> +Entry to this mode calls the value of `ruby-mode-hook'
> +if that value is non-nil."
That's problematic:
- it's redundant since define-derived-mode already adds "In addition to
any hooks its parent mode `prog-mode' might have run,\nthis mode runs
the hook `ruby-mode-hook', as the final step\nduring initialization."
- hooks aren't "called" but are "run".
- it's not just "the value of `ruby-mode-hook'", but the *values*, since
hooks use both the buffer-local and the global value of the symbol.
- the hook is run even if it is nil (or unbound): running it will simply
not do anything.
Stefan