bug#12215: CSET is unnecessarily confusing

[Dmitry Antipov <dmantipov@yandex.ru>]

On 08/17/2012 04:04 AM, Paul Eggert wrote:
> Recent changes to Emacs have introduced code like the following:
>
>     CSET (XCHAR_TABLE (char_table), parent, parent);
>
> This is unnecessarily confusing.  Those two 'parent' expressions
> refer to different things; the first 'parent' is not really a C
> expression at all.  I recall that Stefan also expressed unease about
> CSET's not acting like a function, in this respect.
>
> It's easy to change lisp.h so that the same code can be
> written as follows, which is shorter and clearer:
>
>    char_table_set_parent (char_table, parent);
>
> The main objection to changing lisp.h, if I recall correctly, is that
> it will make lisp.h longer, since lisp.h will need a separate setter
> function for each field.  But that's not much of a problem since
> these functions are really simple.  And the advantage of readability
> in users of the code makes the .h change worthwhile.
>
> Here's a patch to make this change for CSET.  I'd like to install this,
> along with similar patches for the other non-function ?SET macros defined
> recently.

OK

Dmitry