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Subject: Re: [PHP-DEV] Strict typing
From: smalyshev@sugarcrm.com (Stas Malyshev)

Hi!

> I'm sorry but I have no idea what you're talking about there =\ PHP
> has a bunch of different types, the current type hinting (typechecking

"int" is a different kind of type from Zend_Controller_Factory and 
SimpleXML - the same kind of types are "int" and "object". The former 
are engine types (IS_INTEGER, IS_OBJECT), the latter are classes.

> I very much can, it's just not my intention. I want to be able to use
> type hinting/type checking as a sanity check. If I write a method
> whose signature is foo(int $n) I signal my intention to only accept

Then you should use statically typed language. There's no law saying 
every code on the planet should be written in PHP, and PHP is not a 
statically typed language. So by bolting static typing onto it you are 
using wrong tool for the job.

> If PHP was meant to prevent programmers from controlling the type of
> their variables then I'm afraid there's been a misunderstanding and

PHP and dynamic languages in general are not preventing people from 
knowing the types of variables, they however remove a number of 
annoyances that come with static types. You want to bring all those back 
- and that without the benefits that are compensating for those 
annoyances in compiled languages - meaning being sure upfront that the 
code always gets proper data in proper places. You don't know that 
unless you statically type and compile your whole code - so you just 
traded flexibility and API agility for nothing.

> I'm not sure what you meant by "objects of classes can not [be
> converted into another type]". Arrays can be cast as booleans (false

There are no generic rules that allow conversion between two classes - 
such as SimpleXML and Exception, for example. In general, conversions 
between classes don't happen in the engine. Conversion between IS_* 
types happen all the time.

> TL;DR: I always thought PHP would help me control the type of my
> variables instead of forcing my userland code to mirror PHP's internal
> functions.

If you want strict typing ("control the type of my variables") I'm 
afraid you're using not only wrong language but wrong paradigm. You 
should be using statically typed language. Try C# or Java or Scala or 
something like that. Just having parameter typing won't help you - you'd 
just kick the problem around the code, it will be now it variables 
upstream, etc.
-- 
Stanislav Malyshev, Software Architect
SugarCRM: http://www.sugarcrm.com/
(408)454-6900 ext. 227