
Security News
pnpm 10.12 Introduces Global Virtual Store and Expanded Version Catalogs
pnpm 10.12.1 introduces a global virtual store for faster installs and new options for managing dependencies with version catalogs.
Mathematical expressions evaluator that supports math functions and enumerators, using only `System`.
Mathematical expressions evaluator that supports math and enumerable functions, using only System
,
from the lexer to the parser with no bizarre regex.
dotnet add package Eval.cs
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");
There are two custom exceptions, catch the rest as general exceptions that have a message
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" |
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 |
Should not happen unless there is a logical problem with this evaluator
Throw like an general Exception that has a message
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
}
);
}
Generates simple math expressions, does not generate functions and parens.
Code to test the lexer, evaluation and exceptions.
FAQs
Mathematical expressions evaluator that supports math functions and enumerators, using only `System`.
We found that eval.cs demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
pnpm 10.12.1 introduces a global virtual store for faster installs and new options for managing dependencies with version catalogs.
Security News
Amaro 1.0 lays the groundwork for stable TypeScript support in Node.js, bringing official .ts loading closer to reality.
Research
A deceptive PyPI package posing as an Instagram growth tool collects user credentials and sends them to third-party bot services.