lisp格式字符串,它使用一个参数并在多个指令位置打印

Question

我想做这个

(format nil "One occurence of ~X , another one: ~X , and yet another one: ~X" #\some-char)

有没有X格式指令可以做到这一点？

Answer 1

找到它:它 ~:*告诉lisp重用最后一个参数.就像在一个地方倒退论点一样.

有关整个说明的段落,请参阅:http://www.gigamonkeys.com/book/a-few-format-recipes.html(它位于页面底部附近)

所以它变成了

(format nil "One occurence of ~C , another one: ~:*~C , and yet another one: ~:*~C" #\a)
=> "One occurence of a , another one: a , and yet another one: a"