Static typing (was Re: Java guy interested in Python)

[D-Man]

On Fri, Mar 09, 2001 at 09:52:09AM +0000, Hamish Lawson wrote:
| Michael Hudson wrote:
| 
| > If you type-annotate this, you might write (using entirely made up
| > syntax):
| > 
| > def write16(file : <file>, int : <int>):
| >     file.write(struct.pack("h",int))
| > 
| > but then what about passing in a StringIO object, or some user 
| > wrapper of a file object?  What makes a "<file>"?  At the moment, 
| > it's just a loose collection of methods, some of which are optional 
| > in some circumstances.
| 
| Wouldn't there be a hierarchy of interface types for file-like objects,
| with some interfaces specifying more methods than others? You'd then
| choose the interface type that specified the collection of methods that
| you require of your passed object.

Yes.  It's called Java ;-).

| 
| Not-that-I'd-necessarily-want-this-all-of-the-time-ly yours,

I certainly don't.


I do like the ERR side of compile-time type checking however.  Perhaps
someone should create a Py-lint that will check python source for this
sort of thing.  Then again maybe it's already called PyUnit or
doctest.

-D