On 12/07/2014 03:31 PM, Stefan Monnier wrote:
>> That's a terrible idea. It makes it much harder to reason about the
>> correct operation of programs, since now it makes it virtually
>> impossible to implement find-definition functionality without lots of
>> type inference.
> 
> That's indeed the main problem, and I agree it's a serious one.
> 
>> There's also the runtime overhead of dynamic dispatch.
> 
> That's not relevant: one way or another there is dynamic dispatch,
> regardless what system we use.

That's not true: if we send messages to objects, we can only know the
code to execute after examining the object. If we invoke functions
directly, we know *statically* what code runs where.

>> Common Lisp solved this problem 20 years ago with namespaces. We should
>> just implement CL namespaces instead of trying to shoehorn Smalltalk
>> into the language. Would you accept a CL packages implementation?
> 
> Last time this was discussed (a year ago, maybe?), we neded turning it
> down, mostly because `M-x grep RET' can't be used for find-definition
> and find-uses.

*Any* solution that frees developers from spelling all symbols in full
will have that disadvantage. At least namespaces make it relatively
symbol to determine the fully-resolved symbol from lexical context
without requiring a full type inference pass.