Parsely

Parse equations with Typst.

Parsely provides tools to parse Typst equations into structured syntax trees using user-specified grammars.

Supports prefix/infix/postfix operators, precedence, associativity and recursive pattern matching allowing complex mathematical expressions to be parsed.

Usage examples

Self-contained usage examples can be found in the manual:

• drawing expression trees from equations (using CeTZ)
• performing engineering calculations with units (using Pariman)
• turning equations into functions for plotting (using Lilaq)

Minimal example

#import "@preview/parsely:0.1.1"

From the equation $A x + b$ obtain the abstract syntax tree

(head: "add", args: ((head: "mul", args: ($A$, $x$)), $b$))

using the main function parsely.parse(eqn, grammar) where the grammar

#let grammar = (
  add: (infix: $+$, prec: 1, assoc: true),
  mul: (infix: $$, prec: 2, assoc: true),
)

defines the syntax of the operators that form the nodes in the tree.

Change log

v0.1.1

• Add operator guards and rewrite rules.
• Improve documentation.
• Fix usage examples.
• Improve the default parsely.common.arithmetic grammar.

v0.1.0

• Initial concept.