Improving test coverage

Directory.Packages.props

@@ -12,9 +12,9 @@
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
     <PackageVersion Include="NSubstitute" Version="5.3.0" />
     <PackageVersion Include="NSubstitute.Analyzers.CSharp" Version="1.0.17" />
-    <PackageVersion Include="Rnd" Version="10.1.1" />
+    <PackageVersion Include="Rnd" Version="10.2.0" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
     <PackageVersion Include="xunit.v3" Version="3.2.2" />
     <PackageVersion Include="xunit.v3.assert" Version="3.2.2" />
   </ItemGroup>
-</Project>
+</Project>

README.md

@@ -8,10 +8,16 @@ Various monads (including Maybe - see [here](https://en.wikipedia.org/wiki/Monad
 - `Union<T>`
 - `Id<T>` (support for `int`, `uint`, `long`, `ulong` and `Guid` value types)
 - `Maybe<T>` (either: `Some<T>` or `None`)
-- `Result<T>` (either: `Ok<T>` or `Fail`)
+- `Result<T>` (either: `Ok<T>` or `Failure`)
 
 View the [Wiki](https://github.com/bfren/wrap/wiki) for documentation.
 
+## History
+
+Although this library is at v1, it brings together some mature projects I have been working on since 2019. It started with a Result<T> implementation which morphed into Maybe - which reached v10 in November 2025 - and I figured it would be best to have both.
+
+At the same time I was maintaining a StrongId library - which reached v8.5 in November 2024 - to avoid using primitives for Entity IDs. I realised the similarities between Result<T>, Maybe<T> and Id<T> and decided to bring them all together in one library: Wrap.
+
 ## Licence
 
 > [MIT](https://mit.bfren.dev/2019)

Version

@@ -1 +1 @@
-1.1.0-beta.1
+1.1.0-beta.4

src/All/Extensions/Maybe/MaybeExtensions.Audit.cs

@@ -28,7 +28,7 @@ public static Maybe<T> Audit<T>(this Maybe<T> @this, Action? none, Action<T>? so
 	{
 		try
 		{
-			if (@this is Maybe<T>.None && none is not null)
+			if (@this is Maybe<T>.NoneImpl && none is not null)
 			{
 				none();
 			}
@@ -105,7 +105,7 @@ public static async Task<Maybe<T>> AuditAsync<T>(this Task<Maybe<T>> @this, Func
 
 		try
 		{
-			if (result is Maybe<T>.None && none is not null)
+			if (result is Maybe<T>.NoneImpl && none is not null)
 			{
 				await none();
 			}

src/All/Extensions/Maybe/MaybeExtensions.Bind.cs

@@ -18,28 +18,28 @@ public static partial class MaybeExtensions
 	/// <returns><see cref="Maybe{T}"/> object returned by <paramref name="f"/> or <see cref="None"/>.</returns>
 	public static Maybe<TReturn> Bind<T, TReturn>(this Maybe<T> @this, Func<T, Maybe<TReturn>> f) =>
 		M.Match(@this,
-			none: M.None,
+			none: () => M.None,
 			some: f
 		);
 
 	/// <inheritdoc cref="Bind{T, TReturn}(Maybe{T}, Func{T, Maybe{TReturn}})"/>
 	public static Task<Maybe<TReturn>> BindAsync<T, TReturn>(this Maybe<T> @this, Func<T, Task<Maybe<TReturn>>> f) =>
 		M.MatchAsync(@this,
-			none: M.None,
+			none: () => M.None,
 			some: f
 		);
 
 	/// <inheritdoc cref="Bind{T, TReturn}(Maybe{T}, Func{T, Maybe{TReturn}})"/>
 	public static Task<Maybe<TReturn>> BindAsync<T, TReturn>(this Task<Maybe<T>> @this, Func<T, Maybe<TReturn>> f) =>
 		M.MatchAsync(@this,
-			none: M.None,
+			none: () => M.None,
 			some: f
 		);
 
 	/// <inheritdoc cref="Bind{T, TReturn}(Maybe{T}, Func{T, Maybe{TReturn}})"/>
 	public static Task<Maybe<TReturn>> BindAsync<T, TReturn>(this Task<Maybe<T>> @this, Func<T, Task<Maybe<TReturn>>> f) =>
 		M.MatchAsync(@this,
-			none: M.None,
+			none: () => M.None,
 			some: f
 		);
 }

src/All/Extensions/Maybe/MaybeExtensions.IsFalse.cs

@@ -15,14 +15,14 @@ public static partial class MaybeExtensions
 	/// <returns>Whether or not the value of <paramref name="this"/> is <see langword="false"/>.</returns>
 	public static bool IsFalse(this Maybe<bool> @this) =>
 		M.Match(@this,
-			none: false,
-			some: x => x == false
+			none: () => false,
+			some: x => !x
 		);
 
 	/// <inheritdoc cref="IsTrue(Maybe{bool})"/>
 	public static Task<bool> IsFalseAsync(this Task<Maybe<bool>> @this) =>
 		M.MatchAsync(@this,
-			none: false,
-			some: x => x == false
+			none: () => false,
+			some: x => !x
 		);
 }

src/All/Extensions/Maybe/MaybeExtensions.IsTrue.cs

@@ -15,14 +15,14 @@ public static partial class MaybeExtensions
 	/// <returns>Whether or not the value of <paramref name="this"/> is <see langword="true"/>.</returns>
 	public static bool IsTrue(this Maybe<bool> @this) =>
 		M.Match(@this,
-			none: false,
+			none: () => false,
 			some: x => x
 		);
 
 	/// <inheritdoc cref="IsTrue(Maybe{bool})"/>
 	public static Task<bool> IsTrueAsync(this Task<Maybe<bool>> @this) =>
 		M.MatchAsync(@this,
-			none: false,
+			none: () => false,
 			some: x => x
 		);
 }

src/All/Extensions/Maybe/MaybeExtensions.Map.cs

@@ -25,28 +25,28 @@ public static partial class MaybeExtensions
 	/// <returns><see cref="Some{T}"/> object or <see cref="None"/>.</returns>
 	public static Maybe<TReturn> Map<T, TReturn>(this Maybe<T> @this, Func<T, TReturn> f) =>
 		M.Match(@this,
-			none: M.None,
+			none: () => M.None,
 			some: x => M.Wrap(f(x))
 		);
 
 	/// <inheritdoc cref="Map{T, TReturn}(Maybe{T}, Func{T, TReturn})"/>
 	public static Task<Maybe<TReturn>> MapAsync<T, TReturn>(this Maybe<T> @this, Func<T, Task<TReturn>> f) =>
 		M.MatchAsync(@this,
-			none: M.None,
+			none: () => M.None,
 			some: async x => M.Wrap(await f(x))
 		);
 
 	/// <inheritdoc cref="Map{T, TReturn}(Maybe{T}, Func{T, TReturn})"/>
 	public static Task<Maybe<TReturn>> MapAsync<T, TReturn>(this Task<Maybe<T>> @this, Func<T, TReturn> f) =>
 		M.MatchAsync(@this,
-			none: M.None,
+			none: () => M.None,
 			some: x => M.Wrap(f(x))
 		);
 
 	/// <inheritdoc cref="Map{T, TReturn}(Maybe{T}, Func{T, TReturn})"/>
 	public static Task<Maybe<TReturn>> MapAsync<T, TReturn>(this Task<Maybe<T>> @this, Func<T, Task<TReturn>> f) =>
 		M.MatchAsync(@this,
-			none: M.None,
+			none: () => M.None,
 			some: async x => M.Wrap(await f(x))
 		);
 }

src/All/Extensions/Maybe/MaybeExtensions.Match.cs

@@ -28,18 +28,10 @@ public static Task MatchAsync<T>(this Maybe<T> @this, Func<Task> none, Func<T, T
 	public static Task MatchAsync<T>(this Task<Maybe<T>> @this, Func<Task> none, Func<T, Task> some) =>
 		M.MatchAsync(@this, none, some);
 
-	/// <inheritdoc cref="M.Match{T, TReturn}(Maybe{T}, Func{TReturn}, Func{T, TReturn})"/>
-	public static TReturn Match<T, TReturn>(this Maybe<T> @this, TReturn none, Func<T, TReturn> some) =>
-		M.Match(@this, none, some);
-
 	/// <inheritdoc cref="M.Match{T, TReturn}(Maybe{T}, Func{TReturn}, Func{T, TReturn})"/>
 	public static TReturn Match<T, TReturn>(this Maybe<T> @this, Func<TReturn> none, Func<T, TReturn> some) =>
 		M.Match(@this, none, some);
 
-	/// <inheritdoc cref="M.Match{T, TReturn}(Maybe{T}, Func{TReturn}, Func{T, TReturn})"/>
-	public static Task<TReturn> MatchAsync<T, TReturn>(this Maybe<T> @this, TReturn none, Func<T, Task<TReturn>> some) =>
-		M.MatchAsync(@this, none, some);
-
 	/// <inheritdoc cref="M.Match{T, TReturn}(Maybe{T}, Func{TReturn}, Func{T, TReturn})"/>
 	public static Task<TReturn> MatchAsync<T, TReturn>(this Maybe<T> @this, Func<TReturn> none, Func<T, Task<TReturn>> some) =>
 		M.MatchAsync(@this, none, some);
@@ -52,14 +44,6 @@ public static Task<TReturn> MatchAsync<T, TReturn>(this Maybe<T> @this, Func<Tas
 	public static Task<TReturn> MatchAsync<T, TReturn>(this Maybe<T> @this, Func<Task<TReturn>> none, Func<T, Task<TReturn>> some) =>
 		M.MatchAsync(@this, none, some);
 
-	/// <inheritdoc cref="M.Match{T, TReturn}(Maybe{T}, Func{TReturn}, Func{T, TReturn})"/>
-	public static Task<TReturn> MatchAsync<T, TReturn>(this Task<Maybe<T>> @this, TReturn none, Func<T, TReturn> some) =>
-		M.MatchAsync(@this, none, some);
-
-	/// <inheritdoc cref="M.Match{T, TReturn}(Maybe{T}, Func{TReturn}, Func{T, TReturn})"/>
-	public static Task<TReturn> MatchAsync<T, TReturn>(this Task<Maybe<T>> @this, TReturn none, Func<T, Task<TReturn>> some) =>
-		M.MatchAsync(@this, none, some);
-
 	/// <inheritdoc cref="M.Match{T, TReturn}(Maybe{T}, Func{TReturn}, Func{T, TReturn})"/>
 	public static Task<TReturn> MatchAsync<T, TReturn>(this Task<Maybe<T>> @this, Func<TReturn> none, Func<T, TReturn> some) =>
 		M.MatchAsync(@this, none, some);

src/All/Extensions/Maybe/MaybeExtensions.MatchIf.cs

@@ -26,7 +26,7 @@ public static TReturn MatchIf<T, TReturn>(this Maybe<T> @this,
 		Func<T, TReturn> someTrue
 	) =>
 		Match(@this,
-			none: none(),
+			none: none,
 			some: x => predicate(x) switch
 			{
 				false =>

src/All/Extensions/Result/ResultExtensions.Audit.cs

@@ -28,7 +28,7 @@ public static Result<T> Audit<T>(this Result<T> @this, Action<FailureValue>? fai
 	{
 		try
 		{
-			if (@this is Result<T>.Failure y && fail is not null)
+			if (@this is Result<T>.FailureImpl y && fail is not null)
 			{
 				fail(y.Value);
 			}
@@ -111,7 +111,7 @@ public static async Task<Result<T>> AuditAsync<T>(this Task<Result<T>> @this, Fu
 
 		try
 		{
-			if (result is Result<T>.Failure y && fail is not null)
+			if (result is Result<T>.FailureImpl y && fail is not null)
 			{
 				await fail(y.Value);
 			}

src/All/Extensions/Unsafe/UnsafeExtensions.TryFailure.cs

@@ -19,7 +19,7 @@ public static partial class UnsafeExtensions
 	/// <returns>True if <paramref name="this"/> contains a <see cref="Failure"/>.</returns>
 	public static bool TryFailure<T>(this Unsafe<Result<T>, FailureValue, T> @this, out FailureValue value)
 	{
-		if (@this.Value is Result<T>.Failure failure)
+		if (@this.Value is Result<T>.FailureImpl failure)
 		{
 			value = failure.Value;
 			return true;

src/All/Linq/MaybeToMaybe/MaybeToMaybeExtensions.SelectMany.cs

@@ -34,28 +34,28 @@ public static partial class MaybeToMaybeExtensions
 	/// <param name="g">Return map function.</param>
 	public static Maybe<TReturn> SelectMany<T, TInner, TReturn>(this Maybe<T> @this, Func<T, Maybe<TInner>> f, Func<T, TInner, TReturn> g) =>
 		M.Match(@this,
-			none: M.None,
+			none: () => M.None,
 			some: x => f(x).Map(y => g(x, y))
 		);
 
 	/// <inheritdoc cref="SelectMany{T, TInner, TReturn}(Maybe{T}, Func{T, Maybe{TInner}}, Func{T, TInner, TReturn})"/>
 	public static Task<Maybe<TReturn>> SelectMany<T, TInner, TReturn>(this Maybe<T> @this, Func<T, Task<Maybe<TInner>>> f, Func<T, TInner, TReturn> g) =>
 		M.MatchAsync(@this,
-			none: M.None,
+			none: () => M.None,
 			some: x => f(x).MapAsync(y => g(x, y))
 		);
 
 	/// <inheritdoc cref="SelectMany{T, TInner, TReturn}(Maybe{T}, Func{T, Maybe{TInner}}, Func{T, TInner, TReturn})"/>
 	public static Task<Maybe<TReturn>> SelectMany<T, TInner, TReturn>(this Task<Maybe<T>> @this, Func<T, Maybe<TInner>> f, Func<T, TInner, TReturn> g) =>
 		M.MatchAsync(@this,
-			none: M.None,
+			none: () => M.None,
 			some: x => f(x).Map(y => g(x, y))
 		);
 
 	/// <inheritdoc cref="SelectMany{T, TInner, TReturn}(Maybe{T}, Func{T, Maybe{TInner}}, Func{T, TInner, TReturn})"/>
 	public static Task<Maybe<TReturn>> SelectMany<T, TInner, TReturn>(this Task<Maybe<T>> @this, Func<T, Task<Maybe<TInner>>> f, Func<T, TInner, TReturn> g) =>
 		M.MatchAsync(@this,
-			none: M.None,
+			none: () => M.None,
 			some: x => f(x).MapAsync(y => g(x, y))
 		);
 }

src/Common/Functions/F.Format.cs

@@ -0,0 +1,108 @@
+// Wrap: .NET monads.
+// Copyright (c) bfren - licensed under https://mit.bfren.dev/2019
+
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Text.RegularExpressions;
+
+namespace Wrap;
+
+public static partial class F
+{
+	/// <inheritdoc cref="Format{T}(string, T, string?)"/>
+	public static string Format<T>(string formatString, T source) =>
+		Format(formatString, source, null);
+
+	/// <summary>
+	/// Works like string.Format() but with named as well as numbered placeholders.
+	/// <para>Source is Array: values will be inserted in order (regardless of placeholder values).</para>
+	/// <para>Source is Object: property names must match placeholders or they will be left in place.</para>
+	/// </summary>
+	/// <remarks>
+	/// Inspired by http://james.newtonking.com/archive/2008/03/29/formatwith-2-0-string-formatting-with-named-variables,
+	/// (significantly) altered to work without requiring DataBinder.
+	/// </remarks>
+	/// <typeparam name="T">Source type.</typeparam>
+	/// <param name="formatString">String to format.</param>
+	/// <param name="source">Source object to use for template values.</param>
+	/// <param name="replaceIfNullOrEmpty">Returned if <paramref name="formatString"/> or <paramref name="source"/> are null / empty.</param>
+	/// <returns>Formatted string.</returns>
+	public static string Format<T>(string formatString, T source, string? replaceIfNullOrEmpty)
+	{
+		// Return if format string is null or empty
+		if (string.IsNullOrWhiteSpace(formatString))
+		{
+			return replaceIfNullOrEmpty ?? string.Empty;
+		}
+
+		// Return if source is null or an empty array
+		if (source is null)
+		{
+			return replaceIfNullOrEmpty ?? formatString;
+		}
+		else if (source is Array arr && arr.Length == 0)
+		{
+			return replaceIfNullOrEmpty ?? formatString;
+		}
+
+		// Thanks James Newton-King!
+		var regex = TemplateMatcherRegex();
+
+		var values = new List<object>();
+		var replaceIndex = 0; // keeps track of replace loop so we can match named template values with an array source
+		var numberedTemplates = true;
+		var rewrittenFormat = regex.Replace(formatString, (m) =>
+		{
+			var startGroup = m.Groups["start"];
+			var templateGroup = m.Groups["template"];
+			var formatGroup = m.Groups["format"];
+			var endGroup = m.Groups["end"];
+
+			// This is the value inside the braces, e.g. "0" in "{0}" or "A" in "{A}"
+			// Remove any @ symbols from the start - used by Serilog to denote an object format
+			// but breaks the following
+			var template = templateGroup.Value.TrimStart('@');
+			var templateIsNumber = int.TryParse(template, out var templateNumber);
+			numberedTemplates = numberedTemplates && templateIsNumber;
+
+			// Switch on the source type, using variety of methods to get this template's value
+			var flags = BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance;
+			var value = source switch
+			{
+				// Source array - get specific item in array
+				Array arr when numberedTemplates && templateNumber < arr.Length && arr.GetValue(templateNumber) is object val =>
+					val,
+
+				// Source array - get next item in array
+				Array arr when replaceIndex < arr.Length && arr.GetValue(replaceIndex++) is object val =>
+					val,
+
+				// Source object - get matching property value
+				{ } obj when typeof(T).GetProperty(template, flags)?.GetValue(obj) is object val =>
+					val,
+
+				// Nothing matches to use 
+				_ =>
+					$"{{{template}}}"
+			};
+
+			values.Add(value);
+
+			// Recreate format using zero-based string
+			return new string('{', startGroup.Captures.Count)
+				+ (values.Count - 1)
+				+ formatGroup.Value
+				+ new string('}', endGroup.Captures.Count);
+		});
+
+		// Format string
+		var formatted = string.Format(DefaultCulture, rewrittenFormat, [.. values]);
+
+		// If the string still contains any templates, return original format string
+		return regex.IsMatch(formatted) ? formatString : formatted;
+	}
+
+	[GeneratedRegex("(?<start>\\{)+(?<template>[\\w\\.\\[\\]@]+)(?<format>:[^}]+)?(?<end>\\})+", RegexOptions.IgnoreCase | RegexOptions.CultureInvariant)]
+	private static partial Regex TemplateMatcherRegex();
+}

src/Common/IEither.cs

@@ -2,7 +2,6 @@
 // Copyright (c) bfren - licensed under https://mit.bfren.dev/2019
 
 using System;
-using System.Collections.Generic;
 using System.Threading.Tasks;
 
 namespace Wrap;
@@ -23,23 +22,6 @@ public interface IEither<TLeft, TRight>
 	/// the object is <typeparamref name="TLeft"/>.</param>
 	/// <returns>Value of object or provided by <paramref name="getValue"/>.</returns>
 	TRight Unwrap(Func<TLeft, TRight> getValue);
-
-	/// <summary>
-	/// Use enumerator pattern to get <typeparamref name="TRight"/> value.
-	/// </summary>
-	/// <remarks>
-	/// <para>
-	/// For example:
-	/// </para>
-	/// <code>
-	/// foreach (var right in either) {
-	///     // if 'either' is <typeparamref name="TLeft"/>, the loop is empty
-	///     // otherwise 'right' is <typeparamref name="TRight"/><br/>
-	/// }
-	/// </code>
-	/// </remarks>
-	/// <returns>Enumerator containing one value if this is <typeparamref name="TRight"/>.</returns>
-	IEnumerator<TRight> GetEnumerator();
 }
 
 /// <summary>