David,
Well, I probably don't have a NEED for it. I've gotten along for 25+
years without it. :-)
However, what prompted my inquiry is using it would've saved me tracking
down a few bugs in recent weeks. Some prior code was re-used for a
similar function, but the name of the recursive calls weren't updated in
every case. It didn't take long to debug, but I realized that had it
always been written as self() it never would've been an issue.
I can also see a use for generated code where there's a base source code
template in use with an embedded include file reference that changes as
it's generated per pass, such as:
int step1(int a, int b)
{
#include "\current_task\step1.cpp"
}
int step2(int a, int b)
{
#include "\current_task\step2.cpp"
}
Using the self() reference for recursion, one could modify stepN.cpp's
generator algorithms without having to know or care anything in the
wrapper code. Likewise, the wrapper could be modified without having to
concern itself with anything in the generated code, save some
requirements of an API like a "print_notice()" or "print_error()"
message function, which could just be a requirement of the app to always
be there. The rest, however, could be fluid.
A few other uses I can think of as well. Minor ones.
Best regards,
Rick C. Hodgin
On 06/14/2012 04:24 PM, David Brown wrote:
On 14/06/12 19:31, Joe Buck wrote:
It only saves one character in any case: your "self" is just "*this".
No, "this" points to the object in C++. The OP's "self" is referring
to the function being compiled. So here "self" would be the same as
"foo".
I don't think there is any way to get this without making a language
extension, unless there is some way of turning the string __FUNC__
into the function. But I also don't see any advantage over simply
using the function name directly. After all, how often do you need
recursion - and what is the problem with writing out the function name
in full on those occasions?
mvh.,
David
________________________________________
From: gcc-ow...@gcc.gnu.org [gcc-ow...@gcc.gnu.org] on behalf of Ian
Lance Taylor [i...@google.com]
Sent: Thursday, June 14, 2012 10:19 AM
To: Rick C. Hodgin
Cc: gcc@gcc.gnu.org
Subject: Re: "self" keyword
"Rick C. Hodgin"<foxmuldrs...@yahoo.com> writes:
I was thinking C and C++.
int myclass::foo(int a)
{
// recursion
self(a + 1);
}
Just out of curiosity, why wouldn't it be accepted back into mainline?
In general these days GCC discourages language extensions. They would
have to have a compelling advantage. I don't see that here. Even if I
did, I would recommend running it through a language standards body
first.
Ian
