ID: 37016
Comment by: voteronpaul at usa dot com
Reported By: a at b dot c dot de
Status: Assigned
Bug Type: Scripting Engine problem
Operating System: Windows XP
PHP Version: 5.1.2
Assigned To: derick
New Comment:
Vote Ron Paul!
Legalize Freedom!
Previous Comments:
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[2007-09-09 04:45:52] a at b dot c dot de
_Would it be sufficient if:_ instead of prefixing the lambda function
with a NUL it were to be prefixed by '__'? Since PHP has (always?)
claimed symbols starting with those characters for magical purposes
anyone who is already declaring functions with names like "__lambda_1"
is already effectively on notice that their code might break (moreso
than someone who, in PHP 4, say, declared a function named "clone").
As it stands, higher-order functions are pretty much unworkable:
attempts to construct new functions from existing ones are hamstrung by
the fact that the existing functions may themselves be lambda functions
and therefore unmentionable in the new function's body.
Currently the only valid workaround would appear to be something like
(to use the notation of the original examples)
$dfun = create_function('','$d1=chr(0)."'.substr($d1,1).'"; return
!$d1();');
Which of course needs to be further modified to deal with the cases
where $d1 is not the name of a lambda function.
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[2007-01-18 13:57:08] a dot steenveld at id dot umcn dot nl
hmmm.... I've not done enough reseachr in the bugreports. Well, I did,
but too late. :(
While looking for a similar problem I found a likely cause for this
problem, found a workaround for my problem, and suggested a change and
filed a bug report.
See report #40160, hope you can use it.
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[2006-04-08 11:51:18] [EMAIL PROTECTED]
I can reproduce this... let's see if I can come up with a fix.
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[2006-04-08 05:35:12] a at b dot c dot de
Description:
------------
When inserting (the name of) a lambda function provided by
create_function into a string that will be used to create a second
lambda function, the second function fails to parse. The parse error
message makes what appears to be a spurious complaint about the code;
only Test 5's error message makes sense (plus, it seems there is no
"callable" version of a lambda function's name).
(Cf. bug #10721 - parser chokes on lambda function names in eval'd
code)
Reproduce code:
---------------
I made five distinct tests to bracket the issue:
TEST 1:
// Creating a function that calls an ordinary function (explict name)
function always_true(){return true;}
$afun = create_function('', 'return !always_true();');
echo "Calling $afun() " . ($afun() ? "returns true\n" : "returns
false\n");
TEST 2:
// Creating a function that calls an ordinary function (variable name)
function always_true(){return true;}
$b1 = 'always_true';
$bfun = create_function('','return !'.$b1.'();');
echo "Calling $bfun() " . ($bfun() ? "returns true\n" : "returns
false\n");
TEST 3:
// Creating a function that calls an anonymous function (explicit
name);
$c1 = create_function('','return true;');
$cfun = create_function('','return !'.chr(0).'lambda_3();');
echo "Calling $cfun() " . ($cfun() ? "returns true\n" : "returns
false\n");
TEST 4:
// Creating a function that calls an anonymous function (variable
name)
$d1 = create_function('','return true;');
$dfun = create_function('','return !'.$d1.'();');
echo "Calling $dfun() " . ($dfun() ? "returns true\n" : "returns
false\n");
TEST 5:
// Using is_callable to get a callable version of anonymous function
name
$e1 = create_function('', 'return true;');
if(!is_callable($e1,false,$callable_e1)) die("Couldn't call anonymous
function.");
echo "Using $callable_e1 as name of anonymous function\n";
$efun = create_function('','return !'.$callable_e1.'();');
echo "Calling $efun() " . ($efun() ? "returns true\n" : "returns
false\n");
Expected result:
----------------
TEST 1:
Calling lambda_1() returns false
TEST 2:
Calling lambda_1() returns false
TEST 3:
Calling lambda_2() returns false
TEST 4:
Calling lambda_2() returns false
TEST 5:
Using lambda_1 as name of anonymous function [?]
Calling lambda_2() returns false
Actual result:
--------------
Actual Results:
TEST 1:
Calling lambda_1() returns false
TEST 2:
Calling lambda_1() returns false
TEST 3:
Parse error: parse error, unexpected '}' in test.php : runtime-created
function on line 1
Fatal error: Function name must be a string in test.php on line 4
TEST 4:
Parse error: parse error, unexpected '}' in test.php : runtime-created
function on line 1
Fatal error: Function name must be a string in test.php on line 4
TEST 5:
Using as name of anonymous function
Parse error: parse error, unexpected ')' in test.php : runtime-created
function on line 1
Fatal error: Function name must be a string in test.php on line 6
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Edit this bug report at http://bugs.php.net/?id=37016&edit=1
