Part V: Parsing Text

This part of the book will teach you about text processing and, specifically, the beginning of parsing text formally. I won't get into all of the different theoretical elements of programming language theory since that is an entire university degree. This is merely the beginning of simple and naive parsing of text in a way that you can use in many programming situations.

Most programmers have a strange relationship with parsing text. The core of all computer programming is parsing, and it's one of the most well understood and formalized aspects of computer science. Parsing data is everywhere in computing. You'll find it in network protocols, compilers, spreadsheets, servers, text editors, graphics renderers, and nearly anything that has to interface with a human or another computer. Even when two computers are sending a fixed binary protocol there is still an aspect of parsing involved despite the lack of text.

I'm going to teach you parsing because it's an easily understood solid technique that produces reliable results. When you're faced with processing some input reliably and giving accurate errors you'll turn to a parser rather than trying to write one by hand. Additionally, once you learn the basics of parsing it becomes easier to learn new programming languages because you can understand their grammar.