class Erubis::TinyEruby

#
# print eruby.evalute(context) # eval ruby code with context object
# print eruby.result(binding()) # eval ruby code with Binding object
# print eruby.src # print ruby code
# eruby = TinyEruby.new(File.read(‘example.rhtml’))
# ex.
#
# tiny and the simplest implementation of eRuby
#

def convert(input) 

def convert(input)
  src = "_buf = '';"           # preamble
  pos = 0
  input.scan(EMBEDDED_PATTERN) do |indicator, code|
    m = Regexp.last_match
    text = input[pos...m.begin(0)]
    pos  = m.end(0)
    #src << " _buf << '" << escape_text(text) << "';"
    text.gsub!(/['\\]/, '\\\\\&')
    src << " _buf << '" << text << "';" unless text.empty?
    if !indicator              # <% %>
      src << code << ";"
    elsif indicator == '#'     # <%# %>
      src << ("\n" * code.count("\n"))
    else                       # <%= %>
      src << " _buf << (" << code << ").to_s;"
    end
  end
  #rest = $' || input                        # ruby1.8
  rest = pos == 0 ? input : input[pos..-1]   # ruby1.9
  #src << " _buf << '" << escape_text(rest) << "';"
  rest.gsub!(/['\\]/, '\\\\\&')
  src << " _buf << '" << rest << "';" unless rest.empty?
  src << "\n_buf.to_s\n"       # postamble
  return src
end

def evaluate(_context=Object.new) 

def evaluate(_context=Object.new)
  if _context.is_a?(Hash)
    _obj = Object.new
    _context.each do |k, v| _obj.instance_variable_set("@#{k}", v) end
    _context = _obj
  end
  _context.instance_eval @src
end

def initialize(input=nil) 

def initialize(input=nil)
  @src = convert(input) if input
end

def result(_binding=TOPLEVEL_BINDING) 

def result(_binding=TOPLEVEL_BINDING)
  eval @src, _binding
end