mtm-rpn-js/.continue/rules/project.md

Project rules — RPN Virtual Calculator

• Build a browser-friendly RPN calculator as a JavaScript class, preferably in a single file.
• Constructor options: maxSize (default 2048), base (default 10), angleMode (deg default; also rad and grad), enabledCommands.
• Available constants: pi, e.
• Public API is generic only: push, pop, clear, swap(index1, index2), remove(index), edit(index), isValidIndex(index), input(command), and command(name, ...args).
• Expose inputValue as a string and isEditing as a boolean.
• Supported operations are centralized in one dictionary with argCount, category, and aliases.
• Categories are limited to Stack, Arithmetic, and Trigonometry.
• Current commands: add, sub, mul, div, mod, pow, sqr, neg, sqrt, recip, sin, cos, tan, asin, acos, atan, log, ln, dup, drop, swap, clear, enter.
• Aliases: +, -, *, /, %, ^, y^x, 1/x.
• mod is the percentage operator: a b % => (a * b) / 100.
• sqrt, asin, acos, log, and ln must throw clear, explicit domain errors.
• log uses Math.log10; ln uses Math.log.
• Trig functions use degrees in the demo; sin, cos, tan convert to radians, inverse trig returns degrees.
• inputValue stays a string to keep hexadecimal input possible later.
• Example HTML must group buttons by Stack, Arithmetic, and Trigonometry, and call command(...).
• Keep code names, categories, and API identifiers in English.
• Keep this file updated after each project change using the provided editing tools.