Eval.cs
0.4.0
See the version list below for details.
dotnet add package Eval.cs --version 0.4.0
NuGet\Install-Package Eval.cs -Version 0.4.0
<PackageReference Include="Eval.cs" Version="0.4.0" />
paket add Eval.cs --version 0.4.0
#r "nuget: Eval.cs, 0.4.0"
// Install Eval.cs as a Cake Addin #addin nuget:?package=Eval.cs&version=0.4.0 // Install Eval.cs as a Cake Tool #tool nuget:?package=Eval.cs&version=0.4.0
Eval.cs
Mathematical expressions evaluator that supports math and enumerable functions, using only System
,
from the lexer to the parser with no bizarre regex.
Install
dotnet add package Eval.cs
Usage
using System;
using Eval;
// csharp prefixes can be omitted and lower cased
Console.WriteLine(Evaluator.Evaluate("-2 + pi - Ceiling(3.2)"));
// Everything is called like functions
Console.WriteLine(Evaluator.Evaluate("IEnumerable.Average(2, 3, 5)"));
Console.WriteLine(Evaluator.Evaluate("pow(-average(2, 3, 5), -5)"));
Console.WriteLine(Evaluator.Evaluate("19e-11 /- 12");
Console.WriteLine(Evaluator.Evaluate("last(4, last(1, 2), 5)");
Console.WriteLine(Evaluator.Evaluate("921.315 * -20.93 % 34.567");
Console.WriteLine(Evaluator.Evaluate(" 9>>3 /+ 1.2");
Exceptions
There are two custom exceptions, catch the rest as general exceptions that have a message
InvalidExpressionException
Means that the passed string is not a valid expression
Type | Property | Description |
---|---|---|
string |
Src |
the expression |
int |
Offset |
the offset before the error, specialy useful for pointing where the error has happened |
int |
Length |
the length of the wrong value or function |
string |
Message |
the cause of the exception, eg: "Closing unexsistent paren" |
ArgumentAmountException
Means that the wrong of arguments was passed to a function
Type | Property | Description |
---|---|---|
string |
Src |
same as InvalidExpressionException |
int |
Offset |
same as InvalidExpressionException |
int |
Length |
same as InvalidExpressionException |
string |
Message |
the message: $"Function () expects Expected arguments but received Received " |
string |
Function |
name of the failed function |
int |
Expected |
expected amount of arguments |
int |
Received |
received amount of arguments |
UnexpectedEvaluationException
Should not happen unless there is a logical problem with this evaluator
Throw like an general Exception that has a message
Example
A text based exception
pow() expects 2 arguments but received 3
Math.Pow(1, 2, 3) - 4
^~~~~~~~~~~~~~~~^
using Eval;
using System;
static string ErrorMsg(string message, string src, int offset, int length)
{
if (length < 1)
{
return $"{message}";
}
var marker = new string(' ', offset);
if (length == 1)
{
marker += "^";
}
else if (length == 2)
{
marker += "^^";
}
else if (length > 2)
{
marker += $"^{new('~', length - 2)}^";
}
return $"{message}\n{src}\n{marker}";
}
try
{
var result = Evaluator.Evaluate("Math.Pow(1, 2, 3) - 4");
}
catch (Exception e)
{
Console.WriteLine(
e switch
{
InvalidExpressionException ie => ErrorMsg(ie.Message, ie.Src, ie.Offset, ie.Length),
ArgumentAmountException ae => ErrorMsg(ae.Message, ae.Src, ae.Offset, ae.Length),
_ => e.Message
}
);
}
ExprGen
Generates simple math expressions, does not generate functions and parens.
EvalTest
Code to test the lexer, evaluation and exceptions.
Product | Versions Compatible and additional computed target framework versions. |
---|---|
.NET | net7.0 is compatible. net7.0-android was computed. net7.0-ios was computed. net7.0-maccatalyst was computed. net7.0-macos was computed. net7.0-tvos was computed. net7.0-windows was computed. net8.0 was computed. net8.0-android was computed. net8.0-browser was computed. net8.0-ios was computed. net8.0-maccatalyst was computed. net8.0-macos was computed. net8.0-tvos was computed. net8.0-windows was computed. |
-
net7.0
- No dependencies.
NuGet packages
This package is not used by any NuGet packages.
GitHub repositories
This package is not used by any popular GitHub repositories.
Version | Downloads | Last updated |
---|---|---|
0.10.0 | 84 | 6/9/2024 |
0.9.0 | 80 | 6/6/2024 |
0.8.0 | 79 | 6/3/2024 |
0.7.1 | 92 | 5/30/2024 |
0.7.0 | 89 | 5/29/2024 |
0.6.0 | 88 | 5/27/2024 |
0.5.0 | 152 | 9/4/2023 |
0.4.0 | 147 | 6/6/2023 |
0.3.0 | 125 | 6/4/2023 |
0.2.1 | 137 | 5/28/2023 |
0.2.0 | 115 | 5/27/2023 |
0.1.3 | 148 | 4/30/2023 |
0.1.2 | 153 | 4/26/2023 |
0.1.0 | 145 | 4/26/2023 |
0.0.2 | 153 | 4/25/2023 |
0.0.1 | 143 | 4/25/2023 |