Bug #76054 [Opn->Fbk]: is_a does not accept scalar types
Edit report at https://bugs.php.net/bug.php?id=76054&edit=1
ID: 76054
Updated by: cmb@php.net
Reported by: tom at r dot je
Summary: is_a does not accept scalar types
-Status: Open
+Status: Feedback
Type: Bug
Package: Reflection related
Operating System: any
PHP Version: 7.2.3
-Assigned To:
+Assigned To: cmb
Block user comment: N
Private report: N
New Comment:
ReflectionNamedType::isBuiltin()[1] to the rescue?
[1] <https://www.php.net/manual/en/reflectionnamedtype.isbuiltin.php>
Previous Comments:
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[2018-03-05 18:27:44] tom at r dot je
Description:
------------
I cannot easily work out whether a function can be successfully called with a given set of values if
there are scalar type hints.
Ideally I'd like to do this:
<?php
function foo(string $a, callable $bar) {
}
//I want to check to see whether these arguments can be used to call the function
$arguments = [123, 'not-callable!'];
//Or these valid arguments
// $arguments = ['A string', function() {}]; //This should pass the check
// To do this, I need to check to see whether the arguments match the type hint
$reflect = new ReflectionFunction('foo');
$valid = true;
foreach ($reflect->getParameters() as $i => $param) {
if ($param->getType()) {
//check to see if the type $arguments[$i] matches the type hint
//e.g. would evaluate to is_a('string', 123);
if (!is_a($param->getType()->getName(), $arguments[$i])) $valid = false;
}
}
echo $valid ? 'Function foo can be called with supplied $arguments' : '$arguments do
not match function definition.';
?>
However, because is_a does not allow scalar types in the first argument, it's not possible.
Instead, I need to do this:
<?php
function foo(string $a, callable $bar) {
}
//I want to check to see whether these arguments can be used to call the function
$arguments = [123, 'not-callable!'];
//Or these valid arguments
// $arguments = ['A string', function() {}]; //This should pass the check
// To do this, I need to check to see whether the arguments match the type hint
$reflect = new ReflectionFunction('foo');
$valid = true;
foreach ($reflect->getParameters() as $i => $param) {
if ($param->getType()) {
$type = $param->getType()->getName();
if ($type == 'string' && !is_string($arguments[$i])) $valid = false;
else if ($type == 'int' && !is_int($arguments[$i])) $valid = false;
else if ($type == 'callable' && !is_callable($arguments[$i])) $valid = false;
else if ($type == 'array' && !is_array($arguments[$i])) $valid = false;
}
}
echo $valid ? 'Function foo can be called with supplied $arguments' : '$arguments do
not match function definition.';
?>
Or, alternatively, this hacky as hell workaround:
<?php
function foo(string $a, callable $bar) {
}
//I want to check to see whether these arguments can be used to call the function
$arguments = [123, 'not-callable!'];
//Or these valid arguments
// $arguments = ['A string', function() {}]; //This should pass the check
// To do this, I need to check to see whether the arguments match the type hint
$reflect = new ReflectionFunction('foo');
$valid = true;
foreach ($reflect->getParameters() as $i => $param) {
if ($param->getType()) {
if (!call_user_func('is_' . $param->getType()->getName(), $arguments[$i])) $valid
= false;
}
}
echo $valid ? 'Function foo can be called with supplied $arguments' : '$arguments do
not match function definition.';
?>
Ideally, is_a should support scalar types but perhaps adjusting reflection to allow
$param->getType()->willAccept($value); or similar would work as well because at the moment,
to determine this, we need to do two checks: One for $param->getClass() and another for
$param->getType()
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=76054&edit=1
Thread (3 messages)