Summary

In this chapter, we built a command-line application from scratch in Rust, without using any third-party libraries, to compute the value of the arithmetic expressions. We covered many basic concepts in Rust, including data types, how to model and design an application domain with Rust data structures, how to split code across modules and integrate them, how to structure code within a module as functions, how to expose module functions to other modules, how to do pattern matching for elegant and safe code, how to add functionality to structs and enums, how to implement traits and annotate lifetimes, how to design and propagate custom error types, how to box types to make data sizes predictable for the compiler, how to construct a recursive node tree and navigate it, how to write code that recursively evaluates an expression, and how to specify lifetime parameters for structs.

Congratulations if you successfully followed along and got some working code! If you had any difficulties...