Re: [PATCH] prio-queue: fold lazy_queue into prio_queue for automatic get+put fusion

[Junio C Hamano <gitster@pobox.com>]

Kristofer Karlsson <krka@spotify.com> writes:

> Agreed, that's the right fix. I looked for existing ways of marking
> fields as private, internal or hidden but the only thing I found was
> the convention of using a code comment: /* for internal use only */
>
> I will apply a rename and submit a v2. Perhaps something like
> nr_internal to make it look less like a public API.


I think we often use trailing underscore (e.g., "n_") to mark
variables for "not to be used casually, there are better ways to
access this information", which pre-ANSI C people probably used
leading underscore (e.g. "_n") for.

This is often used in callback functions where the types of their
formal parameters are specified by the API and use of them with
casting at every use site is awkward.  For example, qsort() and
friends often take a pointer to the location that stores the value
to be compared, but it is awkward, so we do cast just once upfront
like so:

static int compare_callback(const void *a_, const void *b_)
{
	const a_type a = *((const a_type *)a_);
	const a_type b = *((const a_type *)b_);

        ... use values 'a' and 'b', without having to cast a_ or b_ ...

	return a - b;
}

I think the technique/convention can be used in a similar way for
"this is hidden and unless you can tell if you should be using it
directly, you probably shouldn't" kind of structure members.

So, nr_internal is perfectly fine, but if you find it too long, nr_
is probably just as good.