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@feighter09
Last active June 4, 2020 13:00
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struct Regex {
let pattern: String
let options: NSRegularExpressionOptions
private var matcher: NSRegularExpression {
return try! NSRegularExpression(pattern: pattern, options: options)
}
init(pattern: String, options: NSRegularExpressionOptions! = nil)
{
self.pattern = pattern
self.options = options ?? []
}
func match(string: String, options: NSMatchingOptions = []) -> Bool
{
let entireRange = NSMakeRange(0, string.characters.count)
let matches = matcher.numberOfMatchesInString(string, options: options, range: entireRange)
return matches > 0
}
}
protocol RegularExpressionMatchable {
func match(regex: Regex) -> Bool
}
extension String: RegularExpressionMatchable {
func match(regex: Regex) -> Bool {
return regex.match(self)
}
}
func ~=<T: RegularExpressionMatchable>(pattern: Regex, matchable: T) -> Bool {
return matchable.match(pattern)
}
// That's it! Have fun using it like so:
switch inputString {
case Regex(pattern: "^4[0-9]{12}(?:[0-9]{3})?$"):
print("It's a Visa card")
case Regex(pattern: "^3[47][0-9]{13}$"):
print("It's American Express")
case Regex(pattern: "^5[1-5][0-9]{14}$"):
print("It's a MasterCard")
case Regex(pattern: "^6(?:011|5[0-9]{2})[0-9]{12}$"):
print("It's a Discover card")
default:
print("ERROR: Unknown card type")
}
switch inputString {
case Regex(pattern: "^clemson(\\su.+)?$", options: NSRegularExpressionOptions.CaseInsensitive):
print("GREAT School!! Awesome Team!")
case Regex(pattern: "^(u.+)?south carolina$", options: NSRegularExpressionOptions.CaseInsensitive):
print("I'm sorry.")
default:
print("Bless your heart.")
}
// Just note that switch cases only execute the first branch that's matched
// The string "heyyo" matches both regular expressions, but only the first branch is executed
switch "heyyo" {
case Regex(pattern: "o$"):
print("ends with o")
case Regex(pattern: "^h"):
print("starts with h")
default:
break
}
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