format - 使用变量作为格式指令的前缀参数

Question

我需要在它之前打印具有可变数量空格的东西。例如，如果我需要在文本前打印 5 个空格，我会这样做:

(format T "%5T My Text")
Output:     My Text

代替 5，我可以使用变量并能够将值传递给它吗？我正在寻找的是这样的:

(format T "%(~d)T My Text" 5)
output:     My Text

Answer 1

尝试

(format T "~vT My Text" 5)

见 22.3 Formatted Output :

In place of a prefix parameter to a directive, V (or v) can be used. In this case, format takes an argument from args as a parameter to the directive. The argument should be an integer or character. If the arg used by a V parameter is nil, the effect is as if the parameter had been omitted. # can be used in place of a prefix parameter; it represents the number of args remaining to be processed. When used within a recursive format, in the context of ~? or ~{, the # prefix parameter represents the number of format arguments remaining within the recursive call.