C# RegEx based (No AST) syntax highlighting

CSharpSyntax.xshd

<SyntaxDefinition name="CSharp" xmlns="http://icsharpcode.net/sharpdevelop/syntaxdefinition/2008">

  <Color name="CommentSingle" foreground="#0cad31" />
  <Color name="CommentMulti" foreground="#068724" />
  <Color name="String" foreground="Orange" />
  <Color name="Char" foreground="DarkOrange" />
  <Color name="Digits" foreground="DarkBlue"/>

  <RuleSet>
    <Span color="CommentSingle" begin="//" />
    <Span color="CommentMulti" multiline="true"
          begin="/\*" end="\*/" />

    <Span color="String">
      <Begin>"</Begin>
      <End>"</End>
      <RuleSet>
        <!-- nested span for escape sequences -->
        <Span begin="\\" end="." />
      </RuleSet>
    </Span>
    <Span color="Char">
      <Begin>'</Begin>
      <End>'</End>
      <RuleSet>
        <!-- nested span for escape sequences -->
        <Span begin="\\" end="." />
      </RuleSet>
    </Span>

    <Keywords fontWeight="bold" foreground="LightBlue">
      <Word>abstract</Word>
      <Word>as</Word>
      <Word>async</Word>
      <Word>await</Word>
      <Word>base</Word>
      <Word>bool</Word>
      <Word>break</Word>
      <Word>byte</Word>
      <Word>case</Word>
      <Word>catch</Word>
      <Word>char</Word>
      <Word>checked</Word>
      <Word>class</Word>
      <Word>const</Word>
      <Word>continue</Word>
      <Word>decimal</Word>
      <Word>default</Word>
      <Word>delegate</Word>
      <Word>do</Word>
      <Word>double</Word>
      <Word>else</Word>
      <Word>enum</Word>
      <Word>event</Word>
      <Word>explicit</Word>
      <Word>extern</Word>
      <Word>false</Word>
      <Word>finally</Word>
      <Word>fixed</Word>
      <Word>float</Word>
      <Word>for</Word>
      <Word>foreach</Word>
      <Word>goto</Word>
      <Word>if</Word>
      <Word>implicit</Word>
      <Word>in</Word>
      <Word>int</Word>
      <Word>interface</Word>
      <Word>internal</Word>
      <Word>is</Word>
      <Word>lock</Word>
      <Word>long</Word>
      <Word>namespace</Word>
      <Word>new</Word>
      <Word>null</Word>
      <Word>object</Word>
      <Word>operator</Word>
      <Word>out</Word>
      <Word>override</Word>
      <Word>params</Word>
      <Word>private</Word>
      <Word>protected</Word>
      <Word>public</Word>
      <Word>readonly</Word>
      <Word>ref</Word>
      <Word>return</Word>
      <Word>sbyte</Word>
      <Word>sealed</Word>
      <Word>short</Word>
      <Word>sizeof</Word>
      <Word>stackalloc</Word>
      <Word>static</Word>
      <Word>string</Word>
      <Word>struct</Word>
      <Word>switch</Word>
      <Word>this</Word>
      <Word>throw</Word>
      <Word>true</Word>
      <Word>try</Word>
      <Word>typeof</Word>
      <Word>uint</Word>
      <Word>ulong</Word>
      <Word>unchecked</Word>
      <Word>unsafe</Word>
      <Word>ushort</Word>
      <Word>using</Word>
      <Word>var</Word>
      <Word>virtual</Word>
      <Word>void</Word>
      <Word>volatile</Word>
      <Word>while</Word>
      <Word>?</Word>
      <Word>,</Word>
      <Word>.</Word>
      <Word>;</Word>
      <Word>:</Word>
      <Word>)</Word>
      <Word>(</Word>
      <Word>[</Word>
      <Word>]</Word>
      <Word>{</Word>
      <Word>}</Word>
      <Word>+</Word>
      <Word>-</Word>
      <Word>/</Word>
      <Word>%</Word>
      <Word>*</Word>
      <Word>&lt;</Word>
      <Word>&gt;</Word>
      <Word>^</Word>
      <Word>=</Word>
      <Word>~</Word>
      <Word>!</Word>
      <Word>|</Word>
      <Word>&amp;</Word>
    </Keywords>

    <!-- Digits -->
    <Rule foreground="#ecffc4">
      \b0[xX][0-9a-fA-F]+  # hex number
      |    \b
      (    \d+(\.[0-9]+)?   #number with optional floating point
      |    \.[0-9]+         #or just starting with floating point
      )
      ([eE][+-]?[0-9]+)? # optional exponent
    </Rule>
    
    <!-- Types -->
    <Rule foreground="#408E66">
      (^|\s)[A-Z][a-zA-Z]*[0-9]*
    </Rule>
  </RuleSet>
</SyntaxDefinition>