3.7 Summary

This has been an introduction to lexical analyzer generators and the process of converting from a regular expression to a minimal DFA, which is the lexical analyzer. This conversion is so complicated that many computer scientists advocate writing a lexical analyzer and then making changes to it for new applications. This works well for applications where the tokens are quite similar.

The process of generating a lexical analyzer has been likened to the compiler process itself:

There are several lexical analyzer generators on the market, making it unlikely that anyone except a compiler tool designer or student in a sadistic instructor's class would ever have to write one.