Hi all.
There is the idea (in VERY dirty code):
···
--
class Proc
def bound; @bound ||= {} end
def bind(num, val)
bound[num - 1] = val
end
alias :old_arity :arity
def arity
old_arity - bound.size
end
alias :old_call :call
def call(*arg)
bound.to_a.reverse_each{|num, val| arg.insert(num, val)}
old_call(*arg)
end
end
--
Usage:
--
l = lambda{|a,b,c| puts "a=#{a}, b=#{b}, c=#{c}"}
puts l.arity #=>3
l.bind(2, 'b')
puts l.arity #=>2
l.call('a', 'c') #a=a, b=b, c=c
--
Two questions:
1. Does somebody think it is useful?
2. Does somebody already done this in some library?
Thanks.
Victor.
Two questions:
1. Does somebody think it is useful?
Yes, this is called Currying and has been written about a lot.
2. Does somebody already done this in some library?
http://rubymurray.rubyforge.org/
Hope that helps.
James Edward Gray II
···
On May 8, 2006, at 9:07 AM, Victor Shepelev wrote:
There are a few drawbacks to this approach I think, most of which I
forget right now. A probable biggie is that it won't work with yield:
l = lambda { |num,ele| p num, ele }
l.bind(0,10)
[1,2].each &l
# 1
# nil
# 2
# nil
Maybe check out http://rubymurray.rubyforge.org , which does similar
stuff but by wrapping up the proc (still has limitations, but there you
go...)
···
On Mon, 2006-05-08 at 23:07 +0900, Victor Shepelev wrote:
Hi all.
There is the idea (in VERY dirty code):
--
class Proc
def bound; @bound ||= {} end
def bind(num, val)
bound[num - 1] = val
end
alias :old_arity :arity
def arity
old_arity - bound.size
end
alias :old_call :call
def call(*arg)
bound.to_a.reverse_each{|num, val| arg.insert(num, val)}
old_call(*arg)
end
end
--
Ross Bamford - rosco@roscopeco.REMOVE.co.uk
> Two questions:
> 1. Does somebody think it is useful?
Yes, this is called Currying and has been written about a lot.
Oh, I know. The question meant "is this concrete extension would be useful
for this concrete Ruby?" 
> 2. Does somebody already done this in some library?
http://rubymurray.rubyforge.org/
Thanks, just what I've looked for.
Hope that helps.
Yeah, it did.
James Edward Gray II
Victor.
···
From: James Edward Gray II [mailto:james@grayproductions.net]
On May 8, 2006, at 9:07 AM, Victor Shepelev wrote:
*cough* I'd like to quote from the docs at the moment where I lost
the plot...
"You have a hole in your curried subroutine but want to add more spices
after or fill out holes after your first hole."
"Assuming no special spice before the hole, just put a hole in the hole."
···
On May 8, 2006, at 9:07 AM, Victor Shepelev wrote:
Two questions:
1. Does somebody think it is useful?
Yes, this is called Currying and has been written about a lot.
2. Does somebody already done this in some library?
http://rubymurray.rubyforge.org/
> Hi all.
>
> There is the idea (in VERY dirty code):
> --
> class Proc
> def bound; @bound ||= {} end
> def bind(num, val)
> bound[num - 1] = val
> end
>
> alias :old_arity :arity
> def arity
> old_arity - bound.size
> end
>
> alias :old_call :call
> def call(*arg)
> bound.to_a.reverse_each{|num, val| arg.insert(num, val)}
> old_call(*arg)
> end
> end
There are a few drawbacks to this approach I think, most of which I
forget right now. A probable biggie is that it won't work with yield:
Yes, I know (and disclaimer said about "VERY dirty code"). I've just tried
to show raw idea about providing arguments-binding functionality.
RubyMurray which you and James have pointed to, is quite good for this.
Ross Bamford - rosco@roscopeco.REMOVE.co.uk
Victor.
···
From: Ross Bamford [mailto:rossrt@roscopeco.co.uk]
On Mon, 2006-05-08 at 23:07 +0900, Victor Shepelev wrote:
Yeah, in truth it took me longer to figure out what the original Perl
docs were on about than it did to port the library Happily though the
basic usage is pretty simple - just arguments and possibly regular
holes. You wouldn't need to be combining spice and using the other
special spices most of the time.
···
On Mon, 2006-05-08 at 23:43 +0900, benjohn@fysh.org wrote:
> On May 8, 2006, at 9:07 AM, Victor Shepelev wrote:
>
>> Two questions:
>> 1. Does somebody think it is useful?
>
> Yes, this is called Currying and has been written about a lot.
>
>> 2. Does somebody already done this in some library?
>
> http://rubymurray.rubyforge.org/
*cough* I'd like to quote from the docs at the moment where I lost
the plot...
"You have a hole in your curried subroutine but want to add more spices
after or fill out holes after your first hole."
"Assuming no special spice before the hole, just put a hole in the hole."
--
Ross Bamford - rosco@roscopeco.REMOVE.co.uk