Rust is a system programming language. A typical task of system programming is processing formal languages. Formal languages are languages specified by well-defined logical rules and used everywhere in computer technology. They can be broadly classified into command, programming, and markup languages.
To process formal languages, the first step is to parse. Parsing means analyzing the grammatical structure of a piece of code to check whether it respects the rules of the grammar it is supposed to use, and then, if the grammar is respected, to generate a data structure that describes the structure of the parsed piece of code, in a way that such code can be further processed.
In this chapter, we will see how to process text written in a formal language, starting from the parsing step and proceeding with several possible outcomes...
