method return values' types

[Jonathan Bachrach <Jonathan.Bachrach@ircam.fr>]

It is quite clear to me that being able to declare the return types of
method's is very important.  Unfortunately, at present, DYLAN
provides no mechanism for doing so -- only a future way to declare
return types of generic-function's.  Of course this is insufficient as
method's of the same generic-function could have different return
types.  

In order to expedite the design of such a feature I propose the
following syntax:

  (define-method variable-name parameter-list form-1 form-2 ...)

  where parameter-list ::=
  ({required | (required specializer)}*
   [#next next]
   [#rest rest]
   [#key {keyparam | ([keyword] keyparam [default])}*]
   [#result {result-type | (result-type-1 result-type-2 ...)}]) 
		
I opted to name the return-value token `#result' but other better
names might be `#return' or more succinctly `#:' or `#=>'.  

What do people think?

-- Jonathan bachrach

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