; test_list.lisp — pairs, lists, predicates, quoting.
; Run:  cat test_list.lisp | ./lisp

'()                              ; => ()
'(1 2 3)                         ; => (1 2 3)
'(a b c)                         ; => (a b c)

(cons 1 2)                       ; => (1 . 2)
(cons 1 '(2 3))                  ; => (1 2 3)
(list 'x 'y 'z)                  ; => (x y z)

(car '(11 22 33))                ; => 11
(cdr '(11 22 33))                ; => (22 33)
(car (cdr '(1 2 3)))             ; => 2
(car (cdr (cdr '(1 2 3))))       ; => 3

(null? '())                      ; => #t
(null? '(1))                     ; => #f
(pair? '(a))                     ; => #t
(pair? 'a)                       ; => #f

(number? 42)                     ; => #t
(number? 'foo)                   ; => #f
(symbol? 'foo)                   ; => #t
(symbol? 1)                      ; => #f
(eq? 'a 'a)                      ; => #t
(eq? 'a 'b)                      ; => #f

; nested literal
'((1 2) (3 4) (5 6))             ; => ((1 2) (3 4) (5 6))
(car '((a b) (c d)))             ; => (a b)