fpg1503 / regex.swift Goto Github PK

To reproduce:

let regex = Regex(pattern: "(a)|b")!
let match1 = regex.matches("a")     // Captures "a"
let match2 = regex.matches("b")     // fatal error: subscript: subrange extends past String end

If your regular expression has captures that don't participate in the match then NSRegularExpression will give us a {NSNotFound, 0} range for that capture group and this causes a crash in substringWithRange when called from Match.init.