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Date: Tue, 3 Feb 2015 20:07:57 +0100
To: Christoph Becker <cmbecker69@gmx.de>
Cc: Thomas Bley <mails@thomasbley.de>, dmitry@zend.com, ajf@ajf.me,
 nikita.ppv@gmail.com, internals@lists.php.net
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Subject: Re: [PHP-DEV] What do we need strict scalar type hints for?
From: sd@sven-drieling.de (Sven Drieling)

Am Mon, 02 Feb 2015 23:38:21 +0100
schrieb Christoph Becker <cmbecker69@gmx.de>:

Hallo,

> >>  addVat(-1);
> 
> Well, my point was that even a strict type system doesn't necessarilly
> catch all erroneous/undesired arguments.  Even if addVat() properly
> handles negative numbers, and maybe even zeroes, there are functions
> that can't.

What about scalar type declaration in userland?


namespace mytypes;


declare scalartype amount($amount) {
   if (!is_int($amount) && !is_float($amount)) {
        throw new InvalidArgumentException('Argument amount 
        must be of the type int|float, '.gettype($amount).' given');
   }
}


function addVat(mytypes\amount $amount) {
    return round($amount*1.19, 2);
}

addVat(42)   // OK
addVat("42") // OK
addVat(-42)  // OK
addVat(42.0) // OK
addVat(true) // Exception


var mytypes\amount $amount = 0;

$amount = 42;   // OK
$amount = "42"; // OK
$amount = true; // Exception



tschuess
      [|8:)