From: Joe Van Dyk <joevandyk@...>
Date: 2005-07-26T13:26:18+09:00
Subject: Re: Lisp on Lines

On 7/25/05, Ara.T.Howard <Ara.T.Howard@noaa.gov> wrote:
> On Tue, 26 Jul 2005, Devin Mullins wrote:
> 
> > zak.wilson@gmail.com wrote:
> >
> >> This looks like first class functions to me:
> >>
> >> def accgen (n)
> >>  lambda {|i| n += i }
> >> end
> >>
> >> foo = accgen(5)
> >> foo.call(5) # returns 10
> >> foo.call(5) # returns 15
> >>
> >> accgen function borrowed from http://www.paulgraham.com/accgen.html
> >>
> > Perhaps we need a new term. According to Google, "First class hooberglobbers"
> > seems to mean hooberglobbers can be assigned to variables, parameters, and
> > return values, and then, though the assignee, can be manipulated in all the
> > ways that hooberglobbers can be manipulated. Under this definition, yes, Ruby
> > has first class functions.
> >
> > I have a stricter definition. Let's call it "patrician hooberglobbers."
> > Patrician hooberglobbers, to me, have the additional quality that the syntax
> > for manipulating a hooberglobber is the same whether it is referred to
> > statically or by evaluation/substitution (as through a variable, or return
> > value of a function call). In this sense, Ruby has patrician classes:
> >
> > a = String.new
> > b = String
> > c = b.new
> >
> > However, while Lisp, Python (from the examples I've seen), and Unlambda have
> > patrician functions, Ruby does not. I can think of two simple enough reasons
> > for this:
> >
> > 1. Because Ruby has a "poetry mode," there is no way to refer to a function
> > by reference -- simply referring to it invokes it. The closest you can get is
> > to refer to the Symbol representing its name, or to create a Method object,
> > which really just wraps an invocation of the method inside a class.
> 
>    harp:~ > irb
>    irb(main):001:0> a = lambda{ p 42 }
>    => #<Proc:0xb755d848@(irb):1>
> 
>    irb(main):002:0> a ()
>    42
>    => nil
> 
>    irb(main):003:0> a()
>    42
>    => nil
> 
>    irb(main):004:0> b = a
>    => #<Proc:0xb755d848@(irb):1>
>    irb(main):005:0> b()
>    42
>    => nil
> 
>    harp:~ > ruby -v
>    ruby 1.9.0 (2005-05-16) [i686-linux]
> 
>    harp:~ > irb -v
>    irb 0.9.5(05/04/13)

Is 1.9 going to be 2.0 when it's released?