IDEs could make it readable and encourage to split code without splitting perception. A solution is: allow calls to be ▶expanded inline in the source view, as if it was written here* Renaming arguments to their caller-site counterparts would also help.

* Code folding is not the same thing, as it doesn’t eject scope+args out of the “caller” and cannot be used in expression.

Upd: I also would like to add that sources lack usual style formatting. //-sections usually should stand out, but one can only make comment bigger (2-3 lines with === filler), but not the text itself. It would be nice to have some rtf in code and css in IDE. Books are written like that, and that’s well-acknowledged way to structure instructions and descriptions.