Hi guys,

Smalltalk allow to write code with the minor possible coupling. An object 
is coupled with other object only with the messages sent.

Point>>+ otherPoint

	^(self x + otherPoint x) @ (self y + otherPoint y)

The only requirement for otherPoint is to answer #x and #y messages [*].

[*] Answer a message don't means implement a method. Example: a object 
using #doesNotUnderstand: can answer to several messages without a method.


Let's see the StrongTalk implementation:

Point>>+ other <Point> ^<Point>

	^(self x + other x)@(self y + other y)

Why this method require a "complete" Point?  In the not typed version, the 
requirements is more relaxed.

This is the problem with typed systems.  The objects produced don't grow in 
ways don't predicted by the writer.


I think that some type of type annotations helps in the understanding of a 
system and I see the problem with type inference.

My proposal is: Let's use Type Feedback to document a System.

Cheers,

Diego Gomez Deck