/notepad-based-calculator

A smart calculator using natural language processing

Primary LanguageC#MIT LicenseMIT

notepad-based-calculator

This is a unfinished project, but it is in a state where you can easily reuse it.

The concept

Making an app similar to numi.app, soulver.app and parsify.app, cross-platform using C#.

Current state

The calculator engine is about 100% done. But it remains a few features I wanted to add that I didn't finish.

Feature Example Support
Basic algebra using digits 2 + 3 ✅
Basic algebra using plain words two plus three ✅
Implicit algebra operations 20 (50) ✅
Nested grouped operation (12)3+(1 +2)(3(2))(1 +2)-3 ✅
Binary operations 0.2 >= a fifth ✅
Percentage calculation 10 + 25% ✅
Comments 12 + 3 // anything after "//" is ignored ✅
Headers # Title ✅
Variables my income tax = 25% ✅
Conditions if my income tax > 30% then $123 else $456 ✅
Unit calculation 2km + 25% // should result 2.5 km
2 USD + 2 CAD // should result something like 3.05 USD
3 MB - 2 KB // should result 2.998 MB
Supports length, mass, currencies, area, angle, volume, speed, temperature, date and time, percentage, computer data		 ✅
Function grammars (see detail below) PERCENTAGE of what is NUMERIC
i.e: 25% of what is 50 // should result 200		 ✅
Multilanguage deux plus trois ✅ (partial)
Unit conversion What is 1 USD in EUR
1km in meters
Shouldn't be too complicated to implement using function grammar		 ❌

Please check the unit tests for a complete list of supported scenarios.

Technical details

Overall architecture

  • NotepadBasedCalculator.Api
    This is the public API.

  • NotepadBasedCalculator.Core
    This is core engine. It contains the lexer, parser and generic interpreter.

  • NotepadBasedCalculator.BuiltInPlugins
    Contains all the basic extensions, which includes the components for parsing and interpreting units, basic algebra and binary operation and built-in functions grammars.

  • NotepadBasedCalculator.StandaloneConsoleTestApp This is a console app you can use for testing the calculator manually. Check out how this project is made to understand how to use the calculator.

Screenshot

Extensiblity & Dependency injection

This project uses MEF as primary dependency injection & extensibility framework.

Function grammars

The calculation engine supports various kind of input data: percentage, length, numbers, etc. While this app/library tries to be smart enough to understand input like 25% of what is 50, it isn't smart enough to understand such an input without the help of a pre-defined grammar.

The full grammar for English language can be found here: FunctionDefinition.json

Each function is associated to a MEF extension. The C# implementation automatically binds the class with the function name from the grammar. Here is an example:

  1. Grammar for 25% of what is 50
  2. Implementation in C#

Main third-party dependencies for the calculator engine

How to build and run?

Set up development environment

  • Visual Studio 2022 with Desktop Development workload (Windows)
  • Rider (Windows or MacOS)
  • VS Code with C# extension (MacOS)
  • (Optional) Avalonia UI

Set up repository

  1. Clone the repository
  2. Run init.ps1 (or .sh) to download all the required dependencies.

Build & Debug

  1. Open src/NotepadBasedCalculator.App.sln in Visual Studio or Rider.
  2. Set NotepadBasedCalculator.StandaloneConsoleTestApp as startup project.
  3. F5 😉