Macros in php

[Emil]

Is there any hope that new versions of PHP
will support macros similar to C or C++?
I've searched manual and didn't find anything
except define directive, but it can be used
to define constant values only.
Of course it is not THAT neccessary functionality,
but it could be very useful.

greetz Emil

[Kimmo Laine]

"Emil" <em************ **@podczta.onet .pl> wrote in message
news:e1******** **@news.onet.pl ...

Is there any hope that new versions of PHP
will support macros similar to C or C++?
I've searched manual and didn't find anything
except define directive, but it can be used
to define constant values only.
Of course it is not THAT neccessary functionality,
but it could be very useful.

What's the actual difference between a function and a macro? How would use
of macros differ from functions?

Let's pretend there is a way of defining a macro in php...
define ("MAX($a,$b) ", "(($a<$b)?$b:$a )");

vs.

function max( $a, $b ) {
return $a < $b ? $b : $a;
}

And use them like this:
MAX($a,$b); // This is macro, so much easier!
max($a,$b); // This is plain old dull function! Bah, no no, not like
this...

I mean.... WTF?

--
"ohjelmoija on organismi joka muuttaa kofeiinia koodiksi" -lpk
sp**@outolempi. net | Gedoon-S @ IRCnet | rot13(xv***@bhg byrzcv.arg)

[Jerry Stuckle]

Kimmo Laine wrote:

"Emil" <em************ **@podczta.onet .pl> wrote in message
news:e1******** **@news.onet.pl ...

Is there any hope that new versions of PHP
will support macros similar to C or C++?
I've searched manual and didn't find anything
except define directive, but it can be used
to define constant values only.
Of course it is not THAT neccessary functionality,
but it could be very useful.

What's the actual difference between a function and a macro? How would use
of macros differ from functions?

Let's pretend there is a way of defining a macro in php...
define ("MAX($a,$b) ", "(($a<$b)?$b:$a )");

vs.

function max( $a, $b ) {
return $a < $b ? $b : $a;
}

And use them like this:
MAX($a,$b); // This is macro, so much easier!
max($a,$b); // This is plain old dull function! Bah, no no, not like
this...

I mean.... WTF?

Macros are more efficient.

Personally, one construct I use heavily and would like to replace with a macro:

$var = isset($_POST['postvar']) ? $_POST['postvar'] . 'default value';

I use something similar for a get/post, session and cookie values. It would be
very nice to have a macro.

--
=============== ===
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attgl obal.net
=============== ===

[Kimmo Laine]

"Jerry Stuckle" <js*******@attg lobal.net> wrote in message
news:GL******** *************** *******@comcast .com...

Kimmo Laine wrote:

"Emil" <em************ **@podczta.onet .pl> wrote in message
news:e1******** **@news.onet.pl ...

Is there any hope that new versions of PHP
will support macros similar to C or C++?
I've searched manual and didn't find anything
except define directive, but it can be used
to define constant values only.
Of course it is not THAT neccessary functionality,
but it could be very useful.

What's the actual difference between a function and a macro? How would
use of macros differ from functions?

Let's pretend there is a way of defining a macro in php...
define ("MAX($a,$b) ", "(($a<$b)?$b:$a )");

vs.

function max( $a, $b ) {
return $a < $b ? $b : $a;
}

And use them like this:
MAX($a,$b); // This is macro, so much easier!
max($a,$b); // This is plain old dull function! Bah, no no, not like
this...

I mean.... WTF?

Macros are more efficient.

Personally, one construct I use heavily and would like to replace with a
macro:

$var = isset($_POST['postvar']) ? $_POST['postvar'] . 'default value';

I use something similar for a get/post, session and cookie values. It
would be very nice to have a macro.

And tell mme again why you couldn't write a function instead of a macro to
do that?

Just so we all remember what we're talking about here... In C a macro is a
syntax replacement that the precompiler uses to both optimize the code
(avoid the unnecessary function jump for a short task) and make it easy to
write for the coder. The complier simply translates a pseudo code (the
macro) to actual code when the code is compiled to executable. Since PHP is
not precompiled, I don't see how this could be of any use. The php source
code should be precompiled in order to get the replaced... Macros just don't
have a purpouse in run-time compiled language like they do in precompiled
languages.

--
"ohjelmoija on organismi joka muuttaa kofeiinia koodiksi" -lpk
sp**@outolempi. net | Gedoon-S @ IRCnet | rot13(xv***@bhg byrzcv.arg)

[Jerry Stuckle]

Kimmo Laine wrote:

"Jerry Stuckle" <js*******@attg lobal.net> wrote in message
news:GL******** *************** *******@comcast .com...

Kimmo Laine wrote:

"Emil" <em************ **@podczta.onet .pl> wrote in message
news:e1***** *****@news.onet .pl...
Is there any hope that new versions of PHP
will support macros similar to C or C++?
I've searched manual and didn't find anything
except define directive, but it can be used
to define constant values only.
Of course it is not THAT neccessary functionality,
but it could be very useful.


What's the actual difference between a function and a macro? How would
use of macros differ from functions?

Let's pretend there is a way of defining a macro in php...
define ("MAX($a,$b) ", "(($a<$b)?$b:$a )");

vs.

function max( $a, $b ) {
return $a < $b ? $b : $a;
}

And use them like this:
MAX($a,$b) ; // This is macro, so much easier!
max($a,$b) ; // This is plain old dull function! Bah, no no, not like
this...

I mean.... WTF?

Macros are more efficient.

Personally, one construct I use heavily and would like to replace with a
macro:

$var = isset($_POST['postvar']) ? $_POST['postvar'] . 'default value';

I use something similar for a get/post, session and cookie values. It
would be very nice to have a macro.

And tell mme again why you couldn't write a function instead of a macro to
do that?

Just so we all remember what we're talking about here... In C a macro is a
syntax replacement that the precompiler uses to both optimize the code
(avoid the unnecessary function jump for a short task) and make it easy to
write for the coder. The complier simply translates a pseudo code (the
macro) to actual code when the code is compiled to executable. Since PHP is
not precompiled, I don't see how this could be of any use. The php source
code should be precompiled in order to get the replaced... Macros just don't
have a purpouse in run-time compiled language like they do in precompiled
languages.

I know exactly what a macro is in C - I've been programming C for over 20 years.

And yes, the can still be more efficient in PHP. Remember - each page is NOT
reparsed every time it is requested. PHP can also cache pages, then pull the
code right from the cache.

So yes, they can be more efficient.

--
=============== ===
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attgl obal.net
=============== ===

[Emil]

Kimmo Laine napisa³(a):

$var = isset($_POST['postvar']) ? $_POST['postvar'] . 'default value';

I have the same problem.

And tell mme again why you couldn't write a function instead of a macro to
do that?

The reason is when you pass $_POST['postvar'] to a function and
$_POST['postvar'] is not set, PHP generates warning. Of course one could
turn off warnings and usually does, but in my opinion it's not a
solution. However checking everytime if variable (or array index) is set
before passing it to a function generates sometimes tones of similar
code which could be simply replaced with one elegant macro.
Maybe it's just a matter of programmer's habit, I feel lack of macros.

Greetz Emil

[Ian McConnell]

"Kimmo Laine" <sp**@outolempi .net> writes:

"Emil" <em************ **@podczta.onet .pl> wrote in message
news:e1******** **@news.onet.pl ...

Is there any hope that new versions of PHP
will support macros similar to C or C++?
I've searched manual and didn't find anything
except define directive, but it can be used
to define constant values only.
Of course it is not THAT neccessary functionality,
but it could be very useful.

What's the actual difference between a function and a macro? How would use
of macros differ from functions?

Just the other day, I was thinking that a preprocessor in PHP would be
handy. I've got a lot of code that goes

<?php
include 'cache.inc';
$c = new cache;
if ($c->uncached()) {

... main body of php code

}
$c->end(); // cache and/or display html
include 'stats_counter. inc';
?>

It would be nice to replace this with

<?php
START_CACHING;

... main body of php code

END_CACHING;
?>

but I can't see how this can be done neatly[*] with functions.
Ian

[*] It could be done badly with cache.php?inc=m ycode.php where
cache.php is something like

<?php
include 'cache.inc';
$c = new cache;
if ($c->uncached()) {

include $_GET['inc'];

}
$c->end(); // cache and/or display html
include 'stats_counter. inc';
?>

[Chung Leong]

Jerry Stuckle wrote:

Macros are more efficient.

Personally, one construct I use heavily and would like to replace with a macro:

$var = isset($_POST['postvar']) ? $_POST['postvar'] . 'default value';

I use something similar for a get/post, session and cookie values. It would be
very nice to have a macro.

I think the operation is common enough that it deserves a function-like
operator. Something like

$val = coalesce($_POST['postvar'], $_SESSION['postvar'], 'default
value');

[Dana Cartwright]

"Ian McConnell" <ia*@emit.demon .co.uk> wrote in message
news:87******** ****@emit.demon .co.uk...

Just the other day, I was thinking that a preprocessor in PHP would be
handy. I've got a lot of code that goes

<?php
include 'cache.inc';
$c = new cache;
if ($c->uncached()) {

... main body of php code

}
$c->end(); // cache and/or display html
include 'stats_counter. inc';
?>

It would be nice to replace this with

<?php
START_CACHING;

... main body of php code

END_CACHING;
?>

Any piece of software is essentially a series of mental concepts, written
down as computer code. So what you are saying (and I agree heartily) is:
See this series of PHP statements? They represent a concept called "Start
Caching".

So it makes sense to write START_CACHING rather than spell out the details.
I think it makes the code easier to read, both for the author and any other
soul who has to learn it.

This aspect of macros has nothing to do with computer efficiency, but a
great deal to do with human efficiency. We *like* to name things.
Languages should accomodate this.

What's nice about macros is that they can be used to name rather arbitrary
stuff, including fragments of code. Functions have a different role to
play.

-Dana

[Jiri Fogl]

> What's the actual difference between a function and a macro? How would use

of macros differ from functions?

I was working on modular system, where every module was a file with
object definition.

I needed to make some global variables accessible in method of this
object (i.e. database connection object) in every module, but I wanted
to have a list of these variables only once in whole system (it would be
unpleasant to edit all modules if I decided to, for example, change name
of any of these variables).

Function is useless in this case, so I needed a macro.

I solved a problem this way:

// In initialisation part of code
define('MY_MACR O', 'global $database, $global_config,
$any_other_need ed_variables;') ;

// In beginning of module object's method
eval (MY_MACRO);

But maybe there is much better way to do this