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.
• Keep code names, categories, and API identifiers in English.
• Use only read-only / generic public API methods: 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.
• Constructor options:
  • maxSize (default 2048)
  • base (default 10)
  • angleMode (deg default; also rad and grad)
  • enabledCommands
• Available constants: pi, e.
• Supported operations must be centralized in one dictionary containing at least:
  • argCount
  • category
  • aliases
• Allowed categories are limited to: Stack, Arithmetic, and Trigonometry.

Supported commands

• 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

Behavior rules

• 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
• Trigonometric functions must support deg, rad, and grad
• In the browser demo, degrees are the default angle mode
• inputValue must remain a string to preserve future hexadecimal input support

Demo rules

• The browser demo lives under samples/dev/
• samples/dev/index.html is the demo entry page
• samples/dev/index.css contains the calculator visual theme
• samples/dev/index.js contains demo-side presentation helpers and UI logic
• The demo UI must expose:
  • a stack display
  • a main display
  • a visible angle mode indicator
  • an angle mode selector for deg, rad, and grad
• The demo may present user-facing labels such as +, −, ×, ÷, y^x, 1/x, and x² while still using English command identifiers internally
• The example HTML must group buttons by Stack, Arithmetic, and Trigonometry
• The example HTML must call command(...) for actions
• Keyboard support in the demo should remain consistent with the displayed help text

File references

• samples/dev/index.html references src/rpn-calculator.js as the calculator engine used by the demo
• Keep the demo aligned with the public calculator API exposed by src/rpn-calculator.js

Maintenance

• Keep this file updated after each project change using the provided editing tools.
• When changing the demo UI or calculator API, update these rules so they continue to match the current project behavior.