https://github.com/igor-tkachev/linq.expressions.deconstruct

Pattern matching support for System.Linq.Expressions.
https://github.com/igor-tkachev/linq.expressions.deconstruct

Last synced: over 1 year ago
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Pattern matching support for System.Linq.Expressions.

• Host: GitHub
• URL: https://github.com/igor-tkachev/linq.expressions.deconstruct
• Owner: igor-tkachev
• License: mit
• Created: 2019-08-01T01:07:48.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2024-04-15T19:06:25.000Z (about 2 years ago)
• Last Synced: 2024-10-12T02:48:24.979Z (over 1 year ago)
• Language: C#
• Homepage:
• Size: 143 KB
• Stars: 9
• Watchers: 3
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.TXT

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README

          
# Linq.Expressions.Deconstruct

[![Build status](https://ci.appveyor.com/api/projects/status/j4dym9acp0i9aau0/branch/master?svg=true)](https://ci.appveyor.com/project/igor-tkachev/linq-expressions-deconstruct/branch/master) [![NuGet Version and Downloads count](https://buildstats.info/nuget/Linq.Expressions.Deconstruct)](https://www.nuget.org/packages/Linq.Expressions.Deconstruct/)

```c#

[Test]

public void MatchTest()

{

    Expression> f = i => i * 2;

    switch (f.ToExpr())

    {

        case Lambda(Multiply(Parameter("i") p1, Constant(2)), [("i") p2])

            when p1 == p2 :

            Console.WriteLine("Pattern Matched!");

            break;

        default:

            Console.WriteLine(f);

            Assert.Fail();

            break;

    }

}

```

```c#

[Test]

public void ConstantFoldingTest()

{

    Expression> f = i => i * 0 + 0 + i + 10 * (i * 0 + 2);

    var f1 = f.TransformEx(ex => ex switch

    {

        Multiply(Constant(0) e,   _)               => e,               // 0 * e => 0

        Multiply(_,               Constant(0) e)   => e,               // e * 0 => 0

        Multiply(Constant(1),     var e)           => e,               // 1 * e => e

        Multiply(var e,           Constant(1))     => e,               // e * 1 => e

        Divide  (Constant(0) e,   _)               => e,               // 0 / e => 0

        Divide  (var e,           Constant(1))     => e,               // e / 1 => e

        Add     (Constant(0),     var e)           => e,               // 0 + e => e

        Add     (var e,           Constant(0))     => e,               // e + 0 => e

        Subtract(Constant(0),     var e)           => Negate(e),       // 0 - e => -e

        Subtract(var e,           Constant(0))     => e,               // e - 0 => e

        Multiply(Constant(int x), Constant(int y)) => Constant(x * y), // x * y => e

        Divide  (Constant(int x), Constant(int y)) => Constant(x / y), // x / y => e

        Add     (Constant(int x), Constant(int y)) => Constant(x + y), // x + y => e

        Subtract(Constant(int x), Constant(int y)) => Constant(x - y), // x - y => e

        _                                          => ex

    });

    Assert.IsTrue(f1.EqualsTo(i => i + 20));

}

```