Add JSON text renderer (#1086)

* Add JsonText widget to render highlighted JSON

Closes #1051

src/Spectre.Console/Extensions/CharExtensions.cs

@@ -3,7 +3,7 @@ namespace Spectre.Console;
 /// <summary>
 /// Contains extension methods for <see cref="char"/>.
 /// </summary>
-public static class CharExtensions
+public static partial class CharExtensions
 {
     /// <summary>
     /// Gets the cell width of a character.

src/Spectre.Console/Internal/Extensions/CharExtensions.cs

@@ -0,0 +1,9 @@
+namespace Spectre.Console.Internal;
+
+internal static partial class CharExtensions
+{
+    public static bool IsDigit(this char character, int min = 0)
+    {
+        return char.IsDigit(character) && character >= (char)min;
+    }
+}

src/Spectre.Console/Internal/Extensions/EnumerableExtensions.cs

@@ -118,7 +118,7 @@ internal static class EnumerableExtensions
     }
 #endif
 
-    public static IEnumerable<(TFirst First, TSecond Second, TThird Third)> Zip<TFirst, TSecond, TThird>(
+    public static IEnumerable<(TFirst First, TSecond Second, TThird Third)> ZipThree<TFirst, TSecond, TThird>(
         this IEnumerable<TFirst> first, IEnumerable<TSecond> second, IEnumerable<TThird> third)
     {
         return first.Zip(second, (a, b) => (a, b))

src/Spectre.Console/Internal/Ratio.cs

@@ -89,7 +89,7 @@ internal static class Ratio
         var totalRemaining = total;
         var result = new List<int>();
 
-        foreach (var (ratio, maximum, value) in ratios.Zip(maximums, values))
+        foreach (var (ratio, maximum, value) in ratios.ZipThree(maximums, values))
         {
             if (ratio != 0 && totalRatio > 0)
             {

src/Spectre.Console/Internal/Text/StringBuffer.cs

@@ -23,11 +23,22 @@ internal sealed class StringBuffer : IDisposable
         _reader.Dispose();
     }
 
+    public char Expect(char character)
+    {
+        var read = Read();
+        if (read != character)
+        {
+            throw new InvalidOperationException($"Expected '{character}', but found '{read}'");
+        }
+
+        return read;
+    }
+
     public char Peek()
     {
         if (Eof)
         {
-            throw new InvalidOperationException("Tried to peek past the end of the text.");
+            return '\0';
         }
 
         return (char)_reader.Peek();
@@ -37,7 +48,7 @@ internal sealed class StringBuffer : IDisposable
     {
         if (Eof)
         {
-            throw new InvalidOperationException("Tried to read past the end of the text.");
+            return '\0';
         }
 
         Position++;

src/Spectre.Console/Spectre.Console.csproj

@@ -36,6 +36,10 @@
     </PackageReference>
   </ItemGroup>
 
+  <ItemGroup>
+    <Folder Include="Widgets\Json\" />
+  </ItemGroup>
+
   <PropertyGroup>
     <DefineConstants>$(DefineConstants)TRACE;WCWIDTH_VISIBILITY_INTERNAL</DefineConstants>
   </PropertyGroup>