These tools to me serve about two functions: writing regular expressions (and even then I'll tell it it's wrong once or twice before attempting to check the out

These tools to me serve about two functions: writing regular expressions (and even then I'll tell it it's wrong once or twice before attempting to check the output), and saving me keystrokes for code I already know I'll write but is easier to describe. In both cases I already know what code snippets I want mentally, and it saves me minutes at most.