Regular Expressions
This is a simple library to deal with regular expressions using derivatives, based on Brzozowski's 1964 paper "Derivatives of regular expressions".
Performance Notice
This is a non-optimized implementation and is focused purely on correctness, so the raw complexity is exponential.
Usage
It provides integration with the language, allowing the following:
val lowerCase: RE = 'a' range 'z'
val upperCase: RE = 'A' range 'Z'
val vowels: RE = "aeiou".oneOf
val digit: RE = '0' range '9'
val nonZeroDigit: RE = '1' range '9'
val unsigned: RE = "0" | (nonZeroDigit ~ digit.*)
val integer: RE = ("-" | "+").? ~ unsigned
val alphaNum = lowerCase | upperCase | digitMatching is as simple as:
integer matches "1234"
email matches "foor@bar.baz"