mtm-rpn-js/README.md

RPN Virtual Calculator

A browser-friendly RPN calculator built around a small, generic JavaScript API.

Goal

This project defines a reusable RPN calculator engine with:

• a simple stack-based public API
• configurable numeric and UI behavior
• centralized command metadata
• a browser demo that uses the same public API as any consumer code

RPN Virtual Calculator

A browser-friendly RPN calculator built around a small, generic JavaScript API.

Goal

This project provides a reusable Reverse Polish Notation (RPN) calculator engine with:

• a simple stack-based public API
• configurable numeric behavior
• centralized command metadata
• browser demos that use the same public API as any consumer code

Project structure

• src/rpn-calculator.js: calculator engine
• samples/dev/index.html: browser demo
• samples/hp48/index.html: HP48-style browser demo

Main features

• Single JavaScript class: RpnCalculator
• Configurable stack size via maxSize (default: 2048)
• Configurable numeric base via base (default: 10)
• Configurable angle mode via angleMode:
  • deg (default)
  • rad
  • grad
• Optional command filtering through enabledCommands
• Public API limited to generic methods:
  • push(value)
  • pop()
  • clear()
  • swap(index1, index2)
  • remove(index)
  • edit(index)
  • isValidIndex(index)
  • input(command)
  • command(name, ...args)
• inputValue is always stored as a string
• isEditing is exposed as a boolean
• Supported operations are centralized in one dictionary with metadata such as:
  • argCount
  • category
  • aliases
• Supported categories are limited to:
  • Stack
  • Arithmetic
  • Trigonometry

Available constants

• pi
• e

Supported commands

Arithmetic

• add (+)
• sub (-)
• mul (*)
• div (/)
• mod (%)
• pow (^, y^x)
• sqr
• neg
• sqrt
• recip (1/x)
• log
• ln

Trigonometry

• sin
• cos
• tan
• asin
• acos
• atan

Stack

• dup
• drop
• swap
• clear
• enter

Behavior rules

• mod is a percentage operator:
  • a b % => (a * b) / 100
• log uses Math.log10
• ln uses Math.log
• sqrt, asin, acos, log, and ln throw explicit domain errors on invalid input
• Trigonometric behavior depends on angleMode
• In degree mode:
  • sin, cos, tan convert degrees to radians internally
  • asin, acos, atan return degrees
• inputValue remains a string to preserve future support for formats such as hexadecimal input

Basic usage

In a browser

• rpn-calculator.js: calculator engine
• rpn-example.html: example browser interface

Main features

• Single JavaScript class
• Configurable stack size (maxSize, default: 2048)
• Configurable numeric base (base, default: 10)
• Configurable angle mode (angleMode, default: deg)
• Optional command filtering through enabledCommands
• Generic public API centered on:
  • push
  • pop
• clear
  • swap(index1, index2)
  • remove(index)
  • edit(index)
  • isValidIndex(index)
  • input(command)
  • command(name, ...args)
• inputValue is kept as a string to preserve future input formats
• isEditing is exposed as a boolean state
• All supported commands are described in one centralized dictionary
• Supported categories are limited to:
  • Stack
  • Arithmetic
  • Trigonometry

Basic usage

In a browser