Hi Nathan,
On Thu, Apr 30, 2015 at 6:41 AM, Nathan Bruer <[email protected]> wrote:
> This has been a big issue that I have ran into many times in the past for
> large framework projects, instead of building it out with "strict" types
> like: int, float, string, exc... It makes more sense to allow a user to
> define a psudo-type themselves which PHP will pass the arguments into to be
> "cleaned" by the user then let the function deal with the arguments.
>
> For example:
> function force_int($value){
> return (int) $value;
> }
> function must_be_string($v){
> if(!is_string($v)){
> throw new Exception("Not String");
> }
> return (string) $v;
> }
>
> function foo(*force_int $val, *must_be_string $str){
> // $val will always be an int if it ever gets here
> // $str will always be a string if it gets here
> echo $val, " ", $str;
> }
> foo("foo", "bar"); // returns '0 bar'
> foo("1", "2"); // returns '1 2'
> foo(1, 2); // fatal error because second argument threw exception
> foo(1, "2") // returns '1 2'
> foo("hi", 2) // fatal error because second argument threw exception
> foo("hi", "2") // returns '0 2';
>
I agree. Forcing type is headache and such check is useful.
The problem with this approach is overhead. I would like to resolve this in
2 ways.
1. DbC - Check parameter types during development by DbC and make
sure all callee satisfies contract.
2. True weak type hint - Make weak mode type hint truly weak. Accept
any form of the specified types.
Since we won't have DbC for PHP 7.0, I'll discuss only option 2.
function foo(int $i) {
switch(gettype($i)) {
case 'integer':
case 'float":
foo_numeric($i);
break;
default:
// We don't want to accept gmp/string
throw new Exception('Type error');
}
}
Ideal solution would be DbC. Anyway, above example is a little more
efficient
than calling pseudo type checker functions (for now). Pseudo type checker
is useful and requires less code. I'm neutral to have it or not.
Regards,
--
Yasuo Ohgaki
[email protected]
