Infix operator for regular expressions.

regexp-helper.swift

// Declare `~>` operator

infix operator ~> {}

// Define the `~>` operator
//
// Example:
// if inputStr ~> "^[a-zA-Z]*$" {
//   println("\(inputStr) only has letters")
// }

public func ~> (input: String, pattern: String) -> Bool {
    return (input as NSString).rangeOfString(pattern, options: .RegularExpressionSearch).location != NSNotFound
}