, but also checks the value of the variable, which makes your argument (An expression is not set per se. isset goals, by design, from the very1st day, is to test the existence of a variable and a variable only.) much weaker. empty() on the other hand, tests if something is empty, and only if it is empty. The result of an expression can be empty. an expression can also have a value of null. And NULL is empty. No issue here. yeah, but that wasn't my point, I was saying that an expression can also have a value of null, which can be checked by isset, so empty and isset isn't any different in that regard for expressions. -- Ferenc Kovács @Tyr43l - http://tyrael.hu
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
hi Anthony, On Wed, May 2, 2012 at 1:37 PM, Anthony Ferrara ircmax...@gmail.com wrote: I voted for the ability to use an expression for isset() as well, since I agree with Ferenc, it's a matter of consistency. Sure, the use-case for isset() is definitely weaker than for empty(), No, it is not about consistency but goals and meaning. An expression is not set or unset. Anyway, that's not something we can argue about forever :-). Cheers, -- Pierre @pierrejoye | http://blog.thepimp.net | http://www.libgd.org -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Mon, Apr 30, 2012 at 2:39 PM, Nikita Popov nikita@googlemail.comwrote: On Mon, Apr 30, 2012 at 9:50 AM, Patrick ALLAERT patrickalla...@php.net wrote: Hi, 2012/4/12 Nikita Popov nikita@googlemail.com: PS: I added isset() too, to address the consistency concerns mentioned on IRC. I would have voted +1 if it didn't contain the isset() change. None of the examples used in the isset_with_expr.phpt test seems logic to me. Care to explain the consistency concerns here? The concerns came from laruence, so maybe he could drop a comment here :) Basically, empty() and isset() are very similar in their nature, so changing only one of them might seem inconsistent. Personally I don't see much use in allowing expressions in isset(). People being confused by empty(trim($_GET['foo'])) not working is quite common, but I've never heard of somebody trying to use isset() on a function call. The name already makes clear that it's intended for use on variables. albeit I'm not laruence, but I also supported the idea to keep consistency across the allowed params of empty and isset. here is my reasoning: - both isset and empty are language constructs, which many people use almost interchangeability, changing one of them in a way that the same expression works with one of them, but blows up with a parse error seems wrong to me. - maybe you think that isset doesn't really make sense with expressions, but don't forget that this patch would also allow constants to be used with empty/isset, and imo isset(some_constant); would be useful and maybe more straightforward for the people new to the language. -- Ferenc Kovács @Tyr43l - http://tyrael.hu
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
Hi, On Tue, May 1, 2012 at 18:43, Ferenc Kovacs tyr...@gmail.com wrote: albeit I'm not laruence, but I also supported the idea to keep consistency across the allowed params of empty and isset. here is my reasoning: - both isset and empty are language constructs, which many people use almost interchangeability, changing one of them in a way that the same expression works with one of them, but blows up with a parse error seems wrong to me. - maybe you think that isset doesn't really make sense with expressions, but don't forget that this patch would also allow constants to be used with empty/isset, and imo isset(some_constant); would be useful and maybe more straightforward for the people new to the language. So isset(UNDEFINEDCONSTANT) will be isset(UNDEFINEDCONSTANT) which will/should 1) yield a notice, which is unnexpected for isset 2) return true, which is also unexpected. I don't see much point in that. Best regards, -- Etienne Kneuss http://www.colder.ch -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
2012/5/1 Ferenc Kovacs tyr...@gmail.com: On Mon, Apr 30, 2012 at 2:39 PM, Nikita Popov nikita@googlemail.comwrote: - both isset and empty are language constructs, which many people use almost interchangeability, changing one of them in a way that the same expression works with one of them, but blows up with a parse error seems wrong to me. I wish that more wrong usages could blow up with parse errors way before waiting for the incorrect line to be run. While there is some valid use cases for empty() I see none for isset(), it must remain a targeted and specific construct IMHO. - maybe you think that isset doesn't really make sense with expressions, exact :) but don't forget that this patch would also allow constants to be used with empty/isset. That is not a very good think IMO. For the same reason: this patch would also allow writing: empty( false ) or empty( null ) which are both clueless. The fact that this patch would now allow syntactically doubtful things doesn't mean they should be encouraged nor propagated to isset(). Cheers, Patrick -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Tue, May 1, 2012 at 7:24 PM, Patrick ALLAERT patrickalla...@php.netwrote: 2012/5/1 Ferenc Kovacs tyr...@gmail.com: On Mon, Apr 30, 2012 at 2:39 PM, Nikita Popov nikita@googlemail.com wrote: - both isset and empty are language constructs, which many people use almost interchangeability, changing one of them in a way that the same expression works with one of them, but blows up with a parse error seems wrong to me. I wish that more wrong usages could blow up with parse errors way before waiting for the incorrect line to be run. One could argue that then you should pick a compiled language. While there is some valid use cases for empty() I see none for isset(), it must remain a targeted and specific construct IMHO. I agree that there is less valid use-cases, but I feel that keeping the two method consistent about this is more important. - maybe you think that isset doesn't really make sense with expressions, exact :) but don't forget that this patch would also allow constants to be used with empty/isset. That is not a very good think IMO. For the same reason: this patch would also allow writing: empty( false ) or empty( null ) which are both clueless. how is that different than for example writing is_null(null) ? The fact that this patch would now allow syntactically doubtful things doesn't mean they should be encouraged nor propagated to isset(). we are already have that all over the place, I don't think that this particular patch will change anything about that. could you elaborate on this part a little bit? I mean you can write stupid code right now ($null=null;isset($null); instead of isset(null);), I can't see how would this patch worsen the situation. If anything, the silly code could be understood easier, as you wouldn't need to debug the value of the $null variable passed in. So I think that 1, we already too late to prevent that kind of code 2. even if we could, I don't think that the currently discussed patch would really encourage that kind of code 3, there are/could be valid use-cases for isset 4, isset and empty should work the same way in regards of the argument parsing. ofc. this is only my opinion, if I am the minority here, then it is fine too, I just wanted to explain what was the reasoning behind that discussion. -- Ferenc Kovács @Tyr43l - http://tyrael.hu
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
So isset(UNDEFINEDCONSTANT) will be isset(UNDEFINEDCONSTANT) which will/should 1) yield a notice, which is unnexpected for isset 2) return true, which is also unexpected. I don't see much point in that. yep, and if we allow expressions then it is the expected behavior, but you are right that this is will change the current standard that isset/empty can't raise a notice. but this isn't specific to isset, empty will also follow the same pattern. -- Ferenc Kovács @Tyr43l - http://tyrael.hu
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
Sent from my iPhone 在 2012-5-2，3:52，Ferenc Kovacs tyr...@gmail.com 写道： So isset(UNDEFINEDCONSTANT) will be isset(UNDEFINEDCONSTANT) which will/should 1) yield a notice, which is unnexpected for isset 2) return true, which is also unexpected. I don't see much point in that. yep, and if we allow expressions then it is the expected behavior, but you are right that this is will change the current standard that isset/empty can't raise a notice. but this isn't specific to isset, empty will also follow the same pattern. This is really a issue . Thanks -- Ferenc Kovács @Tyr43l - http://tyrael.hu -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
Hi, 2012/4/12 Nikita Popov nikita@googlemail.com: PS: I added isset() too, to address the consistency concerns mentioned on IRC. I would have voted +1 if it didn't contain the isset() change. None of the examples used in the isset_with_expr.phpt test seems logic to me. Care to explain the consistency concerns here? Patrick -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Mon, Apr 30, 2012 at 9:50 AM, Patrick ALLAERT patrickalla...@php.net wrote: Hi, 2012/4/12 Nikita Popov nikita@googlemail.com: PS: I added isset() too, to address the consistency concerns mentioned on IRC. I would have voted +1 if it didn't contain the isset() change. None of the examples used in the isset_with_expr.phpt test seems logic to me. Care to explain the consistency concerns here? The concerns came from laruence, so maybe he could drop a comment here :) Basically, empty() and isset() are very similar in their nature, so changing only one of them might seem inconsistent. Personally I don't see much use in allowing expressions in isset(). People being confused by empty(trim($_GET['foo'])) not working is quite common, but I've never heard of somebody trying to use isset() on a function call. The name already makes clear that it's intended for use on variables. So, I'm not quite sure what I'm supposed to do about this. Should I add two vote options, one for empty() only, one for both? Nikita -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Mon, Apr 30, 2012 at 9:50 AM, Patrick ALLAERT patrickalla...@php.net wrote: Hi, 2012/4/12 Nikita Popov nikita@googlemail.com: PS: I added isset() too, to address the consistency concerns mentioned on IRC. I would have voted +1 if it didn't contain the isset() change. None of the examples used in the isset_with_expr.phpt test seems logic to me. Care to explain the consistency concerns here? Patrick I changed the vote to have three options: Both empty() and isset(), Only empty() or None https://wiki.php.net/rfc/empty_isset_exprs#vote Nikita -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
hi, On Mon, Apr 30, 2012 at 3:05 PM, Nikita Popov nikita@googlemail.com wrote: I changed the vote to have three options: Both empty() and isset(), Only empty() or None https://wiki.php.net/rfc/empty_isset_exprs#vote Please post a top thread to notice everyone about this new vote with a short explanation. Yes, I told you that on IRC a good dozen times since you sent this mail here, but there are good reasons why we do so. For one, many do not follow any single thread on internals and I would not have noticed that mail if I was not on IRC today. So please do it, or the votes result, no matter the outcome, cannot be accepted. Thanks for your understanding, -- Pierre @pierrejoye | http://blog.thepimp.net | http://www.libgd.org -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] [RFC] Allow non-variable arguments to empty() and isset()
On Fri, Apr 13, 2012 at 12:42 AM, Galen Wright-Watson ww.ga...@gmail.com wrote: Just to be clear, under the new behavior, calling empty or isset on undefined variables and undefined array indices shouldn't produce a notice when E_NOTICE is set, correct? Basically, the change isn't regressive. Yup, that's right. So the change is BC-safe :) If this is so, how about adding appropriate regression tests to empty_with_expr.phpt and empty_with_isset.phpt? The normal empty()/isset() behavior (including the suppression of the notice) is tested in a few other tests, that's why I didn't add additional tests for it there :) Nikita -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
