New ToString(Range) method

Author: linkdotnet

CHANGELOG.md

@@ -8,7 +8,8 @@ All notable changes to **ValueStringBuilder** will be documented in this file. T
 
 ### Added
 
-- New overload for `Append` that accepts a `ReadOnlyMemory`object
+- New overload for `Append` that accepts a `ReadOnlyMemory` object
+- New `ToString` overload that accepts a `Range` object
 
 ### Changed
 

src/LinkDotNet.StringBuilder/ValueStringBuilder.cs

@@ -109,6 +109,17 @@ public ValueStringBuilder(ReadOnlySpan<char> initialText)
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public readonly string ToString(int startIndex, int length) => new(buffer[startIndex..(startIndex + length)]);
 
+    /// <summary>
+    /// Creates a <see cref="string"/> instance from that builder in the given range.
+    /// </summary>
+    /// <param name="range">The range that will be retrieved.</param>
+    /// <returns>The <see cref="string"/> instance.</returns>
+    public readonly string ToString(Range range)
+    {
+        var (offset, length) = range.GetOffsetAndLength(bufferPosition);
+        return new string(buffer.Slice(offset, length));
+    }
+
     /// <summary>
     /// Returns the string as an <see cref="ReadOnlySpan{T}"/>.
     /// </summary>

tests/LinkDotNet.StringBuilder.UnitTests/ValueStringBuilderTests.cs

@@ -481,4 +481,12 @@ public void ShouldReverseString()
 
         builder.ToString().Should().Be("olleH");
     }
+
+    [Fact]
+    public void GivenAString_WhenCallingToStringWithRange_ThenShouldReturnSubstring()
+    {
+        using var builder = new ValueStringBuilder("Hello World");
+
+        builder.ToString(1..4).Should().Be("ell");
+    }
 }