From 870497ca174398c6391ccc11991a809f86eed9f3 Mon Sep 17 00:00:00 2001
From: Thomas Bruderer <apophis@apophis.ch>
Date: Mon, 26 Feb 2024 10:26:53 +0100
Subject: [PATCH] Implements #752 * Implements FindIndexOrNone on List *
 Implements FindLastIndexOrNone on List * with tests

---
 Funcky.Test/Extensions/ListExtensionsTest.cs | 20 ++++++++++++++++
 Funcky/Extensions/ListExtensions.cs          | 24 ++++++++++++++++++++
 Funcky/PublicAPI.Unshipped.txt               |  6 +++++
 3 files changed, 50 insertions(+)

diff --git a/Funcky.Test/Extensions/ListExtensionsTest.cs b/Funcky.Test/Extensions/ListExtensionsTest.cs
index ce56a517..f31dfe15 100644
--- a/Funcky.Test/Extensions/ListExtensionsTest.cs
+++ b/Funcky.Test/Extensions/ListExtensionsTest.cs
@@ -18,4 +18,24 @@ public void GivenAListIndexOfOrNoneReturnsSomeIndexIfTheElementIsInTheList()
 
         FunctionalAssert.Some(2, list.IndexOfOrNone("Epsilon"));
     }
+
+    [Fact]
+    public void GivenAListAndAPredicateFindIndexOrNoneReturnsTheFirstElementMatchingThePredicateInTheGivenInterval()
+    {
+        List<string> list = ["Alpha", "Gamma", "Alien", "Epsilon"];
+
+        FunctionalAssert.Some(0, list.FindIndexOrNone(item => item.StartsWith("Al")));
+        FunctionalAssert.Some(2, list.FindIndexOrNone(2, item => item.StartsWith("Al")));
+        FunctionalAssert.None(list.FindIndexOrNone(3, 1, item => item.StartsWith("Al")));
+    }
+
+    [Fact]
+    public void GivenAListAndAPredicateFindLastIndexOrNoneReturnsTheLastElementMatchingThePredicateInTheGivenInterval()
+    {
+        List<string> list = ["Alpha", "Gamma", "Alien", "Epsilon"];
+
+        FunctionalAssert.Some(2, list.FindLastIndexOrNone(item => item.StartsWith("Al")));
+        FunctionalAssert.Some(0, list.FindLastIndexOrNone(1, item => item.StartsWith("Al")));
+        FunctionalAssert.None(list.FindLastIndexOrNone(3, 1, item => item.StartsWith("Al")));
+    }
 }
diff --git a/Funcky/Extensions/ListExtensions.cs b/Funcky/Extensions/ListExtensions.cs
index 9c7711c3..01a67ef5 100644
--- a/Funcky/Extensions/ListExtensions.cs
+++ b/Funcky/Extensions/ListExtensions.cs
@@ -7,4 +7,28 @@ public static class ListExtensions
     [Pure]
     public static Option<int> IndexOfOrNone<TValue>(this IList<TValue> list, TValue value)
         => MapNotFoundToNone(list.IndexOf(value));
+
+    [Pure]
+    public static Option<int> FindIndexOrNone<TValue>(this List<TValue> list, Predicate<TValue> match)
+        => MapNotFoundToNone(list.FindIndex(match));
+
+    [Pure]
+    public static Option<int> FindIndexOrNone<TValue>(this List<TValue> list, int startIndex, Predicate<TValue> match)
+        => MapNotFoundToNone(list.FindIndex(startIndex, match));
+
+    [Pure]
+    public static Option<int> FindIndexOrNone<TValue>(this List<TValue> list, int startIndex, int count, Predicate<TValue> match)
+        => MapNotFoundToNone(list.FindIndex(startIndex, count, match));
+
+    [Pure]
+    public static Option<int> FindLastIndexOrNone<TValue>(this List<TValue> list, Predicate<TValue> match)
+        => MapNotFoundToNone(list.FindLastIndex(match));
+
+    [Pure]
+    public static Option<int> FindLastIndexOrNone<TValue>(this List<TValue> list, int startIndex, Predicate<TValue> match)
+        => MapNotFoundToNone(list.FindLastIndex(startIndex, match));
+
+    [Pure]
+    public static Option<int> FindLastIndexOrNone<TValue>(this List<TValue> list, int startIndex, int count, Predicate<TValue> match)
+        => MapNotFoundToNone(list.FindLastIndex(startIndex, count, match));
 }
diff --git a/Funcky/PublicAPI.Unshipped.txt b/Funcky/PublicAPI.Unshipped.txt
index 8e1c4602..596cbdff 100644
--- a/Funcky/PublicAPI.Unshipped.txt
+++ b/Funcky/PublicAPI.Unshipped.txt
@@ -12,6 +12,12 @@ Funcky.Monads.Result<TValidResult>.OrElse(System.Func<System.Exception!, Funcky.
 Funcky.UpCast<TResult>
 static Funcky.Extensions.EnumerableExtensions.InspectEmpty<TSource>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Action! inspector) -> System.Collections.Generic.IEnumerable<TSource>!
 static Funcky.Extensions.EnumeratorExtensions.MoveNextOrNone<T>(this System.Collections.Generic.IEnumerator<T>! enumerator) -> Funcky.Monads.Option<T>
+static Funcky.Extensions.ListExtensions.FindIndexOrNone<TValue>(this System.Collections.Generic.List<TValue>! list, int startIndex, int count, System.Predicate<TValue>! match) -> Funcky.Monads.Option<int>
+static Funcky.Extensions.ListExtensions.FindIndexOrNone<TValue>(this System.Collections.Generic.List<TValue>! list, int startIndex, System.Predicate<TValue>! match) -> Funcky.Monads.Option<int>
+static Funcky.Extensions.ListExtensions.FindIndexOrNone<TValue>(this System.Collections.Generic.List<TValue>! list, System.Predicate<TValue>! match) -> Funcky.Monads.Option<int>
+static Funcky.Extensions.ListExtensions.FindLastIndexOrNone<TValue>(this System.Collections.Generic.List<TValue>! list, int startIndex, int count, System.Predicate<TValue>! match) -> Funcky.Monads.Option<int>
+static Funcky.Extensions.ListExtensions.FindLastIndexOrNone<TValue>(this System.Collections.Generic.List<TValue>! list, int startIndex, System.Predicate<TValue>! match) -> Funcky.Monads.Option<int>
+static Funcky.Extensions.ListExtensions.FindLastIndexOrNone<TValue>(this System.Collections.Generic.List<TValue>! list, System.Predicate<TValue>! match) -> Funcky.Monads.Option<int>
 static Funcky.Extensions.ParseExtensions.ParseByteOrNone(this System.ReadOnlySpan<byte> candidate, System.Globalization.NumberStyles style, System.IFormatProvider? provider) -> Funcky.Monads.Option<byte>
 static Funcky.Extensions.ParseExtensions.ParseByteOrNone(this System.ReadOnlySpan<byte> candidate, System.IFormatProvider? provider) -> Funcky.Monads.Option<byte>
 static Funcky.Extensions.ParseExtensions.ParseByteOrNone(this System.ReadOnlySpan<byte> candidate) -> Funcky.Monads.Option<byte>