https://github.com/gsscoder/exprengine

.NET expression evaluator engine
https://github.com/gsscoder/exprengine

api csharp dot-net dotnet-core evaluator expression library

Last synced: 27 days ago
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.NET expression evaluator engine

• Host: GitHub
• URL: https://github.com/gsscoder/exprengine
• Owner: gsscoder
• License: mit
• Created: 2012-12-27T06:27:37.000Z (almost 12 years ago)
• Default Branch: master
• Last Pushed: 2020-02-22T19:58:24.000Z (over 4 years ago)
• Last Synced: 2024-09-28T22:40:54.303Z (about 1 month ago)
• Topics: api, csharp, dot-net, dotnet-core, evaluator, expression, library
• Language: C#
• Homepage:
• Size: 3.51 MB
• Stars: 21
• Watchers: 5
• Forks: 5
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: ChangeLog
  • License: LICENSE

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README

        
# Expression Engine

This project is a simple mathematical expression parser written in C#. It's the refactoring of a previous project and uses an AST-evaluation algorithm. You can use built-in or bind your functions and variables to global scope.

## Documentation

Documentation is available in the project [Wiki](https://github.com/gsscoder/exprengine/wiki).

## Targets

- .NET Standard 2.0

- .NET Framework 4.0, 4.5, 4.6.1

## At a glance:

```csharp

var contex = new Context()

  .SetVariable("G", 6.67428D)

  .SetVariable("earth_mass", Evaluate.As("5.97219 * pow(10,24)")) // 5.97219E+24 kg

  .SetVariable("lunar_mass", Evaluate.As("7.34767309 * pow(10,22)")) // 7.34767309E+22 kg

  .SetVariable("perigee_dist", 356700000D) // moon-earth distance at perigee in m

  .SetFunction("calc_force", (object[] args) => ((double) args[0] * (double) args[1]) / Math.Pow((double) args[2], 2));

var result = contex.EvaluateAs("G * calc_force(earth_mass, lunar_mass, perigee_dist)"); // 2.3018745174107073E+31

bool isGCorrect = contex.EvaluateAs("G == 6.67428");

```

## REPL

```sh

$ dotnet build -c release

...

$ ./artifacts/ExpressionEngine.REPL/Release/netcoreapp3.1/xeval --help

xeval 1.0.0

Copyright © Giacomo Stelluti Scala, 2012-2020

This is free software. You may redistribute copies of it under the terms of

the MIT License .

Usage: xeval [EXPRESSION]

       xeval --interactive

       xeval -f [FILENAME]

       cmdx | xeval

  -f, --filename       Input text file to be evaluated.

  -i, --interactive    Run in interactive mode.

  -q, --quiet          Print only the evaluation results.

  -v, --version        Print version information and exit.

  --help               Display this help screen.

```