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Hello all,

here is my first modest attempt at a JAPH. Please note the purely functional style (appart from the necessary side-effect of outputting something ;-) ).

Those who'll recognize the mechanism will probably have a smile in reminescence of that powerful and inefficient way of computing.

If there is some interest I will post an article on the theory behind this (unless it's been done here before).

Please enjoy, comments and suggestions would be greatly appreciated!

Schemer


#!/usr/bin/perl -w
use strict;

# author: guillaume[at]nulko.com

# functions
sub z { shift(); return shift();   }
sub u { return n(\&z);             }
sub d { return n(n(\&z));          }
sub t { return lp(u)->(d);         }
sub f { return um(d)->(d);         }
sub c { return lp(t)->(d);         }
sub a { return shift() + 1;        }
sub w { return chr g(shift())      }
sub g { return shift()->(\&a, 0);  }
sub p { print w(um(shift())->(u)); }


# functions building functions

sub lp { my $a = shift(); 
         return sub { return $a->(\&n,shift())        } }
sub um { my $a = shift(); 
         return sub { return $a->(lp(shift()),\&z)    } }
sub n {  my $a = shift(); 
         return sub { my $b = shift(); 
                      return $b->($a->($b, shift()))  } }


# Lambda, the ultimate...

       $_='p(um(lp(u)->(um(um(t
         )->(t))->(f)))->(d))
          ,p(um(um(lp(u)->(um(
           t)->(f)))->(t))->(t)
            ),p(um(lp(u)->(um(lp
             (u)->(um(d)->(c)))->
              (d)))->(c)),p(um(lp(
               u)->(um(lp(u)->(um(d
                )->(t)))->(f)))->(f)
                 ),p(um(um(d)->(f))->
                  (f)),p(lp(u)->(um(um
                   (um(d)->(t))->(f))->
                    (f))),p(um(um(lp(u)-
                     >(um(d)->(c)))->(d))
                      ->(c)),p(um(lp(u)->(
                       um(um(t)->(t))->(f))
                        )->(t)),p(um(lp(u)->
                         (um(lp(u)->(um(d)->(
                        t))) ->(f))) ->(f)), p
                      (um(um(lp(u)->(um(t)->(f)
                     ))->(d))->(f)),p(lp(u)->(um
                    (um(f)->(c))->(c))),p(um(um(l
                   p(u)->(um( um(d)->(t))->(t)))->
                  (d))->(t))   ,p(um(um(d)->(f))->(
                 f)),p(um(u     m(f)->(f))->(c)),p(l
                p(u)->(um(       um(f)->(c))->(c))),p
               (um(um(lp(         u)->(um(um(d)->(t))-
              >(t)))->(d           ))->(t)),p(um(um(um(
             t)->(t))->             (t))->(f)),p(um(um(d
            )->(f))->(               f)),p(um(um(lp(u)->(
           um(t)->(f)                 ))->(d))->(f)),p(lp(
          u)->(um(um                   (um(d)->(t))->(f))->
         (f))),p(um                     (um(lp(u)->(um(d)->(
        c)))->(t))                       ->(t)),p(lp(u)->(um(
       lp(u)->(um                         (lp(u)->(um(t)->(f))
      )->(f)))->                           (d))),p(lp(u)->(um(u
     m(f)->(c))                             ->(c))),p(um(um(lp(u
    )->(um(um(                               d)->(t))->(t)))->(d)
   )->(t)),p(                                 um(lp(u)->(um(d)->(c
)))->(f)),p(um(                              d)->(c))',s/\s*//g,eval
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In reply to (Almost) Purely Functional JAPH by Schemer

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