;;
;; Type testing.
;;

;; Boolean.
(print "(boolean? true) -> ")       (boolean? true)
(print "(boolean? false) -> ")      (boolean? false)
(print "(boolean? 1) -> ")          (boolean? 1)
(print "(boolean? 5) -> ")          (boolean? 5)
(print "(boolean? \"string\") -> ") (boolean? "string")
(print "(boolean? (+ 1 2 3)) -> ")  (boolean? (+ 1 2 3))
(print "(boolean? (not 1)) -> ")    (boolean? (not 1))

;; Empty list/null.
(print "(nil? true) -> ")       (nil? true)
(print "(nil? false) -> ")      (nil? false)
(print "(nil? 1) -> ")          (nil? 1)
(print "(nil? 5) -> ")          (nil? 5)
(print "(nil? \"string\") -> ") (nil? "string")
(print "(nil? (+ 1 2 3)) -> ")  (nil? (+ 1 2 3))
(print "(nil? (not 1)) -> ")    (nil? (not 1))
(print "(nil? ()) -> ")         (nil? ())

;; String.
(print "(string? true) -> ")       (string? true)
(print "(string? false) -> ")      (string? false)
(print "(string? 1) -> ")          (string? 1)
(print "(string? 5) -> ")          (string? 5)
(print "(string? \"string\") -> ") (string? "string")
(print "(string? (+ 1 2 3)) -> ")  (string? (+ 1 2 3))
(print "(string? (not 1)) -> ")    (string? (not 1))

;; Fixnum.
(print "(fixnum? true) -> ")       (fixnum? true)
(print "(fixnum? false) -> ")      (fixnum? false)
(print "(fixnum? 1) -> ")          (fixnum? 1)
(print "(fixnum? 5) -> ")          (fixnum? 5)
(print "(fixnum? \"string\") -> ") (fixnum? "string")
(print "(fixnum? (+ 1 2 3)) -> ")  (fixnum? (+ 1 2 3))
(print "(fixnum? (not 1)) -> ")    (fixnum? (not 1))

;; Symbol.
(print "(symbol? true) -> ")       (symbol? true)
(print "(symbol? false) -> ")      (symbol? false)
(print "(symbol? 1) -> ")          (symbol? 1)
(print "(symbol? +) -> ")          (symbol? +)
(print "(symbol? \"string\") -> ") (symbol? "string")
(print "(symbol? (+ 1 2 3)) -> ")  (symbol? (+ 1 2 3))
(print "(symbol? (not 1)) -> ")    (symbol? (not 1))
(print "(symbol? 'a) -> ")         (symbol? 'a)
(print "(symbol? 'c) -> ")         (symbol? 'c)

;; Pair.
(print "(pair? false) -> ")        (pair? false)
(print "(pair? 1) -> ")            (pair? 1)
(print "(pair? 5) -> ")            (pair? 5)
(print "(pair? \"string\") -> ")   (pair? "string")
(print "(pair? (+ 1 2 3)) -> ")    (pair? (+ 1 2 3))
(print "(pair? (not 1)) -> ")      (pair? (not 1))
(print "(pair? (cons 1 2)) -> ")   (pair? (cons 1 2))
(print "(pair? (list 1 2 3)) -> ") (pair? (list 1 2 3))

; ;; Procedure.
(print "(procedure? false) -> ")      (procedure? false)
(print "(procedure? 1) -> ")          (procedure? 1)
(print "(procedure? 5) -> ")          (procedure? 5)
(print "(procedure? \"string\") -> ") (procedure? "string")
(print "(procedure? (+ 1 2 3)) -> ")  (procedure? (+ 1 2 3))
(print "(procedure? (not 1)) -> ")    (procedure? (not 1))
(print "(procedure? +) -> ")          (procedure? +)
(print "(procedure? -) -> ")          (procedure? -)
(print "(procedure? procedure?) -> ") (procedure? procedure?)