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From: Fritz Trapper on 30 Dec 2009 07:08
Correction:
> def executer(obj, method)
> f.method(1)
> end

Should be:
def executer(obj, method)
obj.method(1)
end
--
Posted via http://www.ruby-forum.com/.

From: Marnen Laibow-Koser on 30 Dec 2009 07:11
Fritz Trapper wrote:
> Thanks for your quick replies.
>
> I see, my scenario is somewhat more complicated, than I wrote in my
> initial posting. The point is, that I want to pass an object and a
> method.
>
> Something like this:
>
> def executer(obj, method)
> f.method(1)
> end
>
> class x
> def test(x)
> p x
> end
> end
>
> o = x.new
> executer(o, test)

Why not just use o.send(:test) ?

Best,
--
Marnen Laibow-Koser
http://www.marnen.org
marnen(a)marnen.org
--
Posted via http://www.ruby-forum.com/.

From: Fritz Trapper on 30 Dec 2009 07:13
Marnen Laibow-Koser wrote:

> Why not just use o.send(:test) ?

Thanks, that helps.
--
Posted via http://www.ruby-forum.com/.

From: Jesús Gabriel y Galán on 30 Dec 2009 07:17
On Wed, Dec 30, 2009 at 1:00 PM, Jeff Peng <jeffpeng(a)netzero.net> wrote:
> Jesús Gabriel y Galán:
>>
>> On Wed, Dec 30, 2009 at 12:42 PM, Fritz Trapper <ajfrenzel(a)web.de> wrote:
>>>
>>> I want to pass a reference to function as parameter to another function
>>> and execute the passed function. Somthing like this:
>>>
>>> def executer(func)
>>>  func(1)
>>> end
>>>
>>> def test(x)
>>>  p x
>>> end
>>>
>>> executer(test)
>>>
>>> How to write this correctly in ruby?
>>
>> A typical way would be using blocks or procs:
>>
>> def executer
>> yield 1
>> end
>>
>> executer {|x| puts "I got #{x}"}
>>
>> If you want something to handle around in a variable:
>>
>> func = lambda {|x| puts "I got #{x}"}
>> executer(&func) # => I got 1
>>
>
> for &func, what's the "&" before "func" here?

A method can receive regular parameters and a "special" block
parameter. The & lets you pass a proc as that special block parameter,
instead of a regular one:

irb(main):033:0> executer(func)
ArgumentError: wrong number of arguments (1 for 0)
from (irb):33:in `executer'
from (irb):33
from :0

Jesus.

From: Jesús Gabriel y Galán on 30 Dec 2009 07:18
On Wed, Dec 30, 2009 at 1:08 PM, Fritz Trapper <ajfrenzel(a)web.de> wrote:
> Correction:
>> def executer(obj, method)
>>    f.method(1)
>> end
>
> Should be:
> def executer(obj, method)
>   obj.method(1)

obj.send(method, 1)

> end

executer(O.new, :the_method)

Jesus.

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