2009/6/29 Cameron Sanders <csanders.personal at functional-analyst.com>:
> I didn't read  your example closely, but, generally....
>
> (obj respondsTo: #isCVLambda) and: [ obj isCVLambda ]
>

can't do that for lambdas, because it traps all DNU's and in this case
a send of #respondsTo: (or any other unknown message) will be
converted into a lambda message send instead of answering expected
result.
Because:

lambda := LambdaSlot id: #x.
lambda foo  ==> lambda( <x> #foo)

> is very general (independent of hierarchy), or if you want to trap people on
> a class tree...
>
> obj isKindOf: CVLambda
>

sorry, but this even worse than using #isXXX

> or trap exceptions for when something doesn't respond to isCVLambda ...
>
> or...
>
> --
> BUT, it will be slower.
>
> an intriguing idea is having Object always respond to any pattern isXXX with
> false, unless the method is explicitly defined. (Now there I go, changing
> the root behavior...)
>

Exactly :)

Maybe it worth add and standardize the #is:
message for Object ?
Which by default can be implemented as:

Object is: object
  ^ self == object

and if you need to add the differentiation, then could be something like:

Object is: object
  ^ object == #lambda or: [ super is: object ]


> -Cam
>
>
> On Jun 29, 2009, at 1:18 PM, Igor Stasenko wrote:
>
>> so, here the question, can i implement the same behavior w/o using
>> #isCVLambda , and
>
>
>



-- 
Best regards,
Igor Stasenko AKA sig.