working with delimiters
Use c% to change text within delimiters. Example:
link_to("text", my_path(singularize("one"), pluralize(double("two"))))
^ A B
"It also handles [] square brackets, {} curly braces and some other things. It can be used as a standalone motion or with other operators than c.
For example, you could use %d% to change remove_my_argument(BigDecimal(123)) into remove_my_argument."