Home Blog Monday. June 30, 2025 - 44 mins Optimizing a Math Expression Parser in Rust Table of contents Baseline implementation (43.1 s) How it works Parser Example: (1 + 2) - 3 It works! But we can do better Optimizations for speed and memory Optimization 1: Do not allocate a Vector when tokenizing (43.1 s → 6.45 s, –85% improvement) Optimization 2: Zero allocations — parse directly from the input bytes (6.45 s → 3.68 s, –43% improvement) Optimization 3: Do not use Peekable (3.68...