[Haskell-cafe] Re: [Haskell] Re: Trying to install binary-0.4

[Isaac Dupree]

Ross Paterson wrote:
> I would make "API extended only" a bit more precise: any module that uses
> explicit import lists will not be affected by the changes.  So one can
> add classes, types and functions, but not instances (except where either
> the class or the type is new).

okay

> You probably can't add data constructors
> or fields, and have to be careful with new methods.

If they're exported and new members of existing classes/datatypes, then 
you can't add them, because they might be imported with 
"class/typename(..)". (right?)

What about semantic changes to the API?  Including, adding a default to 
a class method changes the default from 'undefined', which someone might 
have relied on as the default (although it seems unlikely).

Isaac