http://www.perlmonks.org?node_id=997141


in reply to PERLISP meditations

Hello, protist.

This is second time I saw the name 'High Order Perl'. It took me much time to remember the days with common lisp, but I tried anyway. I wonder what does mit classes uses for lisp? It seems different from common lisp...

Tested with clisp.

(defun sum_from_to(TERM from NEXT to) (IF (> from to) 0 (+ (funcall TERM from) (sum_from_to TERM (funcall NEXT from) NEXT to)))) (defun addone (c) (+ 1 c)) (defun self(x) x) (defun square (A) (* A A)) (defun sum-int (A B) (sum_from_to #'self A #'addone B)) (defun sum-sq(A B) (sum_from_to #'square A #'addone B)) (print (sum-int 3 5)) (print (sum-sq 3 5))
And exact same migration from list to perl would work.
#!/usr/bin/perl use strict; use warnings; use feature qw(say); sub sum_from_to{ my ($TERM, $from, $NEXT, $to)=@_; if( $from > $to ){ 0; } else { $TERM->($from) + sum_from_to( $TERM, $NEXT->($from), $NEXT, $to ); } } sub addone{ return 1 + $_[0]} sub self{ return $_[0]} sub square{ return $_[0] * $_[0]} sub sum_int { my($A,$B)=@_; sum_from_to( \&self, $A, \&addone, $B); } sub sum_sq { my($A,$B)=@_; sum_from_to( \&square, $A, \&addone, $B); } say sum_int(3,5); say sum_sq(3,5);
regards.