Merge pull request #33 from jdmartinez/feature/complete-unit-type

feature/complete-unit-type

Author: jdmartinez

src/Functional/Functional.csproj

@@ -13,4 +13,8 @@
     <RepositoryUrl>https://github.com/jdmartinez/Functional</RepositoryUrl>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.10" />
+  </ItemGroup>
+
 </Project>

src/Functional/Option/Extensions/IQueryable/Option.FirstOrNone.cs

@@ -5,8 +5,8 @@ namespace Functional;
 public static partial class OptionExtensions
 {
     public static Option<T> FirstOrNone<T>(this IQueryable<T> query)
-        => query.FirstOrDefault() ?? Option<T>.None;
+        => query.FirstOrDefault();
 
     public static Option<T> FirstOrNone<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate)
-        => query.FirstOrDefault(predicate) ?? Option<T>.None;
+        => query.FirstOrDefault(predicate);
 }

src/Functional/Option/Extensions/IQueryable/Option.FirstOrNoneAsync.cs

@@ -0,0 +1,17 @@
+using System.Linq.Expressions;
+using Microsoft.EntityFrameworkCore;
+
+namespace Functional;
+
+public static partial class OptionExtensions
+{
+    public static async Task<Option<T>> FirstOrNoneAsync<T>(this IQueryable<T> source, CancellationToken cancellationToken = default)
+        => await source.FirstOrDefaultAsync(cancellationToken);
+
+    public static async Task<Option<T>> FirstOrNoneAsync<T>(
+        this IQueryable<T> source,
+        Expression<Func<T, bool>> predicate, 
+        CancellationToken cancellationToken = default)
+        => await source.FirstOrDefaultAsync(predicate, cancellationToken);
+
+}

src/Functional/Option/Extensions/IQueryable/Option.SingleOrNone.cs

@@ -0,0 +1,13 @@
+using System.Linq.Expressions;
+
+namespace Functional;
+
+public static partial class OptionExtensions
+{
+    public static Option<T> SingleOrNone<T>(this IQueryable<T> query)
+        => query.SingleOrDefault();
+
+    public static Option<T> SingleOrNone<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate)
+        => query
+            .SingleOrDefault(predicate);
+}

src/Functional/Option/Extensions/IQueryable/Option.SingleOrNoneAsync.cs

@@ -0,0 +1,17 @@
+using System.Linq.Expressions;
+using Microsoft.EntityFrameworkCore;
+
+namespace Functional;
+
+public static partial class OptionExtensions
+{
+    public static async Task<Option<T>> SingleOrNoneAsync<T>(this IQueryable<T> source, CancellationToken cancellationToken = default)
+        => await source.SingleOrDefaultAsync(cancellationToken);
+
+    public static async Task<Option<T>> SingleOrNoneAsync<T>(
+        this IQueryable<T> source,
+        Expression<Func<T, bool>> predicate, 
+        CancellationToken cancellationToken = default)
+        => await source.FirstOrDefaultAsync(predicate, cancellationToken);
+
+}

src/Functional/Option/Option.cs

@@ -31,8 +31,11 @@ private Option(T? value)
 
     public static implicit operator Option<T>(Option _) => None;
 
-    public static implicit operator Option<T>(T value)
-        => value is Option<T> opt
-            ? opt
-            : Some(value);
+    public static implicit operator Option<T>(T? value)
+        => value switch
+        {
+            Option<T> opt => opt,
+            not null => Some(value),
+            _ => None
+        };
 }

src/Functional/Unit/Unit.cs

@@ -1,10 +1,12 @@
 namespace Functional;
 
-public readonly record struct Unit
+public readonly record struct Unit : IComparable<Unit>
 {
     public static readonly Unit Default = new();
 
     public override int GetHashCode() => 0;
 
     public override string ToString() => "Unit:()";
+
+    public int CompareTo(Unit other) => 0;
 }

src/Functional/Validator/Extensions/ValidationResult.AsSpan.cs

@@ -0,0 +1,9 @@
+namespace Functional;
+
+public static partial class ValidationResultExtensions
+{
+    public static ReadOnlySpan<Error> AsSpan<T>(this ValidationResult<T> result)
+        => result.IsSuccess
+            ? []
+            : new(result.Errors.ToArray());
+}

src/Functional/Validator/Extensions/ValidationResult.Match.cs

@@ -0,0 +1,14 @@
+namespace Functional;
+
+public static partial class ValidationResultExtensions
+{
+    public static TReturn Match<T, TReturn>(this ValidationResult<T> result, Func<TReturn> onSuccess, Func<TReturn> onFailure)
+        => result.IsSuccess
+            ? onSuccess()
+            : onFailure();
+
+    public static TReturn Match<T, TReturn>(this ValidationResult<T> result, Func<T, TReturn> onSuccess, Func<IEnumerable<Error>, TReturn> onFailure)
+        => result.IsSuccess
+            ? onSuccess(result.Value)
+            : onFailure(result.Errors);
+}

src/Functional/Validator/ValidationResult.cs

@@ -0,0 +1,37 @@
+namespace Functional;
+
+public record ValidationResult<T>
+{
+    private readonly List<Error> _errors = [];
+
+    public T Value { get; } = default!;
+
+    public IReadOnlyList<Error> Errors => _errors.AsReadOnly();
+
+    public bool IsSuccess => _errors.Count == 0;
+
+    public bool IsFailure => !IsSuccess;
+
+    private ValidationResult(T value, IEnumerable<Error> errors)
+    {
+        Value = value;
+        _errors.AddRange(errors.Where(e => e != Error.None));
+    }
+
+    public static ValidationResult<T> Success(T value) => new(value, []);
+
+    public static ValidationResult<T> Failure(T value, IEnumerable<Error> errors)
+    {
+        if (errors.Any(e => e == Error.None))
+            throw new InvalidOperationException(nameof(errors));
+
+        return new ValidationResult<T>(value, errors);
+    }
+
+    public static implicit operator ValidationResult<T>(T value) => Success(value);
+
+    public override int GetHashCode()
+        => IsSuccess
+            ? 0
+            : HashCode.Combine(_errors);
+}