Mariner

Mariner

A scientific calculator with an expression parser, history tape, and navigation helpers.

• Launch: python3 apps/Mariner/main.py or Ctrl+Alt+E
• Memory target: ~20 MB
• UI: PySide6 (single file, ~610 lines)

Overview

Mariner is Nautilus' tiny-but-capable calculator. It evaluates full expressions through a hand-written recursive-descent parser — no eval(), no external math engine beyond the stdlib.

Features

• ExpressionEvaluator — a hand-written tokenizer + recursive-descent parser (expr/term/factor/power/atom) over a whitelisted math vocabulary: sin, cos, tan, log, ln, exp, sqrt, fact, gcd, plus the constants pi, e, tau, and phi.
• Full operator support — unary minus, ^ power, ! factorial (gamma fallback), %, and parentheses.
• Live result preview — the result updates as you type.
• History tape — previous results persist to history.json (capped at 200 entries) and are recalled with a click.
• Robust output — handles scientific notation, INF, and NaN gracefully.

Example Expressions

sqrt(2) ^ 10
sin(pi / 6) + cos(tau / 4)
fact(7)
gcd(84, 36)

Implementation Notes

The parser lives entirely inside apps/Mariner/main.py and uses only the Python standard library, keeping the app to ~20 MB of RAM.