module EJS

def compile(source, options = {})


# => "function(obj){...}"
EJS.compile("Hello <%= name %>")

template.
`compile` if you want to specify a different tag syntax for the
`:evaluation_pattern` and `:interpolation_pattern` options to
variables in the template. You can optionally pass the
function takes an optional argument, an object specifying local
Compiles an EJS template to a JavaScript function. The compiled 
def compile(source, options = {})
  source = source.dup
  escape_quotes!(source)
  replace_escape_tags!(source, options)
  replace_interpolation_tags!(source, options)
  replace_evaluation_tags!(source, options)
  escape_whitespace!(source)
  "function(obj){var __p=[],print=function(){__p.push.apply(__p,arguments);};" +
    "with(obj||{}){__p.push('#{source}');}return __p.join('');}"
end

def escape_function 

def escape_function
  ".replace(/&/g, '&amp;')" +
  ".replace(/</g, '&lt;')" +
  ".replace(/>/g, '&gt;')" +
  ".replace(/\"/g, '&quot;')" +
  ".replace(/'/g, '&#x27;')" +
  ".replace(/\\//g,'&#x2F;')"
end

def escape_quotes!(source) 

def escape_quotes!(source)
  source.gsub!(/\\/) { '\\\\' }
  source.gsub!(/'/) { "\\'" }
end

def escape_whitespace!(source) 

def escape_whitespace!(source)
  source.gsub!(/\r/, '\\r')
  source.gsub!(/\n/, '\\n')
  source.gsub!(/\t/, '\\t')
end

def evaluate(template, locals = {}, options = {})


# => "Hello world"
EJS.evaluate("Hello <%= name %>", :name => "world")

JavaScript runtime available.
(https://github.com/sstephenson/execjs/) library and a
compiler options. You will need the ExecJS
Evaluates an EJS template with the given local variables and 
def evaluate(template, locals = {}, options = {})
  require "execjs"
  context = ExecJS.compile("var evaluate = #{compile(template, options)}")
  context.call("evaluate", locals)
end

def replace_escape_tags!(source, options) 

def replace_escape_tags!(source, options)
  source.gsub!(options[:escape_pattern] || escape_pattern) do
    "',(''+" + $1.gsub(/\\'/, "'") + ")#{escape_function},'"
  end
end

def replace_evaluation_tags!(source, options) 

def replace_evaluation_tags!(source, options)
  source.gsub!(options[:evaluation_pattern] || evaluation_pattern) do
    "');" + $1.gsub(/\\'/, "'").gsub(/[\r\n\t]/, ' ') + "; __p.push('"
  end
end

def replace_interpolation_tags!(source, options) 

def replace_interpolation_tags!(source, options)
  source.gsub!(options[:interpolation_pattern] || interpolation_pattern) do
    "'," + $1.gsub(/\\'/, "'") + ",'"
  end
end