asciimath-rs

Parses mathematical (infix) expressions into an Abstract Syntax Tree using Dijkstra's "shunting yard" algorithm.

Simple, bare-bones, and efficient.

Features

evaluation
implicit multiplication
support for variables, both single-letter and word variables
easily-defined custom functions
compiling expressions and evaluating with different sets of variables
f64 output
Baked-in essential functions and constants

High-Level Goals

Ease of use

This means that e.g. passing in variables to expressions and defining custom functions must be possible with minimum knowledge of this library's internals and abstractions. Errors must be helpful and relevant.

Minimalism

Focusing just on mathematical expressions will make it easy for this library to remain slim and deliver superior ergonomics.

Accuracy

Extensive testing and maximum precision must be a part of all the modules to prevent bugs and ensure consistency.

Future

The items below will be considered after ABI stabilization:

Non-mathematical expressions, like strings
More operators (e.g. ternary ? : )
Ability to simplify expressions
Derivatives, incl. second-order and third-order
Integration
Partial differentiation
Vector calculus
Matrices and vector spaces

Non-goals

php-esque abominations like a=func(x) && b=func(y) && 'what'

Motivation

Created for the University of Toronto Mathematical Assessment Tool, to facilitate generation of randomized tests and quizzes which are then automatically graded.