Ruby:条件矩阵?有多个条件的情况? [英] Ruby: conditional matrix? case with multiple conditions?

问题描述

在红宝石中，我想知道是否可以执行以下操作:

In ruby, I was wondering if there's a way to do the following:

我基本上有四个可能结果的矩阵:

I have basically a matrix of four possible outcomes:

A is True, B is True
A is True, B is False
A is False, B is True
A is False, B is False

我想以最简洁的红宝石"方式对此进行测试.

I'd like to write a test for this in the cleanest possible "ruby way".

我希望做类似的事情

case[A,B]
  when A && B then ...
  when A && !B then ...
  when !A && B then ...
  when !A && !B then ...
end

...但这不起作用.那么，处理这种情况的最佳方法是什么?

... but that doesn't work. So, what's the best way to handle this kind of situation?

推荐答案

布尔型情况(case中没有表达式，它返回带有 truthy when_expr的第一个分支):

Boolean case (with no expression in the case, it returns the first branch with a truthy when_expr):

result = case
when A && B then ...
when A && !B then ...
when !A && B then ...
when !A && !B then ...
end

匹配大小写(在case中带有表达式，它返回满足谓词when_expr === case_expr的第一个分支):

Matching case (with an expression in the case, it returns the first branch that satisfies the predicate when_expr === case_expr):

result = case [A, B]
when [true, true] then ...
when [true, false] then ...
when [false, true] then ...
when [false, false] then ...
end

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