Ruby.tmLanguage

    <!-- elgalu: Adding ruby regular expression detection starting and ending with slashes -->
    <dict>
      <key>begin</key>
      <string>/</string>
      <key>beginCaptures</key>
      <dict>
        <key>0</key>
        <dict>
          <key>name</key>
          <string>punctuation.definition.string.begin.ruby</string>
        </dict>
      </dict>
      <key>comment</key>
      <string>regular expressions (literal)</string>
      <key>end</key>
      <string>/[eimnosux]*</string>
      <key>endCaptures</key>
      <dict>
        <key>0</key>
        <dict>
          <key>name</key>
          <string>punctuation.definition.string.end.ruby</string>
        </dict>
      </dict>
      <key>name</key>
      <string>string.regexp.mod-r.ruby</string>
      <key>patterns</key>
      <array>
        <dict>
          <key>include</key>
          <string>#regex_sub</string>
        </dict>
      </array>
    </dict>