# File lib/sfl.rb, line 136
    def eval_ast(ast)
      case ast
      when Array
        if ast.size > 2
          eval_ast(ast[0]).send(ast[1], *ast[2..-1].map {|i| eval_ast(i) })
        else
          eval_ast(ast[0]).send(ast[1])
        end
      else
        ast
      end
    end