プログラム言語論メモ (2024/11/18)

code:el

(defun fact-recursive (n)

(cond ((< n '1) '1)

('t (* n (fact-recursive (- n '1))))

(defun fact-tail-merge (n &optional queue)

(cond ((< n '1) (fact-execute-queue queue '1))

(defun fact-execute-queue (queue x)

(cond ((consp queue) (fact-execute-queue (cdr queue) (funcall (car queue) x)))

('t x)))

code:lisp

(list (car '(a b)) (car '(c d)))

→ (a c)

`(,(car '(a b)) ,(car '(c d)))

→ (a c)

`(a ,(car '(b c)) c)

→ (a b c)

code:el

(reverse '(1 2))

→ (2 1)

`(,(reverse '(1 2)))

→ ((2 1))

`(,@(reverse '(1 2)) )

→ (2 1)

`(a ,@(reverse '(1 2)) b)

→ (a 2 1 b)

(defmacro first (x) `(car ,x))

→ first

(macroexpand '(first '(a b c)))

(car '(a b c))

(first '(a b c))

→ a