Abacus

Abacus is a small, expressive calculator language for quick experiments and teaching functional programming ideas. It pairs a friendly REPL with pattern-matched functions so you can sketch algorithms without bootstrapping a full Rust project.

Install

Cargo

cargo install abacus

Try It

Run the REPL with abc:

Abacus - Calculator REPL
Type expressions or 'quit' to exit

> rate = 0.0825
> with_tax(amount) = amount * (1 + rate)
> with_tax(24.99)
27.05475
> fib(0) = 0
> fib(1) = 1
> fib(n) = fib(n-1) + fib(n-2)
> fib(10)
55
> odd(n) = n % 2 == 1
> odd(41)
true

Highlights

• Persistent REPL environment with history and an ANSI-colored prompt.
• 64-bit integers, double-precision floats, and booleans with straightforward formatting.
• Arithmetic, comparison, logical, and bitwise operators with predictable precedence.
• Pattern-matched function arms: mix literals and identifiers and the most specific match runs.
• Helpful diagnostics that underline exactly where evaluation failed.

Build From Source

cargo build

License

This project is licensed under the MIT License.