m.rkt

#lang racket

(define (matrix m n)
  (if (= 1 m)
      (for/list ((a (in-range 1 (+ n 1))))
        (list a))
      (let ((downstream (matrix (- m 1) n)))
        (for*/list ((a (in-range 1 (+ n 1)))
                    (b (in-list downstream)))
          (cons a b)))))
(length (matrix 10 6))

m.scm

;#lang racket

(define null '())

(define (matrix m n)
  (if (= 1 m)
      (let loop ([a 1])
	(if (= a (+ n 1))
	    null
	    (cons (list a) (loop (+ a 1)))))
      
      ;(for/list ((a (in-range 1 (+ n 1))))
      ;  (list a))
      (let ((downstream (matrix (- m 1) n)))
	(let loop ([a 1])
	  (if (= a (+ n 1))
	      null
	      (append (map (lambda (b) (cons a b)) downstream)
		      (loop (+ a 1))))))))
	
        ;(for*/list ((a (in-range 1 (+ n 1)))
        ;            (b (in-list downstream)))
        ;  (cons a b)))))
(display (length (matrix 10 6)))
(newline)

timings

[samth@huor:/tmp/guile-2.9.5 plt] time ./meta/guile -s ~/m.scm
60466176

real	0m12.291s
user	0m31.301s
sys	0m5.041s
[samth@huor:/tmp/guile-2.9.5 plt] time ./meta/guile -s ~/m.scm
60466176

real	0m12.383s
user	0m26.433s
sys	0m4.695s
[samth@huor:/tmp/guile-2.9.5 plt] time racketcs ~/m.rkt 
60466176

real	0m11.185s
user	0m10.204s
sys	0m0.981s
[samth@huor:/tmp/guile-2.9.5 plt] time racketcs ~/m.rkt 
60466176

real	0m11.197s
user	0m10.233s
sys	0m0.964s
[samth@huor:/tmp/guile-2.9.5 plt] time r ~/m.rkt
60466176

real	0m17.153s
user	0m14.234s
sys	0m2.927s
[samth@huor:/tmp/guile-2.9.5 plt] time r ~/m.rkt
60466176

real	0m17.340s
user	0m14.604s
sys	0m2.745s