Ruby - 用于匹配括号的正则表达式？

Question

我想弄清楚字符串是否正确地关闭了括号。

为此，我使用了以下三个括号对。

[]
()
{}

只要格式正确，括号也可以嵌套。

)([]{} - Does not have properly closed brackets because )( is reverse order

[()] - Does contain properly closed brackets.

我试过使用正则表达式，经过一番摸索，我明白了。

[^\(\[]*(\(.*\))[^\)\]]*

但是，这有一些问题。

只匹配括号不匹配括号

我不明白为什么它与括号不匹配。

在我的示例中，我清楚地在括号前使用了反斜杠。

输入

[] - true
[()] - true (nested brackets but they match properly)
{} - true
}{ - false (brackets are wrong direction)
}[]} - false (brackets are wrong direction)
[[]] - true (nested brackets but they match properly

Answer 1

non_delimiters = /[^(){}\[\]]*/
Paired = /\(#{non_delimiters}\)|\{#{non_delimiters}\}|\[#{non_delimiters}\]/
Delimiter = /[(){}\[\]]/

def balanced? s
  s = s.dup
  s.gsub!(Paired, "".freeze) while s =~ Paired
  s !~ Delimiter
end

balanced?(")([]{}")
# => false
balanced?("[]")
# => true
balanced?("[()]")
# => true
balanced?("{}")
# => true
balanced?("}{")
# => false
balanced?("}[]}")
# => false
balanced?("[[]]")
# => true