Argument-per-argument Passing

ruby-talk
1

This came up in an earlier thread. On occasion I run into situations
where I'd like to pass arguments from one method to another in an
"argument-per-argument" fashion. Take a look at the following:

def give
   return [:a,:b,:c]
end

def give_each
   return *[:a,:b,:c]
end

def take(*args)
   p *args
end

take(:a,:b,:c)
:a
:b
:c

take(give)
[:a, :b, :c]

take(give_each)
[:a, :b, :c]

I'm interested in the last exmple being like the first. I.e.

take(give_each)
:a
:b
:c

Which I am calling argument-per-argument passing.
What is the feasibility of this?

Thanks,
T.

2

"Trans" <transfire@gmail.com> schrieb im Newsbeitrag
news:1106752384.371007.164750@f14g2000cwb.googlegroups.com...

This came up in an earlier thread. On occasion I run into situations
where I'd like to pass arguments from one method to another in an
"argument-per-argument" fashion. Take a look at the following:

> def give
> return [:a,:b,:c]
> end
>
> def give_each
> return *[:a,:b,:c]
> end
>
> def take(*args)
> p *args
> end
>
> take(:a,:b,:c)
> :a
> :b
> :c
>
> take(give)
> [:a, :b, :c]
>
> take(give_each)
> [:a, :b, :c]

I'm interested in the last exmple being like the first. I.e.

> take(give_each)
> :a
> :b
> :c

Which I am calling argument-per-argument passing.
What is the feasibility of this?

How about

take(*give)
take(*give_each)

Note also, that all your give* methods return the same. You can also do

def give2
  return :a,:b,:c
end

def give3
  [:a,:b,:c]
end

Regards

    robert

3

How about

take(*give)
take(*give_each)

Note also, that all your give* methods return the same.

Right, but that's exactly what I don't want to do. I.e. changing the
notation used in passing the arguments to #take. Rather I want a way to
"transfer" the arguments directly into the receiveing method (#take) as
dictated by the return of the giving method (#give).

T.

4

"Trans" <transfire@gmail.com> schrieb im Newsbeitrag news:1106754033.158966.115450@c13g2000cwb.googlegroups.com...

How about

take(*give)
take(*give_each)

Note also, that all your give* methods return the same.

Right, but that's exactly what I don't want to do. I.e. changing the
notation used in passing the arguments to #take. Rather I want a way to
"transfer" the arguments directly into the receiveing method (#take) as
dictated by the return of the giving method (#give).

As it stands you have only these options:

a) Use * at the call (which you don't)

b) make take more flexible (as some methods in the std lib):

def take(*a)
  a = a[0] if a.size == 1 && Enumerable === a[0]
  p a
end

take 1,2,3

[1, 2, 3]
=> nil

take [1,2,3]

[1, 2, 3]
=> nil

Kind regards

    robert