Re: [boost] De Bruijn Bind (alternate bind syntax) Interest?

Subject: Re: [boost] De Bruijn Bind (alternate bind syntax) Interest?
From: Larry Evans (cppljevans_at_[hidden])
Date: 2010-09-03 14:52:40

On 09/03/10 13:21, Dave Abrahams wrote:
> On Fri, Sep 3, 2010 at 2:03 PM, Larry Evans <cppljevans_at_[hidden]> wrote:
>> What it does do is make implementation of beta reduction easier
> 
> And why would a C++ programmer care about making the implementation of
> beta-reduction easier?
> 
I thought that's essentially what mpl::apply<F,A> does.
Let's see, from:

  http://en.wikipedia.org/wiki/%CE%91_conversion#.CE.B1-conversion

there's:

  Beta-reduction captures the idea of function application.
  Beta-reduction is defined in terms of substitution:
  the beta-reduction of  ((λV.E) E′)  is E[V := E′].

  For example, assuming some encoding of 2, 7, *, we have the
  following β-reductions: ((λn.n*2) 7) → 7*2.

Since, as I mentioned, I had trouble understanding how apply
worked, and the code seems pretty complicated, at least to me,
I was hoping DeBruijn's method would offer simplifications.

OTOH, maybe I'm completely missing something.

-regards,
Larry