CodeHighlighter.addStyle("ruby", {
  expression: {
    exp: /(["'].*)(#\{.*\})(.*['"])/,
    replacement: "<span class='string'>$1</span><span class='expression'>$2</span><span class='string'>$3</span>"
  },
  expression_in_shell_command: {
    exp: /([`].*)(#\{.*\})(.*[`])/,
    replacement: "<span class='shell-command'>$1</span><span class='expression'>$2</span><span class='shell-command'>$3</span>"
  },
	comment: {
		exp: /#[^\n]+/
	},
	brackets: {
		exp: /\(|\)/
	},
	string: {
		exp: /'[^']*'|"[^"]*"/
	},
	keywords: {
		exp: /\b(do|end|self|class|def|if|module|yield|then|else|for|until|unless|while|elsif|case|when|break|retry|redo|rescue|require|raise)\b/
	},
	symbol: {
		exp: /([^:])(:[A-Za-z0-9_!?]+)/
	},
	regexp: {
	  exp: /\/.*\//
	}
});