Gennady Bystritsky
10/27/2006 6:35:00 PM
Jacob Fugal wrote:
> On 10/27/06, Gennady Bystritsky <Gennady.Bystritsky@quest.com> wrote:
>> matt neuburg wrote:
>>> Some languages have a "with" construction, where undefined methods
>>> are routed to a designated object. Here's an example from UserTalk:
>>>
>>> with system.startup {
>>> string(license)
>>> }
>>>
>>> UserTalk knows what "string" is, but when it can't find "license" it
>>> reinterprets it as system.startup.license, which works. In
>>> UserTalk, you can even chain these tests:
>>>
>>> with system.temp, system.startup {
>>> string(license)
>>> }
>>>
>>> That means we try system.temp.license and if that doesn't exist we
>>> proceed to system.startup.license.
>>>
>>> So my question is: is Ruby amenable to this kind of construction? Is
>>> there a way to bend the language to that it acts like this? Thx - m.
>>
>> Something like this?
>>
>> def with(*objects)
>> begin
>> yield
>> rescue NoMethodError => exception
>> o = objects.detect { |_o|
>> _o.respond_to? exception.name
>> } or raise
>>
>> o.send exception.name, *exception.args
>> end
>> end
>
> It's a start, but:
>
> 1) I don't think we really want to redispatch NoMethodErrors for
> messages that had an explicit receiver. Only the ones with implicit
> receivers.
>
> 2) it stops execution of the block after redispatching the
> first exception:
>
> with(Time) do
> "aaa".now
> puts "Never get here"
> end # nothing printed
>
> Jacob Fugal
Hmm... I must have misunderstood the OP. I somehow thought that in
"those" languages string(license) translates to calling method "license"
on "string", hence the solution. My bad, sorry.
Gennady.