From: matz@... (Yukihiro Matsumoto)
Date: 2003-11-21T12:58:38+09:00
Subject: Re: "stereotyping" (was: Re: Strong Typing (Re: Managing metadata about attribute types) )

Hi,

In message "Re: "stereotyping" (was: Re: Strong Typing (Re: Managing metadata about attribute types) )"
    on 03/11/21, "Sean O'Dell" <sean@celsoft.com> writes:

|>   * Types (or "interfaces" to avoid confusion) must be independent
|>     from class/module, otherwise they will be misused too often.  Note
|>     that Sean himself once failed to distinguish these two.
|
|I agree, but since classes and interfaces are often synonymous, there could, 
|possibly, be an alternative mechanism to describing interfaces that used 
|class definition in some way.

Possible.

|Please ask me questions.  I'm terrible about making my own new ideas known 
|because I don't anticipate how clearly they will be received.
|
|The way "false promise" was used before, a class could say "I implement this 
|interface" and then NOT implement it, making the statement a lie.  In my new 
|proposal, there is no way to make that statement.  If a class declares "I 
|implement this interface" it is marked as "incomplete" and the declaration is 
|essentially hidden until the last method fulfills the interface requirement.  
|The class makes the statement, but that is basically ignored until 
|fulfillment is complete, and then the class can generate objects which 
|contain a flag for that interface.

At least I need to take time to sit down and read your article
carefully first.

|>   * The appearance matters.  I think the code example in the proposal
|>     does not look like Ruby:

|That was just an example, I threw that in quickly.  Perhaps the interface 
|requirements would appear in the interface definition, but they would not be 
|repeated when the class actually defined the method.

I understand it's not your point.  It's my job to design the syntax
fit with other part of Ruby.

All in all, I'm wondering trade-offs about this proposal.

							matz.