calc_rust

A strongly typed, spreadsheet-style expression engine — currency, tonnage, percentages, dates, durations, and tables are distinct first-class types, not just decorated numbers. A Rust rewrite of Attica-oss/calc, usable as a CLI, a Rust library, or a Python extension module.

Install

CLI (from source, requires Rust):

cargo install --path . --bin calc_rust

Python:

pip install calc-rust

CLI usage

calc_rust '$5.00 * 3'          # $15.00  (currency)
calc_rust                      # start the REPL
calc_table new "item:text, price:currency, qty:int" table.json

Python usage

import calc_rust

calc_rust.evaluate("$5.00 * 3")          # Currency($15.00)
calc_rust.evaluate("1 + 2 * 3")          # 7

calc = calc_rust.Calculator()
calc.set("price", calc_rust.Currency("12.50"))
calc.eval("price * 3")                   # Currency($37.50)

Currency, duration, and complex-number results come back as dedicated classes (.amount, .months/.days/.seconds, .real/.imag); numbers, text, booleans, and dates/times come back as native Python types.

Notebook

A marimo notebook backed by this engine lives in notebook/, replicating the expression-editor and table-builder workflow of the original Python project's notebook:

pip install -e '.[notebook]'
maturin develop --release
marimo edit notebook/calc_notebook.py

Development

cargo test                     # engine tests
maturin develop --release      # build + install the Python extension

License

MIT — see LICENSE.