Span-based values

src/RustyOptions.Benchmarks/FirstOrNone.cs

@@ -6,14 +6,14 @@ namespace RustyOptions.Benchmarks;
 [GroupBenchmarksBy(BenchmarkLogicalGroupRule.ByCategory)]
 [CategoriesColumn]
 [Config(typeof(Config))]
-public class FirstOrNoneBenchmarks
+public class FirstOrNone
 {
     const int SIZE = 1000;
 
     private readonly int[] intArray;
     private readonly List<int> intList;
 
-    public FirstOrNoneBenchmarks()
+    public FirstOrNone()
     {
         intArray = [.. Enumerable.Range(1, SIZE)];
         intList = [.. intArray];

src/RustyOptions.Benchmarks/LastOrNone.cs

@@ -6,14 +6,14 @@ namespace RustyOptions.Benchmarks;
 [GroupBenchmarksBy(BenchmarkLogicalGroupRule.ByCategory)]
 [CategoriesColumn]
 [Config(typeof(Config))]
-public class LastOrNoneBenchmarks
+public class LastOrNone
 {
     const int SIZE = 1000;
 
     private readonly int[] intArray;
     private readonly List<int> intList;
 
-    public LastOrNoneBenchmarks()
+    public LastOrNone()
     {
         intArray = [.. Enumerable.Range(1, SIZE)];
         intList = [.. intArray];

src/RustyOptions.Benchmarks/NumericOptionValues.cs

@@ -0,0 +1,44 @@
+using BenchmarkDotNet.Attributes;
+
+namespace RustyOptions.Benchmarks;
+
+[Config(typeof(Config))]
+public class NumericOptionValues
+{
+    const int SEED = 10007;
+    const int SIZE = 1000;
+
+    private readonly NumericOption<int>[] intArray;
+    private readonly int[] valuesBuffer;
+
+    public NumericOptionValues()
+    {
+        var rand = new Random(SEED);
+        intArray = [.. Enumerable.Range(1, SIZE)
+            .Select(_ => rand.NextDouble() < 0.45
+                ? rand.Next().SomeNumeric() : NumericOption.None<int>())
+        ];
+        valuesBuffer = new int[intArray.Length];
+    }
+
+    [Benchmark(Baseline = true)]
+    public void EnumerableValues()
+    {
+        int i = 0;
+        foreach (var _ in intArray.AsEnumerable().Values())
+        {
+            i++;
+        }
+    }
+
+    [Benchmark]
+    public void ArrayValues()
+    {
+        int i = 0;
+        int count = intArray.CopyValuesTo(valuesBuffer);
+        foreach (var _ in valuesBuffer.AsSpan(0, count))
+        {
+            i++;
+        }
+    }
+}

src/RustyOptions/NumericOptionExtensions.cs

@@ -3,6 +3,7 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Numerics;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using static System.ArgumentNullException;
 using static RustyOptions.NumericOption;
 
@@ -265,6 +266,85 @@ public static IEnumerable<T> Values<T>(this IEnumerable<NumericOption<T>> self)
         }
     }
 
+    /// <summary>
+    /// Copies the inner values of all <see cref="NumericOption{T}"/> in a span to a destination span,
+    /// returning the number of values copied.
+    /// </summary>
+    /// <typeparam name="T">The type of the numeric option values.</typeparam>
+    /// <param name="self">The source span of numeric options.</param>
+    /// <param name="destination">The destination span to copy the values to.</param>
+    /// <returns>The number of values copied to the destination span.</returns>
+    /// <exception cref="System.IndexOutOfRangeException">
+    /// Thrown if the destination span is too small to hold all the values.
+    /// </exception>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static int CopyValuesTo<T>(this NumericOption<T>[] self, Span<T> destination)
+        where T : struct, INumber<T>
+    {
+        return CopyValuesTo((ReadOnlySpan<NumericOption<T>>)self, destination);
+    }
+
+    /// <summary>
+    /// Copies the inner values of all <see cref="NumericOption{T}"/> in a span to a destination span,
+    /// returning the number of values copied.
+    /// </summary>
+    /// <typeparam name="T">The type of the numeric option values.</typeparam>
+    /// <param name="self">The source span of numeric options.</param>
+    /// <param name="destination">The destination span to copy the values to.</param>
+    /// <returns>The number of values copied to the destination span.</returns>
+    /// <exception cref="System.IndexOutOfRangeException">
+    /// Thrown if the destination span is too small to hold all the values.
+    /// </exception>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static int CopyValuesTo<T>(this List<NumericOption<T>> self, Span<T> destination)
+        where T : struct, INumber<T>
+    {
+        return CollectionsMarshal.AsSpan(self).CopyValuesTo(destination);
+    }
+
+    /// <summary>
+    /// Copies the inner values of all <see cref="NumericOption{T}"/> in a span to a destination span,
+    /// returning the number of values copied.
+    /// </summary>
+    /// <typeparam name="T">The type of the numeric option values.</typeparam>
+    /// <param name="self">The source span of numeric options.</param>
+    /// <param name="destination">The destination span to copy the values to.</param>
+    /// <returns>The number of values copied to the destination span.</returns>
+    /// <exception cref="System.IndexOutOfRangeException">
+    /// Thrown if the destination span is too small to hold all the values.
+    /// </exception>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static int CopyValuesTo<T>(this Span<NumericOption<T>> self, Span<T> destination)
+        where T : struct, INumber<T>
+    {
+        return CopyValuesTo((ReadOnlySpan<NumericOption<T>>)self, destination);
+    }
+
+    /// <summary>
+    /// Copies the inner values of all <see cref="NumericOption{T}"/> in a span to a destination span,
+    /// returning the number of values copied.
+    /// </summary>
+    /// <typeparam name="T">The type of the numeric option values.</typeparam>
+    /// <param name="self">The source span of numeric options.</param>
+    /// <param name="destination">The destination span to copy the values to.</param>
+    /// <returns>The number of values copied to the destination span.</returns>
+    /// <exception cref="System.IndexOutOfRangeException">
+    /// Thrown if the destination span is too small to hold all the values.
+    /// </exception>
+    public static int CopyValuesTo<T>(this ReadOnlySpan<NumericOption<T>> self, Span<T> destination)
+        where T : struct, INumber<T>
+    {
+        int j = 0;
+        for (int i = 0; i < self.Length; i++)
+        {
+            if (self[i].IsSome(out var value))
+            {
+                destination[j++] = value;
+            }
+        }
+        return j;
+    }
+
     /// <summary>
     /// Wraps the given number in a <see cref="NumericOption{T}"/>.
     /// </summary>

src/RustyOptions/OptionCollectionExtensions.cs

@@ -10,7 +10,8 @@ namespace RustyOptions;
 // TODO: test coverage:
 // https://app.codecov.io/github/jtmueller/RustyOptions/blob/users%2Fjtm%2Fcollection-performance/src%2FRustyOptions%2FOptionCollectionExtensions.cs
 // https://app.codecov.io/github/jtmueller/RustyOptions/blob/users%2Fjtm%2Fcollection-performance/src%2FRustyOptions%2FOptionCollectionExtensions.cs
-// TODO: Update README with performance notes.
+// https://app.codecov.io/github/jtmueller/RustyOptions/blob/users%2Fjtm%2Fcollection-performance/src%2FRustyOptions%2FNumericOptionExtensions.cs
+// TODO: Update README with performance notes, JSON breaking change notes.
 
 /// <summary>
 /// Extension methods for using collections with <see cref="Option{T}"/>.
@@ -38,6 +39,85 @@ public static IEnumerable<T> Values<T>(this IEnumerable<Option<T>> self)
         }
     }
 
+    /// <summary>
+    /// Copies the inner values of all <see cref="NumericOption{T}"/> in a span to a destination span,
+    /// returning the number of values copied.
+    /// </summary>
+    /// <typeparam name="T">The type of the numeric option values.</typeparam>
+    /// <param name="self">The source span of numeric options.</param>
+    /// <param name="destination">The destination span to copy the values to.</param>
+    /// <returns>The number of values copied to the destination span.</returns>
+    /// <exception cref="System.IndexOutOfRangeException">
+    /// Thrown if the destination span is too small to hold all the values.
+    /// </exception>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static int CopyValuesTo<T>(this Option<T>[] self, Span<T> destination)
+        where T : struct
+    {
+        return CopyValuesTo((ReadOnlySpan<Option<T>>)self, destination);
+    }
+
+    /// <summary>
+    /// Copies the inner values of all <see cref="NumericOption{T}"/> in a span to a destination span,
+    /// returning the number of values copied.
+    /// </summary>
+    /// <typeparam name="T">The type of the numeric option values.</typeparam>
+    /// <param name="self">The source span of numeric options.</param>
+    /// <param name="destination">The destination span to copy the values to.</param>
+    /// <returns>The number of values copied to the destination span.</returns>
+    /// <exception cref="System.IndexOutOfRangeException">
+    /// Thrown if the destination span is too small to hold all the values.
+    /// </exception>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static int CopyValuesTo<T>(this List<Option<T>> self, Span<T> destination)
+        where T : struct
+    {
+        return CollectionsMarshal.AsSpan(self).CopyValuesTo(destination);
+    }
+
+    /// <summary>
+    /// Copies the inner values of all <see cref="Option{T}"/> in a span to a destination span,
+    /// returning the number of values copied.
+    /// </summary>
+    /// <typeparam name="T">The type of the numeric option values.</typeparam>
+    /// <param name="self">The source span of numeric options.</param>
+    /// <param name="destination">The destination span to copy the values to.</param>
+    /// <returns>The number of values copied to the destination span.</returns>
+    /// <exception cref="System.IndexOutOfRangeException">
+    /// Thrown if the destination span is too small to hold all the values.
+    /// </exception>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static int CopyValuesTo<T>(this Span<Option<T>> self, Span<T> destination)
+        where T : struct
+    {
+        return CopyValuesTo((ReadOnlySpan<Option<T>>)self, destination);
+    }
+
+    /// <summary>
+    /// Copies the inner values of all <see cref="Option{T}"/> in a span to a destination span,
+    /// returning the number of values copied.
+    /// </summary>
+    /// <typeparam name="T">The type of the numeric option values.</typeparam>
+    /// <param name="self">The source span of numeric options.</param>
+    /// <param name="destination">The destination span to copy the values to.</param>
+    /// <returns>The number of values copied to the destination span.</returns>
+    /// <exception cref="System.IndexOutOfRangeException">
+    /// Thrown if the destination span is too small to hold all the values.
+    /// </exception>
+    public static int CopyValuesTo<T>(this ReadOnlySpan<Option<T>> self, Span<T> destination)
+        where T : struct
+    {
+        int j = 0;
+        for (int i = 0; i < self.Length; i++)
+        {
+            if (self[i].IsSome(out var value))
+            {
+                destination[j++] = value;
+            }
+        }
+        return j;
+    }
+
     /// <summary>
     /// Gets the value associated with the given <paramref name="key"/> from the dictionary as an <see cref="Option{T}"/>.
     /// </summary>

src/RustyOptions/ResultCollectionExtensions.cs

@@ -32,6 +32,8 @@ public static IEnumerable<T> Values<T, TErr>(this IEnumerable<Result<T, TErr>> s
         }
     }
 
+    // TODO: Span overload for Values?
+
     /// <summary>
     /// Flattens a sequence of <see cref="Result{T, TErr}"/> into a sequence containing all error values.
     /// Ok results are discarded.

src/RustyOptions/ResultJsonConverter.cs

@@ -78,7 +78,10 @@ public override Result<T, TErr> Read(ref Utf8JsonReader reader, Type typeToConve
             {
                 if (reader.TokenType == JsonTokenType.True)
                 {
-                    if (reader.Read() && reader.TokenType == JsonTokenType.PropertyName && reader.ValueSpan.SequenceEqual("value"u8) && reader.Read())
+                    if (reader.Read() &&
+                        reader.TokenType == JsonTokenType.PropertyName &&
+                        reader.ValueSpan.SequenceEqual("value"u8) &&
+                        reader.Read())
                     {
                         output = Result.Ok<T, TErr>(_valueConverter.Read(ref reader, _valueType, options)!);
                     }
@@ -89,7 +92,10 @@ public override Result<T, TErr> Read(ref Utf8JsonReader reader, Type typeToConve
                 }
                 else if (reader.TokenType == JsonTokenType.False)
                 {
-                    if (reader.Read() && reader.TokenType == JsonTokenType.PropertyName && reader.ValueSpan.SequenceEqual("error"u8) && reader.Read())
+                    if (reader.Read() &&
+                        reader.TokenType == JsonTokenType.PropertyName &&
+                        reader.ValueSpan.SequenceEqual("error"u8) &&
+                        reader.Read())
                     {
                         output = Result.Err<T, TErr>(_errConverter.Read(ref reader, _errType, options)!);
                     }
@@ -107,7 +113,11 @@ public override Result<T, TErr> Read(ref Utf8JsonReader reader, Type typeToConve
             {
                 var value = _valueConverter.Read(ref reader, _valueType, options);
 
-                if (reader.Read() && reader.TokenType == JsonTokenType.PropertyName && reader.ValueSpan.SequenceEqual("ok"u8) && reader.Read() && reader.TokenType == JsonTokenType.True)
+                if (reader.Read() &&
+                    reader.TokenType == JsonTokenType.PropertyName &&
+                    reader.ValueSpan.SequenceEqual("ok"u8) &&
+                    reader.Read() &&
+                    reader.TokenType == JsonTokenType.True)
                 {
                     output = Result.Ok<T, TErr>(value!);
                 }
@@ -120,7 +130,10 @@ public override Result<T, TErr> Read(ref Utf8JsonReader reader, Type typeToConve
             {
                 var err = _errConverter.Read(ref reader, _errType, options);
 
-                if (reader.Read() && reader.TokenType == JsonTokenType.PropertyName && reader.ValueSpan.SequenceEqual("ok"u8) && reader.Read() && reader.TokenType == JsonTokenType.False)
+                if (reader.Read() &&
+                    reader.TokenType == JsonTokenType.PropertyName &&
+                    reader.ValueSpan.SequenceEqual("ok"u8) &&
+                    reader.Read() && reader.TokenType == JsonTokenType.False)
                 {
                     output = Result.Err<T, TErr>(err!);
                 }