3 ms·

What do you mean?

• TylerE 13y ago
  I'd like to see your defintion of structural typing in PHP. (Hint: Not casts, not lots of manual gettype)
  • jafaku 13y ago
    I don't have a definition, I just use the thing. That's why I'm asking, I'm not a computer scientist. Eg: $f = function helloAction(Http\Request $request) { $response = new Http\Response("Hello " . $request->query->get('name'), 200); $response->setMa // at this point the IDE will show a list of methods like 'setMaxAge($time)', because it knows its type }; Now I can pass $f somewhere else, like this: $someObject->someMethod($f); And the method can accept it like this: protected method someMethod($f) {} // no checks! Or like this: protected method someMethod(\Closure $f) {} // only an argument of type Closure will be accepted. So those are types for me. If you are asking for something like this: Response $r = new Response(...); Then yeah, PHP doesn't have that. Though I don't know why we would want that, it's kind of redundant.
    • anaphor 13y ago
      Pretty sure those are runtime contracts, not static types. Also see https://en.wikipedia.org/wiki/Structural_type_system https://en.wikipedia.org/wiki/Structural_type_system
    • tel 13y ago
      The redundancy can be alleviated by type inference, but it's also kind of nice. The 'Response' on the left is your expectation about what $r is, while the one on the right is your implementation of that expectation. The separation is very important. Of course, in this example, it's silly and type inference would be used to ensure that you don't need to write the left side. The advantage is that before running your code you can suss out much greater degrees of what your code "could possibly mean". The \Closure bit is a start, but it needs to fail prior to running to be statically typed. It also could potentially include much more information like (\Closure[Http\Request -> Http\Response]) and reject even more bad arguments.