On Mar 20, 2009, at 16:18, Rich Hickey wrote:
>> Providing a :default implementation for multimethods is a very common
>> and useful technique, but it is really useful only for multimethods
>> that dispatch on a single argument.
>
> I disagree about that. No dispatch value, composite or not, is s
On Mar 20, 2009, at 16:35, Paul Stadig wrote:
> You could use multiple multi-methods:
...
Not pretty, as you said, but also not quite the same in behaviour as
a single multimethod dispatching on both arguments. Multiple dispatch
can be made symmetric in the arguments, whereas a chain of
m
It's also not as maintainable as using a single multi-method.
Like I said, not pretty, but it works.
Paul
On Fri, Mar 20, 2009 at 11:38 AM, David Nolen wrote:
> This works well as long as you don't mind the perf hit for the second
> dispatch :)
>
>
> On Fri, Mar 20, 2009 at 11:35 AM, Paul Stad
This works well as long as you don't mind the perf hit for the second
dispatch :)
On Fri, Mar 20, 2009 at 11:35 AM, Paul Stadig wrote:
> You could use multiple multi-methods:
>
> user=> (defmulti plus-int (fn [x y] (type y)))
> #'user/plus-int
> user=> (defmethod plus-int :default [x y] (println
You could use multiple multi-methods:
user=> (defmulti plus-int (fn [x y] (type y)))
#'user/plus-int
user=> (defmethod plus-int :default [x y] (println "the first is an int"))
#
user=> (defmethod plus-int java.lang.Double [x y] (println "one of each"))
#
user=> (defmulti plus (fn [x y] (type x)))
On Mar 20, 10:56 am, Konrad Hinsen wrote:
> Providing a :default implementation for multimethods is a very common
> and useful technique, but it is really useful only for multimethods
> that dispatch on a single argument.
I disagree about that. No dispatch value, composite or not, is still a
v
Providing a :default implementation for multimethods is a very common
and useful technique, but it is really useful only for multimethods
that dispatch on a single argument. What I am looking for is an
equivalent technique for multiple-argument dispatch.
Suppose you have a multimethod + of
