CHAPTER 3 — Finite State Transducers

A finite-state automaton does nothing but work its way through a string, accepting or rejecting it. A finite-state transducer (FST) is like an automaton, but it performs various actions as it consumes an input string.

Chapter Topics:

• Definition of a Transducer
• Example Program: converting a string to upper case
• Example Program: implementing trim()
• Example Program: converting an input string to an object

Java's regular expression classes, Pattern and Matcher can be used to do many of the things that hand-coded transducers can do. These classes are explained in future chapters.