如何在 Ruby 中为所有可能的值增加/减少一个字符? [英] How do I increment/decrement a character in Ruby for all possible values?

问题描述

我有一个长度为一个字符的字符串，可以是任何可能的字符值:

I have a string that is one character long and can be any possible character value:

irb(main):001:0> "\x0"
=> "\u0000"

我认为这可能有效:

irb(main):002:0> "\x0" += 1
SyntaxError: (irb):2: syntax error, unexpected tOP_ASGN, expecting $end
"\x0" += 1
        ^            from /opt/rh/ruby193/root/usr/bin/irb:12:in `<main>'

但是，正如你所看到的，它没有.如何增加/减少我的角色?

But, as you can see, it didn't. How can I increment/decrement my character?

Ruby 似乎没有设置为执行此操作.也许我以错误的方式接近这个.我想以 8 位块的形式操作原始数据.我怎样才能最好地完成这种操作?

Ruby doesn't seem to be set up to do this. Maybe I'm approaching this the wrong way. I want to manipulate raw data in terms of 8-bit chunks. How can I best accomplish that sort of operation?

推荐答案

根据可能的值是什么，您可以使用 String#next:

Depending on what the possible values are, you can use String#next:

"\x0".next
# => "\u0001"

或者，更新现有值:

c = "\x0"
c.next!

这可能不是您想要的:

"z".next
# => "aa"

我能想到的增加字符底层代码点的最简单方法是:

The simplest way I can think of to increment a character's underlying codepoint is this:

c = 'z'
c = c.ord.next.chr
# => "{"

递减稍微复杂一些:

c = (c.ord - 1).chr
# => "z"

在这两种情况下，都假设您不会超出 0..255；您可能需要为此添加检查.

In both cases there's the assumption that you won't step outside of 0..255; you may need to add checks for that.

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