Find the parameters of each method in a class

[Chris Gunnels]

Is there a way to find the parameters of each method in a class? For
instance I have a class like:

class CoolClass
def meth_one(p1,p2)
...
end

def meth_two(p1,p2,p3)
...
end
end

I can run:
cc = CoolClass.new
cc.public_methods(false)

and it will return an array of all the public methods
(['meth_one','meth_two']).

Is there a way to find the parameters of each method from the example
above?

 

[Jason Roelofs]

[Note: parts of this message were removed to make it a legal post.]

You can find the arity of said methods, but afaik not the names of the
parameters:

CoolClass.instance_methodmethod_one).arity # => 2
CoolClass.instance_methodmethod_two).arity # => 3

Jason

 

[Benoit Daloze]

In Ruby 1.9.2:

irb(main):001:0> class C
irb(main):002:1> def meth(a,bb, ccc =3D nil, &b)
irb(main):003:2> end
irb(main):004:1> end
=3D> nil
irb(main):005:0> C.instance_methodmeth).parameters
=3D> [[:req, :a], [:req, :bb], [pt, :ccc], [:block, :b]]

But you will not get the names for C methods like String#tr, just the
type of the parameters.

You can find the arity of said methods, but afaik not the names of the
parameters:

CoolClass.instance_methodmethod_one).arity # =3D> 2
CoolClass.instance_methodmethod_two).arity # =3D> 3

Jason

Is there a way to find the parameters of each method in a class? For
instance I have a class like:

class CoolClass
=A0def meth_one(p1,p2)
=A0...
=A0end

=A0def meth_two(p1,p2,p3)
=A0...
=A0end
end

I can run:
cc =3D CoolClass.new
cc.public_methods(false)

and it will return an array of all the public methods
(['meth_one','meth_two']).

Is there a way to find the parameters of each method from the example
above?

 

[Chris Gunnels]

Thanks Jason. That gets me a little further. For those that don't know,
arity returns an indication of the number of arguments accepted by a
method.

http://ruby-doc.org/core/classes/UnboundMethod.html#M001131

 

[Chris Gunnels]

In Ruby 1.9.2:

irb(main):001:0> class C
irb(main):002:1> def meth(a,bb, ccc = nil, &b)
irb(main):003:2> end
irb(main):004:1> end
=> nil
irb(main):005:0> C.instance_methodmeth).parameters
=> [[:req, :a], [:req, :bb], [pt, :ccc], [:block, :b]]

But you will not get the names for C methods like String#tr, just the
type of the parameters.

2010/1/26 Jason Roelofs <[email protected]>:

Dang thats awesome and exactly what I need! Why can't it be in 1.8?

 

[Ryan Davis]

In Ruby 1.9.2:
=20
irb(main):001:0> class C
irb(main):002:1> def meth(a,bb, ccc =3D nil, &b)
irb(main):003:2> end
irb(main):004:1> end
=3D> nil
irb(main):005:0> C.instance_methodmeth).parameters
=3D> [[:req, :a], [:req, :bb], [pt, :ccc], [:block, :b]]
=20
But you will not get the names for C methods like String#tr, just the
type of the parameters.
=20
2010/1/26 Jason Roelofs <[email protected]>:

=20
Dang thats awesome and exactly what I need! Why can't it be in 1.8?

It can. Look at merb. I think it is in merb-param-protection. Much more =
hacky, but it works.

 

[Roger Pack]

irb(main):005:0> C.instance_methodmeth).parameters
=> [[:req, :a], [:req, :bb], [pt, :ccc], [:block, :b]]

But you will not get the names for C methods like String#tr, just the
type of the parameters.

Dang thats awesome and exactly what I need! Why can't it be in 1.8?

rdp-arguments gem:
=> [[:a], [:bb], [:ccc, "nil"]]

You can get it in 1.9.1 with the methopara gem, too.
GL!
-r