Added FirstOrDefault

Local.Tests/Collections/AddShould.cs

@@ -31,7 +31,7 @@ public void AddItems(int itemsCount)
                 Assert.True(vector.Contains(item));
             }
         }
-        
+
         [Theory, MemberData(nameof(ItemsCount))]
         public void AddRangeOfItems(int itemsCount)
         {
@@ -45,7 +45,7 @@ public void AddRangeOfItems(int itemsCount)
                 Assert.True(vector.Contains(item));
             }
         }
-        
+
         [Theory, MemberData(nameof(ItemsCount))]
         public void AddRangeOfItemsCollection(int itemsCount)
         {
@@ -66,13 +66,7 @@ public void AddRangeOfItemsCollection(int itemsCount)
 
         public static TheoryData<int> ItemsCount() => new TheoryData<int>
         {
-            0,
-            1,
-            5,
-            10,
-            20,
-            100,
-            200
+            0, 1, 5, 10, 20, 100, 200
         };
     }
 }

Local.Tests/Collections/ExtensionsShould.cs

@@ -105,7 +105,7 @@ public void ThrowIfCalculateMaxByEmptyVector() => Assert.Throws<InvalidOperation
             var vector = new LocalVector<double>();
             vector.Max();
         });
-        
+
         [Fact]
         public void ThrowIfCalculateMinByEmptyVector() => Assert.Throws<InvalidOperationException>(() =>
         {

Local.Tests/Collections/FirstOrDefaultShould.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Linq;
+using FluentAssertions;
+using Local.Collections;
+using Xunit;
+
+namespace Local.Tests.Collections
+{
+    public class FirstOrDefaultShould : LinqTests
+    {
+        [Theory, MemberData(nameof(Items))]
+        public void FindFirstByPredicate(int[] items)
+        {
+            static bool Predicate(int i) => i == 1;
+
+            var vector = new LocalVector<int>(items);
+
+            vector
+                .FirstOrDefault(Predicate)
+                .Should().Be(items.FirstOrDefault(Predicate));
+        }
+
+        [Theory, MemberData(nameof(Items))]
+        public void FindFirstByPredicateWithArg(int[] items)
+        {
+            const int argument = 1;
+
+            var vector = new LocalVector<int>(items);
+
+            vector
+                .FirstOrDefault((i, arg) => i == arg, argument)
+                .Should().Be(items.FirstOrDefault(i => i == argument));
+        }
+
+        [Fact]
+        public void NotThrowIfNotFoundByPredicate()
+        {
+            new LocalVector<int>()
+                .FirstOrDefault(i => i == 1)
+                .Should().Be(0);
+        }
+
+        [Fact]
+        public void NotThrowIfNotFoundByPredicateWithArg()
+        {
+            const int argument = 1;
+
+            new LocalVector<int>()
+                .FirstOrDefault((i, arg) => i == arg, argument)
+                .Should().Be(0);
+        }
+
+        [Theory, MemberData(nameof(Items))]
+        public void ReturnFirstOrDefaultElement(int[] items)
+        {
+            var vector = new LocalVector<int>(items);
+
+            vector
+                .FirstOrDefault()
+                .Should().Be(items.FirstOrDefault());
+        }
+    }
+}

Local.Tests/Local.Tests.csproj

@@ -9,18 +9,18 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="AutoFixture.Xunit2" Version="4.11.0"/>
-        <PackageReference Include="FluentAssertions" Version="5.10.3"/>
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.6.1"/>
-        <PackageReference Include="Moq" Version="4.14.1"/>
-        <PackageReference Include="xunit" Version="2.4.1"/>
-        <PackageReference Include="xunit.runner.visualstudio" Version="2.4.1"/>
-        <PackageReference Include="coverlet.collector" Version="1.2.1"/>
+        <PackageReference Include="AutoFixture.Xunit2" Version="4.11.0" />
+        <PackageReference Include="FluentAssertions" Version="5.10.3" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.6.1" />
+        <PackageReference Include="Moq" Version="4.14.1" />
+        <PackageReference Include="xunit" Version="2.4.1" />
+        <PackageReference Include="xunit.runner.visualstudio" Version="2.4.1" />
+        <PackageReference Include="coverlet.collector" Version="1.2.1" />
         <PackageReference Include="coverlet.msbuild" Version="2.9.0" />
     </ItemGroup>
 
     <ItemGroup>
-        <ProjectReference Include="..\Local\Local.csproj"/>
+        <ProjectReference Include="..\Local\Local.csproj" />
     </ItemGroup>
 
 </Project>

Local/Collections/LocalVector.Linq.cs

@@ -137,6 +137,43 @@ public readonly T First<TArg>(Func<T, TArg, bool> predicate, TArg arg)
 
         #endregion
 
+        #region FirstOrDefault
+
+        public readonly T FirstOrDefault()
+        {
+            return _length == 0 ? default! : _element0;
+        }
+
+        public readonly T FirstOrDefault(Func<T, bool> predicate)
+        {
+            for (var i = 0; i < _length; i++)
+            {
+                var element = Get(i);
+                if (predicate(element))
+                {
+                    return element;
+                }
+            }
+
+            return default!;
+        }
+
+        public readonly T FirstOrDefault<TArg>(Func<T, TArg, bool> predicate, TArg arg)
+        {
+            for (var i = 0; i < _length; i++)
+            {
+                var element = Get(i);
+                if (predicate(element, arg))
+                {
+                    return element;
+                }
+            }
+
+            return default!;
+        }
+
+        #endregion
+
         public readonly T Last()
         {
             EnsureNotEmpty();

Local/Collections/LocalVector.cs

@@ -205,7 +205,7 @@ public readonly bool Contains(T element, EqualityComparer<T>? comparer = null)
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public readonly Enumerator GetEnumerator() => new Enumerator(in this);
+        public readonly Enumerator GetEnumerator() => new Enumerator(this);
 
         public void Reverse()
         {

Local/Local.csproj

@@ -10,11 +10,11 @@
 
         <Title>Local</Title>
         <Description>Simple collection on stack</Description>
-        <Version>0.8.1</Version>
+        <Version>0.8.2</Version>
         <RepositoryType>git</RepositoryType>
         <RepositoryUrl>git://github.com/teoadal/local</RepositoryUrl>
         <PackageId>Locals</PackageId>
-        <PackageTags>collection;list;performance</PackageTags>
+        <PackageTags>collection;stack;list;performance</PackageTags>
         <PackageProjectUrl>https://github.com/teoadal/local</PackageProjectUrl>
         <PackageLicenseExpression>MIT</PackageLicenseExpression>
         <GeneratePackageOnBuild>true</GeneratePackageOnBuild>