[bitc-dev] Moose, rugs, and separate compilation

[Gelf Mrogen]

> apparent vs. actual type

I've seen these terms used in OOP contexts, but I was using them somewhat 
informally here.  I mean that dispatch should be based on what you know of the 
types locally (lexically).  Or simpler still: instance selection should be static and 
not dynamic (though with this phrasing there is a caveat that with existential 
types the static instance chosen is arguably a dynamic dispatch).

>  The problem is that I, as a caller, cannot alter what was in scope at the callee 
> after the fact. This means that it is sometimes impossible for me to introduce
> new specializations for new types.

Agreed - the caller cannot alter what was in scope at the callee.   This is 
important, since the callee code relies on the instances it has chosen for its 
correctness.   If the callee code isn't abstract or polymorphic enough, it would 
need to be fixed.

The only problem I see here is that the conventional notation for type classes (a la 
haskell) is sufficiently verbose that it discourages making code as fully abstract as 
it could (should) be.   That, and problems related to inefficient separate 
compilation in the absence of link-time specialization.

Matt



      
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.coyotos.org/pipermail/bitc-dev/attachments/20090306/f4c2a9f4/attachment.html