Extreme Optimization of a Rust Math Expression Parser: From 43 Seconds to 0.98 Seconds

This article details the author's journey in optimizing a Rust-based math expression parser's runtime from 43 seconds to a blazing 0.98 seconds. Through a series of optimizations, including avoiding unnecessary memory allocations, directly processing byte streams, removing the `Peekable` iterator, utilizing multithreading and SIMD instructions, and employing memory-mapped files, a dramatic performance improvement was achieved. The article thoroughly explains the principles and implementation methods of each optimization step, supported by flame graphs and performance data. This is a compelling case study on performance optimization, showcasing meticulous programming and clever use of Rust's features.