Idiom -- is there a better way?

[Mark Probert]

Hi ..

I am doing indirect dispatch, something like:

class Foo
def bar(fn)
eval "self.#{fn}"
end
end

class Bar < Foo
def blah
puts "blah here"
end
end

f = Bar.new
f.bar("blah")

It works however I am sure there must be a nicer way of doing the bar(fn)
stuff. Any ideas?

TIA,
-mark.

 

[Kevin Howe]

class Foo

def bar(fn)
eval "self.#{fn}"
end
end

...nicer way of doing the bar(fn) stuff. Any ideas?

Replace eval "self.#{fn}" with method(fn).call

 

[Alexey Verkhovsky]

Hi ..

I am doing indirect dispatch, something like:
class Foo
def bar(fn)
eval "self.#{fn}"
end
end

Try self.send(fn) instead.

 

[trans. (T. Onoma)]

On Wednesday 20 October 2004 12:54 pm, Mark Probert wrote:
| Hi ..
|
| I am doing indirect dispatch, something like:
|
| class Foo
| def bar(fn)
self.send(fn)
| end
| end
|
| class Bar < Foo
| def blah
| puts "blah here"
| end
| end
|
| f = Bar.new
| f.bar("blah")
|
| It works however I am sure there must be a nicer way of doing the bar(fn)
| stuff. Any ideas?
|
| TIA,
| -mark.

--
( o _ カラãƒ
// trans.
/ \ (e-mail address removed)

I don't give a damn for a man that can only spell a word one way.
-Mark Twain

 

[Gavin Kistner]

class Foo
def bar(fn)
eval "self.#{fn}"
end
end

class Bar < Foo
def blah
puts "blah here"
end
end

f = Bar.new
f.bar("blah")

Does the function need to be a string argument?

f.bar( f.method( :blah ) ) # Pass the actual method reference

or, as others have noted:

class Foo
def bar( meth_name )
self.method(m).call
end
end
...
f.bar( :blah )

 

[Robert Klemme]

Hi ..

I am doing indirect dispatch, something like:

class Foo
def bar(fn)
eval "self.#{fn}"
end
end

class Bar < Foo
def blah
puts "blah here"
end
end

f = Bar.new
f.bar("blah")

It works however I am sure there must be a nicer way of doing the bar(fn)
stuff. Any ideas?

TIA,
-mark.

There's no need for method bar because that is built into Ruby alread:
Object#send does the job:

class Bar
def blah
puts "blah here"
end
end

blah here
=> nilblah here
=> nil
Kind regards

robert

 

[Mark Probert]

Hi ..

Does the function need to be a string argument?

Yup. What I am doing is taking a YAML entry and converting it into a
method call for a derived class.

Thanks to all for the help.

 

[John Carter]

#On Thu, 21 Oct 2004, Mark Probert wrote:
#
#Try

class Foo
def bar(fn)
send(fn)
end
end

class Bar < Foo
def blah
puts "blah here"
end
end

f = Bar.new
f.barblah)




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