feat: More overloads for AppendFormat

Author: linkdotnet

CHANGELOG.md

@@ -6,6 +6,10 @@ All notable changes to **ValueStringBuilder** will be documented in this file. T
 
 ## [Unreleased]
 
+### Added
+
+- Two more overloads for `AppendFormat` for up to 5 generic arguments
+
 ## [1.11.5] - 2023-01-09
 
 ### Added

src/LinkDotNet.StringBuilder/ValueStringBuilder.AppendFormat.cs

@@ -197,6 +197,168 @@ public void AppendFormat<T1, T2, T3>(
         }
     }
 
+    /// <summary>
+    /// Appends the format string to the given <see cref="ValueStringBuilder"/> instance.
+    /// </summary>
+    /// <param name="format">Format string.</param>
+    /// <param name="arg1">Argument for <c>{0}</c>.</param>
+    /// <param name="arg2">Argument for <c>{1}</c>.</param>
+    /// <param name="arg3">Argument for <c>{2}</c>.</param>
+    /// <param name="arg4">Argument for <c>{3}</c>.</param>
+    /// <typeparam name="T1">Any type for <param name="arg1"></param>.</typeparam>
+    /// <typeparam name="T2">Any type for <param name="arg2"></param>.</typeparam>
+    /// <typeparam name="T3">Any type for <param name="arg3"></param>.</typeparam>
+    /// <typeparam name="T4">Any type for <param name="arg4"></param>.</typeparam>
+    /// <remarks>
+    /// The current version does not allow for a custom format.
+    /// So: <code>AppendFormat("{0:00}")</code> is not allowed and will result in an exception.
+    /// </remarks>
+    [MethodImpl(MethodImplOptions.AggressiveOptimization)]
+    public void AppendFormat<T1, T2, T3, T4>(
+        [StringSyntax(StringSyntaxAttribute.CompositeFormat)] ReadOnlySpan<char> format,
+        T1 arg1,
+        T2 arg2,
+        T3 arg3,
+        T4 arg4)
+    {
+        var formatIndex = 0;
+        var start = 0;
+        while (formatIndex < format.Length)
+        {
+            var c = format[formatIndex];
+            if (c == '{')
+            {
+                var endIndex = format[(formatIndex + 1)..].IndexOf('}');
+                if (endIndex == -1)
+                {
+                    Append(format);
+                    return;
+                }
+
+                if (start != formatIndex)
+                {
+                    Append(format[start..formatIndex]);
+                }
+
+                var placeholder = format.Slice(formatIndex, endIndex + 2);
+
+                var index = GetValidArgumentIndex(placeholder, 3);
+
+                switch (index)
+                {
+                    case 0:
+                        AppendInternal(arg1);
+                        break;
+                    case 1:
+                        AppendInternal(arg2);
+                        break;
+                    case 2:
+                        AppendInternal(arg3);
+                        break;
+                    case 3:
+                        AppendInternal(arg4);
+                        break;
+                }
+
+                formatIndex += endIndex + 2;
+                start = formatIndex;
+            }
+            else
+            {
+                formatIndex++;
+            }
+        }
+
+        if (start != formatIndex)
+        {
+            Append(format[start..formatIndex]);
+        }
+    }
+
+    /// <summary>
+    /// Appends the format string to the given <see cref="ValueStringBuilder"/> instance.
+    /// </summary>
+    /// <param name="format">Format string.</param>
+    /// <param name="arg1">Argument for <c>{0}</c>.</param>
+    /// <param name="arg2">Argument for <c>{1}</c>.</param>
+    /// <param name="arg3">Argument for <c>{2}</c>.</param>
+    /// <param name="arg4">Argument for <c>{3}</c>.</param>
+    /// <param name="arg5">Argument for <c>{4}</c>.</param>
+    /// <typeparam name="T1">Any type for <param name="arg1"></param>.</typeparam>
+    /// <typeparam name="T2">Any type for <param name="arg2"></param>.</typeparam>
+    /// <typeparam name="T3">Any type for <param name="arg3"></param>.</typeparam>
+    /// <typeparam name="T4">Any type for <param name="arg4"></param>.</typeparam>
+    /// <typeparam name="T5">Any type for <param name="arg5"></param>.</typeparam>
+    /// <remarks>
+    /// The current version does not allow for a custom format.
+    /// So: <code>AppendFormat("{0:00}")</code> is not allowed and will result in an exception.
+    /// </remarks>
+    [MethodImpl(MethodImplOptions.AggressiveOptimization)]
+    public void AppendFormat<T1, T2, T3, T4, T5>(
+        [StringSyntax(StringSyntaxAttribute.CompositeFormat)] ReadOnlySpan<char> format,
+        T1 arg1,
+        T2 arg2,
+        T3 arg3,
+        T4 arg4,
+        T5 arg5)
+    {
+        var formatIndex = 0;
+        var start = 0;
+        while (formatIndex < format.Length)
+        {
+            var c = format[formatIndex];
+            if (c == '{')
+            {
+                var endIndex = format[(formatIndex + 1)..].IndexOf('}');
+                if (endIndex == -1)
+                {
+                    Append(format);
+                    return;
+                }
+
+                if (start != formatIndex)
+                {
+                    Append(format[start..formatIndex]);
+                }
+
+                var placeholder = format.Slice(formatIndex, endIndex + 2);
+
+                var index = GetValidArgumentIndex(placeholder, 4);
+
+                switch (index)
+                {
+                    case 0:
+                        AppendInternal(arg1);
+                        break;
+                    case 1:
+                        AppendInternal(arg2);
+                        break;
+                    case 2:
+                        AppendInternal(arg3);
+                        break;
+                    case 3:
+                        AppendInternal(arg4);
+                        break;
+                    case 4:
+                        AppendInternal(arg5);
+                        break;
+                }
+
+                formatIndex += endIndex + 2;
+                start = formatIndex;
+            }
+            else
+            {
+                formatIndex++;
+            }
+        }
+
+        if (start != formatIndex)
+        {
+            Append(format[start..formatIndex]);
+        }
+    }
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static int GetValidArgumentIndex(ReadOnlySpan<char> placeholder, int allowedRange)
     {

tests/LinkDotNet.StringBuilder.UnitTests/ValueStringBuilder.AppendFormat.Tests.cs

@@ -66,4 +66,32 @@ public void ShouldAppendFormatWithThreeArguments(string format, object arg1, obj
 
         builder.ToString().Should().Be(expected);
     }
+
+    [Theory]
+    [InlineData("Hello {0} {1} {2} {3}", 2, 3, 4, 5, "Hello 2 3 4 5")]
+    [InlineData("{0}{0}{1}{2}{3}", 2, 3, 3, 2, "22332")]
+    [InlineData("{0} World", "Hello", "", "", "", "Hello World")]
+    [InlineData("Hello World", "2", "", "", "", "Hello World")]
+    public void ShouldAppendFormatWithFourArguments(string format, object arg1, object arg2, object arg3, object arg4, string expected)
+    {
+        using var builder = new ValueStringBuilder();
+
+        builder.AppendFormat(format, arg1, arg2, arg3, arg4);
+
+        builder.ToString().Should().Be(expected);
+    }
+
+    [Theory]
+    [InlineData("Hello {0} {1} {2} {3} {4}", 2, 3, 4, 5, 3, "Hello 2 3 4 5 3")]
+    [InlineData("{0}{0}{1}{2}{3}{4}", 2, 3, 3, 2, 2, "223322")]
+    [InlineData("{0} World", "Hello", "", "", "", "", "Hello World")]
+    [InlineData("Hello World", "2", "", "", "", "", "Hello World")]
+    public void ShouldAppendFormatWithFiveArguments(string format, object arg1, object arg2, object arg3, object arg4, object arg5, string expected)
+    {
+        using var builder = new ValueStringBuilder();
+
+        builder.AppendFormat(format, arg1, arg2, arg3, arg4, arg5);
+
+        builder.ToString().Should().Be(expected);
+    }
 }