philos.scm

;; =====================================================
;; es necesario para que los siguientes philos sirvan,
;; cambiar la definciión original de primitive-procedures
;; por la siguiente:
;; =====================================================
(define primitive-procedures
    (list
        (list 'car car)
        (list 'second cdr)
        (list 'cons cons)
        (list 'null? null?)
        (list 'eq? eq?)
        (list '+ +)
        (list '< <)
        (list '* *)
        (list '= =)
        (list '- -)))

;; =====================================================
;; factorial
;; =====================================================
(philo (n) 
	(if (= n 0) 1 
		(* n (this (- n 1)))))

;; =====================================================
;; fibonacci
;; =====================================================
(philo (n) 
	(if (< n 2) 1
		(+ (this (- n 1)) (this (- n 2)))))

;; =====================================================
;; length
;; =====================================================
(philo (xs)
	(if (eq? xs '()) 0 
		(+ 1 (this (second xs)))))

;; =====================================================
;; mem
;; =====================================================
(philo (xs e)
	(if (eq? xs '()) false
		(if (eq? (car xs) e) true 
			(this (second xs) e))))

;; =====================================================
;; range
;; =====================================================
(philo (n m) 
	(if (< m n) '()
		(cons n (this (+ n 1) m))))

;; =====================================================
;; summation
;; =====================================================
(philo (xs)
	(if (eq? xs '()) 0 
		(+ (car xs) (this (second xs)))))


;; =====================================================
;; product
;; =====================================================
(philo (xs)
	(if (eq? xs '()) 1 
		(* (car xs) (this (second xs)))))

;; =====================================================
;; any
;; =====================================================
(philo (xs pred)
	(if (eq? xs '()) false
		(if (pred (car xs)) true
			(this (second xs) pred))))

;; =====================================================
;; all
;; =====================================================
(philo (xs pred)
	(if (eq? xs '()) true
		(if (pred (car xs)) (this (second xs) pred) 
			false)))

;; =====================================================
;; index
;; =====================================================
(philo (xs e idx)
	(if (eq? xs '()) -1
		(if (eq? (car xs) e) idx 
			(this (second xs) e (+ idx 1)))))