从字符串创建输入流

Created: November-22, 2018

宏 WITH-INPUT-FROM-STRING 可用于从字符串生成流。

(with-input-from-string (str "Foobar")
  (loop for i from 0
        for char = (read-char str nil nil)
        while char
        do (format t "~d: ~a~%" i char)))
; 0: F
; 1: o
; 2: o
; 3: b
; 4: a
; 5: r
;=> NIL

同样可以使用 MAKE-STRING-INPUT-STREAM 手动完成。

(let ((str (make-string-input-stream "Foobar")))
  (loop for i from 0
        for char = (read-char str nil nil)
        while char
        do (format t "~d: ~a~%" i char)))