nanoexpr

Rust · no_std · Parser · C ABI · 2026 - present

Heap-free mathematical expression parser and evaluator for embedded Rust with bounded stack usage.

Overview

A no_std mathematical expression evaluator for microcontrollers that does not allocate heap memory. Its parser evaluates expressions directly without a heap-allocated syntax tree, limits nesting depth, and reports precise errors. It supports several numeric representations, variables, and functions. Source and documentation.

Engineering approach

The parser evaluates expressions without building a heap-allocated syntax tree, making it relevant to MCUs with tight memory limits. Bounded nesting, error reporting and Rust/C interfaces make it reusable outside its original context.

Scope and limitations

Designed as a reusable library independent of one application. Refer to the upstream repository for current APIs, examples, platform constraints and supported versions.

Explore the project

Source repository, documentation or official result ↗

Related work: Xila · getargs-derive