add_expression

# File actionview/lib/action_view/template/handlers/erb/erubi.rb, line 47
          def add_expression(indicator, code)
            flush_newline_if_pending(src)

            with_buffer do
              if (indicator == "==") || @escape
                src << ".safe_expr_append="
              else
                src << ".append="
              end

              if BLOCK_EXPR.match?(code)
                src << " " << code
              else
                src << "(" << code << ")"
              end
            end
          end