Investigate ISpanFormattable

specs/Qowaiv.Specs/Chemistry/CAS_Registry_Number_specs.cs

@@ -8,8 +8,7 @@ public class With_domain_logic
     [TestCase("?")]
     public void has_length_zero_for_empty_and_unknown(CasRegistryNumber svo)
         => svo.Length.Should().Be(0);
-
-
+
     [TestCase(5, "73–24–5")]
     [TestCase(7, "7732-18-5")]
     [TestCase(8, "10028-14-5")]

specs/Qowaiv.Specs/Financial/Amount_specs.cs

@@ -91,3 +91,13 @@ public void to_divide_amount_by_amount_as_decimal()
         }
     }
 }
+
+public class Supports_try_format
+{
+    [Test]
+    public void On_interpolated_strings()
+    {
+        FormattableString.Invariant($"{Svo.Amount}").Should().Be("42.17");
+    }
+
+}

specs/Qowaiv.Specs/IFormatable_specs.cs

@@ -0,0 +1,12 @@
+namespace IFormatable_specs;
+
+public class All_SVOs : SvoTypeTest
+{
+    [TestCaseSource(nameof(AllSvos))]
+    public void implement_IFormattable(Type type) => type.Should().Implement(typeof(IFormattable));
+
+#if NET6_0_OR_GREATER
+    [TestCaseSource(nameof(AllSvos))]
+    public void implement_ISpanFormattable(Type type) => type.Should().Implement(typeof(ISpanFormattable));
+#endif
+}

src/Qowaiv/Chemistry/CasRegistryNumber.ToString.cs

@@ -0,0 +1,74 @@
+#pragma warning disable S1210
+// "Equals" and the comparison operators should be overridden when implementing "IComparable"
+// See README.md => Sortable
+
+namespace Qowaiv.Chemistry;
+
+/// <summary>
+/// A CAS Registry Number, is a unique numerical identifier assigned by the
+/// Chemical Abstracts Service (CAS), US to every chemical substance described
+/// in the open scientific literature. It includes all substances described
+/// from 1957 through the present, plus some substances from as far back as the
+/// early 1800's.
+/// </summary>
+#if NET6_0_OR_GREATER
+public readonly partial struct CasRegistryNumber : ISpanFormattable
+#else
+public readonly partial struct CasRegistryNumber : IFormattable
+#endif
+{
+    /// <summary>Returns a formatted <see cref="string" /> that represents the CAS Registry Number.</summary>
+    /// <param name="format">
+    /// The format that this describes the formatting.
+    /// </param>
+    /// <param name="formatProvider">
+    /// The format provider.
+    /// </param>
+    /// <remarks>
+    /// The formats:
+    /// f: as formatted.
+    /// 
+    /// other (not empty) formats are applied on the number (long).
+    /// </remarks>
+    [Pure]
+    public string ToString(string? format, IFormatProvider? formatProvider)
+    {
+        if (StringFormatter.TryApplyCustomFormatter(format, this, formatProvider, out string formatted))
+        {
+            return formatted;
+        }
+        else if (IsEmpty()) return string.Empty;
+        else if (IsUnknown()) return "?";
+        else return format.WithDefault("f") == "f"
+            ? m_Value.ToString(@"#00\-00\-0", formatProvider)
+            : m_Value.ToString(format, formatProvider);
+    }
+#if NET6_0_OR_GREATER
+    /// <inheritdoc />
+    [Pure]
+    public bool TryFormat(Span<char> destination, out int charsWritten, ReadOnlySpan<char> format, IFormatProvider? provider)
+    {
+        if (StringFormatter.TryApplyCustomFormatter(format, this, provider, out string formatted))
+        {
+            return destination.TryWrite(formatted, out charsWritten);
+        }
+        else if (IsEmpty()) return destination.TryWrite(string.Empty, out charsWritten);
+        else if (IsUnknown()) return destination.TryWrite('?', out charsWritten);
+        else return format.WithDefault("f") == "f"
+            ? m_Value.TryFormat(destination, out charsWritten, @"#00\-00\-0", provider)
+            : m_Value.TryFormat(destination, out charsWritten, format, provider);
+    }
+#endif
+    /// <summary>Gets an XML string representation of the CAS Registry Number.</summary>
+    [Pure]
+    private string ToXmlString() => ToString(CultureInfo.InvariantCulture);
+
+    /// <summary>Serializes the CAS Registry Number to a JSON node.</summary>
+    /// <returns>
+    /// The serialized JSON string.
+    /// </returns>
+    [Pure]
+    public string? ToJson() => m_Value == default ? null : ToString(CultureInfo.InvariantCulture);
+
+
+}

src/Qowaiv/Chemistry/CasRegistryNumber.cs

@@ -20,7 +20,7 @@ namespace Qowaiv.Chemistry;
 #if NET5_0_OR_GREATER
 [System.Text.Json.Serialization.JsonConverter(typeof(Json.Chemistry.CasRegistryNumberJsonConverter))]
 #endif
-public readonly partial struct CasRegistryNumber : ISerializable, IXmlSerializable, IFormattable, IEquatable<CasRegistryNumber>, IComparable, IComparable<CasRegistryNumber>
+public readonly partial struct CasRegistryNumber : ISerializable, IXmlSerializable, IEquatable<CasRegistryNumber>, IComparable, IComparable<CasRegistryNumber>
 {
     /// <summary>Represents an empty/not set CAS Registry Number.</summary>
     public static readonly CasRegistryNumber Empty;
@@ -35,44 +35,6 @@ namespace Qowaiv.Chemistry;
     [DebuggerBrowsable(DebuggerBrowsableState.Never)]
     private string DebuggerDisplay => this.DebuggerDisplay("{0:f}");
 
-    /// <summary>Returns a formatted <see cref="string" /> that represents the CAS Registry Number.</summary>
-    /// <param name="format">
-    /// The format that this describes the formatting.
-    /// </param>
-    /// <param name="formatProvider">
-    /// The format provider.
-    /// </param>
-    /// <remarks>
-    /// The formats:
-    /// f: as formatted.
-    /// 
-    /// other (not empty) formats are applied on the number (long).
-    /// </remarks>
-    [Pure]
-    public string ToString(string? format, IFormatProvider? formatProvider)
-    {
-        if (StringFormatter.TryApplyCustomFormatter(format, this, formatProvider, out string formatted))
-        {
-            return formatted;
-        }
-        else if (IsEmpty()) return string.Empty;
-        else if (IsUnknown()) return "?";
-        else return format.WithDefault("f") == "f"
-            ? m_Value.ToString(@"#00\-00\-0", formatProvider)
-            : m_Value.ToString(format, formatProvider);
-    }
-
-    /// <summary>Gets an XML string representation of the CAS Registry Number.</summary>
-    [Pure]
-    private string ToXmlString() => ToString(CultureInfo.InvariantCulture);
-
-    /// <summary>Serializes the CAS Registry Number to a JSON node.</summary>
-    /// <returns>
-    /// The serialized JSON string.
-    /// </returns>
-    [Pure]
-    public string? ToJson() => m_Value == default ? null : ToString(CultureInfo.InvariantCulture);
-
     /// <summary>Deserializes the CAS Registry Number from a JSON number.</summary>
     /// <param name="json">
     /// The JSON number to deserialize.

src/Qowaiv/Date.cs

@@ -9,7 +9,12 @@
 #if NET5_0_OR_GREATER
 [System.Text.Json.Serialization.JsonConverter(typeof(Json.DateJsonConverter))]
 #endif
-public readonly partial struct Date : ISerializable, IXmlSerializable, IFormattable, IEquatable<Date>, IComparable, IComparable<Date>
+public readonly partial struct Date : ISerializable, IXmlSerializable, IEquatable<Date>, IComparable, IComparable<Date>
+#if NET6_0_OR_GREATER
+    , ISpanFormattable
+#else
+    , IFormattable
+#endif
 #if NET7_0_OR_GREATER
     , IIncrementOperators<Date>, IDecrementOperators<Date>
     , IAdditionOperators<Date, TimeSpan, Date>, ISubtractionOperators<Date, TimeSpan, Date>
@@ -412,7 +417,18 @@ public string ToString(string? format, IFormatProvider? formatProvider)
             : m_Value.ToString(format, formatProvider);
     }
 
-    /// <summary>Gets an XML string representation of the @FullName.</summary>
+#if NET6_0_OR_GREATER
+    /// <inheritdoc />
+    public bool TryFormat(Span<char> destination, out int charsWritten, ReadOnlySpan<char> format, IFormatProvider? provider)
+    {
+        format = format.WithDefault("d");
+        return StringFormatter.TryApplyCustomFormatter(format, this, provider, out var formatted)
+            ? destination.TryWrite(formatted, out charsWritten)
+            : m_Value.TryFormat(destination, out charsWritten, format, provider);
+    }
+#endif
+
+    /// <summary>Gets an XML string representation of the date.</summary>
     [Pure]
     private string ToXmlString() => ToString(SerializableFormat, CultureInfo.InvariantCulture);
 

src/Qowaiv/EmailAddressCollection.cs

@@ -333,7 +333,7 @@ public string ToString(string? format, IFormatProvider? formatProvider)
     /// s is not in the correct format.
     /// </exception>
     [Pure]
-    public static EmailAddressCollection Parse(string? s, IFormatProvider formatProvider)
+    public static EmailAddressCollection Parse(string? s, IFormatProvider? formatProvider)
     {
         if (TryParse(s, formatProvider, out EmailAddressCollection val))
         {

src/Qowaiv/Extensions/System.Span.cs

@@ -0,0 +1,48 @@
+#if NET6_0_OR_GREATER
+namespace System;
+
+/// <summary>Extensions on <see cref="Span{T}"/>.</summary>
+internal static class QowaivSpanExtensions
+{
+    /// <summary>Tries to write a nullable <see cref="string"/> to a <see cref="Span{T}"/>&lt;<see cref="char"/>&gt;.</summary>
+    [Pure]
+    public static bool TryWrite(this Span<char> span, string? value, out int charsWritten)
+    {
+        if (value is { Length: > 0 })
+        {
+            if (value.TryCopyTo(span))
+            {
+                charsWritten = value.Length;
+                return true;
+            }
+            else
+            {
+                charsWritten = 0;
+                return false;
+            }
+        }
+        else
+        {
+            charsWritten = 0;
+            return true;
+        }
+    }
+
+    /// <summary>Tries to write a <see cref="char"/> to a <see cref="Span{T}"/>&lt;<see cref="char"/>&gt;.</summary>
+    [Pure]
+    public static bool TryWrite(this Span<char> span, char ch, out int charsWritten)
+    {
+        if (span.Length != 0)
+        {
+            span.Fill(ch);
+            charsWritten = 1;
+            return true;
+        }
+        else
+        {
+            charsWritten = 0;
+            return false;
+        }
+    }
+}
+#endif

src/Qowaiv/Extensions/System.String.cs

@@ -66,6 +66,15 @@ public static string ToTitleCase(this string str, IFormatProvider provider)
     internal static string WithDefault(this string? str, string @default = "")
         => str is { Length: > 0 } ? str : @default;
 
+#if NET6_0_OR_GREATER
+    /// <summary>Returns the provided default if <see cref="string.IsNullOrEmpty(string)"/>,
+    /// otherwise the string value.
+    /// </summary>
+    [Pure]
+    internal static ReadOnlySpan<char> WithDefault(this ReadOnlySpan<char> str, ReadOnlySpan<char> @default)
+        => str.IsEmpty ? @default : str;
+#endif
+
     [Pure]
     internal static string Unify(this string? str) => str.Buffer().Unify();
 

src/Qowaiv/Financial/Amount.cs

@@ -12,6 +12,9 @@ namespace Qowaiv.Financial;
 [System.Text.Json.Serialization.JsonConverter(typeof(Json.Financial.AmountJsonConverter))]
 #endif
 public readonly partial struct Amount : ISerializable, IXmlSerializable, IFormattable, IEquatable<Amount>, IComparable, IComparable<Amount>
+#if NET6_0_OR_GREATER
+    , ISpanFormattable
+#endif
 #if NET7_0_OR_GREATER
     , IIncrementOperators<Amount>, IDecrementOperators<Amount>
     , IUnaryPlusOperators<Amount, Amount>, IUnaryNegationOperators<Amount, Amount>
@@ -401,11 +404,19 @@ namespace Qowaiv.Financial;
     /// The format provider.
     /// </param>
     [Pure]
-    public string ToString(string? format, IFormatProvider? formatProvider) 
+    public string ToString(string? format, IFormatProvider? formatProvider)
         => StringFormatter.TryApplyCustomFormatter(format, this, formatProvider, out string formatted)
         ? formatted
         : m_Value.ToString(format, Money.GetNumberFormatInfo(formatProvider));
 
+#if NET6_0_OR_GREATER
+    /// <inheritdoc />
+    public bool TryFormat(Span<char> destination, out int charsWritten, ReadOnlySpan<char> format, IFormatProvider? provider)
+        => StringFormatter.TryApplyCustomFormatter(format, this, provider, out var formatted)
+        ? destination.TryWrite(formatted, out charsWritten)
+        : m_Value.TryFormat(destination, out charsWritten, format, Money.GetNumberFormatInfo(provider));
+#endif
+
     /// <summary>Gets an XML string representation of the amount.</summary>
     [Pure]
     private string ToXmlString() => ToString(CultureInfo.InvariantCulture);

src/Qowaiv/Formatting/StringFormatter.cs

@@ -1,4 +1,7 @@
-namespace Qowaiv.Formatting;
+using Microsoft.VisualBasic;
+using System.ComponentModel;
+
+namespace Qowaiv.Formatting;
 
 /// <summary>A string formatter class.</summary>
 public static class StringFormatter
@@ -128,6 +131,27 @@ public static bool TryApplyCustomFormatter(string? format, object obj, IFormatPr
         }
     }
 
+#if NET6_0_OR_GREATER
+    /// <summary>Tries to apply the custom formatter to format the object.</summary>
+    /// <param name="format">
+    /// The format to apply
+    /// </param>
+    /// <param name="obj">
+    /// The object to format.
+    /// </param>
+    /// <param name="formatProvider">
+    /// The format provider.
+    /// </param>
+    /// <param name="formatted">
+    /// The formatted result.
+    /// </param>
+    /// <returns>
+    /// True, if the format provider supports custom formatting, otherwise false.
+    /// </returns>
+    public static bool TryApplyCustomFormatter(ReadOnlySpan<char> format, object obj, IFormatProvider? formatProvider, out string formatted)
+        => TryApplyCustomFormatter(format.ToString(), obj, formatProvider, out formatted);
+#endif
+
     /// <summary>Replaces diacritic characters by non diacritic ones.</summary>
     /// <param name="str">
     /// The string to remove the diacritics from.

src/Qowaiv/Generated/EmailAddress.generated.cs

@@ -96,6 +96,15 @@ public partial struct EmailAddress : IFormattable
     public string ToString(IFormatProvider? provider) => ToString(format: null, provider);
 }
 
+#if NET6_0_OR_GREATER
+public partial struct EmailAddress : ISpanFormattable
+{
+    /// <inheritdoc />
+    public bool TryFormat(Span<char> destination, out int charsWritten, ReadOnlySpan<char> format, IFormatProvider? provider)
+        => destination.TryWrite(ToString(format.ToString(), provider), out charsWritten);
+}
+#endif
+
 public partial struct EmailAddress : ISerializable
 {
     /// <summary>Initializes a new instance of the email address based on the serialization info.</summary>

src/Qowaiv/Generated/Financial/BusinessIdentifierCode.generated.cs

@@ -96,6 +96,15 @@ public partial struct BusinessIdentifierCode : IFormattable
     public string ToString(IFormatProvider? provider) => ToString(format: null, provider);
 }
 
+#if NET6_0_OR_GREATER
+public partial struct BusinessIdentifierCode : ISpanFormattable
+{
+    /// <inheritdoc />
+    public bool TryFormat(Span<char> destination, out int charsWritten, ReadOnlySpan<char> format, IFormatProvider? provider)
+        => destination.TryWrite(ToString(format.ToString(), provider), out charsWritten);
+}
+#endif
+
 public partial struct BusinessIdentifierCode : ISerializable
 {
     /// <summary>Initializes a new instance of the BIC based on the serialization info.</summary>

src/Qowaiv/Generated/Financial/InternationalBankAccountNumber.generated.cs

@@ -96,6 +96,15 @@ public partial struct InternationalBankAccountNumber : IFormattable
     public string ToString(IFormatProvider? provider) => ToString(format: null, provider);
 }
 
+#if NET6_0_OR_GREATER
+public partial struct InternationalBankAccountNumber : ISpanFormattable
+{
+    /// <inheritdoc />
+    public bool TryFormat(Span<char> destination, out int charsWritten, ReadOnlySpan<char> format, IFormatProvider? provider)
+        => destination.TryWrite(ToString(format.ToString(), provider), out charsWritten);
+}
+#endif
+
 public partial struct InternationalBankAccountNumber : ISerializable
 {
     /// <summary>Initializes a new instance of the IBAN based on the serialization info.</summary>