Re: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
David L. Nicol wrote: No, that does not work: Right; I misunderstood what was wanted. -- John Porter
RE: aliasing - was:[nice2haveit]
Stuart Rocks wrote:
CWith would also make the [variable, alias, whatever]
default, but not replace the $_:
$_ = monkey ;
$foo = coward;
with ($foo){
print;
print $_;
}
would output monkey coward.
okay, coward is default but $_ has not been replaced, so would not
the code example print coward monkey
Then how would you write I am not a coward
with ($foo)
{
print I am not a; ##What do I use here or do I have to issue a
##separate print like...
print;
}
Ilya
Re: aliasing - was:[nice2haveit]
Then how would you write I am not a coward
with ($foo)
{
print I am not a; ##What do I use here or do I have to issue a
##separate print like...
print;
}
Ilya
Well in Perl5, for the print to use default value it's just 'print;'. The
same applies for alot (all?) of Perl5 functions. The default value is always
(as far as I know) $_ or @_ depending on the context.
Both the following would work:
with($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
The idea for this style of CWith, came because I don't see why the default
has to always be $_. Often the amount of code required would be able to be
dramatically reduced if 'default value' was userdefinable for blocks with
the With command.
(All opinions in this post are not representative of Monkey Coward)
what's with 'with'? (was: [aliasing - was:[nice2haveit]])
From: Stuart Rocks [mailto:[EMAIL PROTECTED]]
Both the following would work:
with($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
Okay... I've been mostly ignoring this thread. But can someone reiterate the
difference between the above and
for($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
???
Re: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
Garrett Goebel wrote:
From: Stuart Rocks [mailto:[EMAIL PROTECTED]]
Both the following would work:
with($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
Okay... I've been mostly ignoring this thread. But can someone reiterate the
difference between the above and
for($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
???
pure syntax. does anyone else question making aliases like 'with' from 'for'?
a 'with' alias could open the door on purely confusing code like this:
with( my $i; $i 10; $i++ ){ ... }
instead of having an standard 'with' that only works on objects like this:
with( MyObject-new() ) {
.setIt(blah);
...
}
--
-mark koopman
WebSideStory 10182 Telesis Court
San Diego CA 92121 858-546-1182 ext 318
RE: aliasing - was:[nice2haveit]
But I thought this was related to more than just with(), so if we have
foreach (1..10)
{
print;
### But if you are trying to use it in a string
print This is number $_ of 10\n;
### Would now have to be printed as
print This is number ;
print;
print of 10\n;
### Which is three extra statement.
}
I still believe that although not defining a variable source will use the
temp variable there is still a need for an explicit scalar like $_.
Unless there is something I am missing from this discussion.
Ilya
-Original Message-
From: Stuart Rocks
To: [EMAIL PROTECTED]
Sent: 07/19/2001 11:31 AM
Subject: Re: aliasing - was:[nice2haveit]
Then how would you write I am not a coward
with ($foo)
{
print I am not a; ##What do I use here or do I have to issue a
##separate print like...
print;
}
Ilya
Well in Perl5, for the print to use default value it's just 'print;'.
The
same applies for alot (all?) of Perl5 functions. The default value is
always
(as far as I know) $_ or @_ depending on the context.
Both the following would work:
with($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
The idea for this style of CWith, came because I don't see why the
default
has to always be $_. Often the amount of code required would be able to
be
dramatically reduced if 'default value' was userdefinable for blocks
with
the With command.
(All opinions in this post are not representative of Monkey Coward)
RE: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
Well if you look at the proposed...
$_ = monkey ;
$foo = coward;
with ($foo){
print;
print $_;
}
Would print coward monkey, which will give you unexpected results if you
are used to having the same output for both, coward coward.
But I guess the above would not replace $_ which would be very inconvenient
if you had to output it with a whole bunch of other stuff. Like I am not a
coward which can be easily done with print I am not a $_; will now have
to be written in two separate lines, and possibly more if there is more to
follow.
Ilya
-Original Message-
From: Garrett Goebel
To: 'Stuart Rocks'; [EMAIL PROTECTED]
Sent: 07/19/2001 12:34 PM
Subject: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
From: Stuart Rocks [mailto:[EMAIL PROTECTED]]
Both the following would work:
with($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
Okay... I've been mostly ignoring this thread. But can someone reiterate
the
difference between the above and
for($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
???
RE: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
I question this too, since as you mentioned with, in my experience works
nicely to reference and object like
with(object)
{
.foo();
.bar();
}
Ilya
-Original Message-
From: Mark Koopman
To: [EMAIL PROTECTED]
Sent: 07/19/2001 12:42 PM
Subject: Re: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
Garrett Goebel wrote:
From: Stuart Rocks [mailto:[EMAIL PROTECTED]]
Both the following would work:
with($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
Okay... I've been mostly ignoring this thread. But can someone
reiterate the
difference between the above and
for($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
???
pure syntax. does anyone else question making aliases like 'with' from
'for'?
a 'with' alias could open the door on purely confusing code like this:
with( my $i; $i 10; $i++ ){ ... }
instead of having an standard 'with' that only works on objects like
this:
with( MyObject-new() ) {
.setIt(blah);
...
}
--
-mark koopman
WebSideStory 10182 Telesis Court
San Diego CA 92121 858-546-1182 ext 318
Re: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
I believe what is really wanted is for for to be able to iterate
over lists of arrays or hashes:
for my @i ( @foo, @bar ) { ...
for my %i ( %foo, %bar ) { ...
with real aliasing occuring.
If @_ and %_ are the default iterator variables, then imagine:
for ( @argset1, @argset2 ) {
quux;
But I'm not convinced of the utility of this over using
scalar references.
--
John Porter
Re: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
Like I am not a coward which can be easily done with print I am not a $_; will now have to be written in two separate lines, and possibly more if there is more to follow. Ilya Um, of course the original way is still possible!
Re: aliasing - was:[nice2haveit]
Sterin, Ilya wrote: But I thought this was related to more than just with(), so if we have ### Would now have to be printed as print This is number ; print; print of 10\n; I still believe that although not defining a variable source will use the temp variable there is still a need for an explicit scalar like $_. Unless there is something I am missing from this discussion. No. with() must be consistent with other perl constructs. If implemented, it will use $_. Plain and simple. -- John Porter
RE: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
Well then maybe $_ can be a reference to a multidimensional array or hash,
and temp vars can be access like this.
for ( @foo, @bar ) {
print $_-[0] : $_-[1]\n;
}
As for hashes it might hold the key, also in an multidimensional array.
Ilya
-Original Message-
From: John Porter
To: [EMAIL PROTECTED]
Sent: 07/19/2001 12:59 PM
Subject: Re: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
I believe what is really wanted is for for to be able to iterate
over lists of arrays or hashes:
for my @i ( @foo, @bar ) { ...
for my %i ( %foo, %bar ) { ...
with real aliasing occuring.
If @_ and %_ are the default iterator variables, then imagine:
for ( @argset1, @argset2 ) {
quux;
But I'm not convinced of the utility of this over using
scalar references.
--
John Porter
RE: aliasing - was:[nice2haveit]
Agree. I think that with() should only be used with object references only, and $_ should be set accordingly. Ilya -Original Message- From: John Porter To: [EMAIL PROTECTED] Sent: 07/19/2001 1:01 PM Subject: Re: aliasing - was:[nice2haveit] Sterin, Ilya wrote: But I thought this was related to more than just with(), so if we have ### Would now have to be printed as print This is number ; print; print of 10\n; I still believe that although not defining a variable source will use the temp variable there is still a need for an explicit scalar like $_. Unless there is something I am missing from this discussion. No. with() must be consistent with other perl constructs. If implemented, it will use $_. Plain and simple. -- John Porter
Re: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
But can someone reiterate the
difference between the above and
for($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
Try this under the current for system, cause it's unclear what will happen
for those new to Perl:
$foo=monkey; $_= coward;
for($foo){
print;
$_ = hero;
}
print;
What is printed is monkey coward, rather than monkey hero. In addition,
$foo is now hero.
I suppose there isn't a huge difference. Either way, all this talk has
probably taken longer than it would take to write the thing.
Re: aliasing - was:[nice2haveit]
Bart Lateur wrote:
So, in this case, a with synonym for for would work.
But this only works for scalars. You can't have a %foo alias to
%Some::Other::hash this way, or a @bar alias to @Some::Other::array.
Sounds like what we really want is a form of for which can iterate
over a list of hashes or arrays:
for my @a ( @foo, @bar ) { ...
for my %h ( %foo, %bar ) { ...
--
John Porter
RE: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
Why would you want it to print Monkey Hero, I would expect $_ to be
localized, rather than global, which could prove more convenient.
Ilya
-Original Message-
From: Stuart Rocks
To: [EMAIL PROTECTED]
Sent: 07/19/2001 1:13 PM
Subject: Re: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
But can someone reiterate the
difference between the above and
for($foo){
print I am not a $foo\n;
# or:
print I am not a ;
print;
}
Try this under the current for system, cause it's unclear what will
happen
for those new to Perl:
$foo=monkey; $_= coward;
for($foo){
print;
$_ = hero;
}
print;
What is printed is monkey coward, rather than monkey hero. In
addition,
$foo is now hero.
I suppose there isn't a huge difference. Either way, all this talk has
probably taken longer than it would take to write the thing.
Re: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
Sterin, Ilya wrote:
Well then maybe $_ can be a reference to a multidimensional array or hash,
and temp vars can be access like this.
for ( @foo, @bar ) {
print $_-[0] : $_-[1]\n;
}
That's bizarre and unnecessary. We can already do this:
for ( \@foo, \@bar ) {
print $_-[0] : $_-[1]\n;
}
--
John Porter
RE: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
@foo = (foo1, foo2);
@bar = (bar1, bar2);
for ( \@foo, \@bar ) {
print $_-[0] : $_-[1]\n;
}
will output
foo1 : foo2
bar1 : bar2
I was thinking more of iterating through them at the same time, which would
sort of like compare them. I believe this was the initial topic of this
thread (I believe, that was about two days ago, my mind might be going blank
though).
So my initial code (which I modified a little...)
for ( @foo, @bar ) {
print $_[0] : $_[1]\n;
}
for would set each element of the @_ array to correspond to the arguments in
for() , therfore $_[0] will equal to the current element of @foo and $_[1]
will equal to the corresponding element of @bar. As I mentioned before this
can very easily be accomplished through 0..$#foo loop, but people disagreed
based on that it would be a nice option, in my opinion it's useless, but if
was implemented this could be a way:)
Ilya
-Original Message-
From: 'John Porter '
To: [EMAIL PROTECTED]
Sent: 07/19/2001 1:46 PM
Subject: Re: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
Sterin, Ilya wrote:
Well then maybe $_ can be a reference to a multidimensional array or
hash,
and temp vars can be access like this.
for ( @foo, @bar ) {
print $_-[0] : $_-[1]\n;
}
That's bizarre and unnecessary. We can already do this:
for ( \@foo, \@bar ) {
print $_-[0] : $_-[1]\n;
}
--
John Porter
Re: what's with 'with'? (was: [aliasing - was:[nice2haveit]])
Why would you want it to print Monkey Hero, I would expect $_ to be localized, rather than global, which could prove more convenient. No, it's still localized. But the With would mean that $_ in a way becomes a normal variable like $foo was, and the $foo is now the 'default variable'.
Re: aliasing - was:[nice2haveit]
Sounds like what we really want is a form of for which can iterate
over a list of hashes or arrays:
for my @a ( @foo, @bar ) { ...
for my %h ( %foo, %bar ) { ...
Yes.
Isn't the underlying issue in the above how perl6 handles manipulation
and aliasing of multi-dimensional arrays into derived sub-structures?
In other words, isn't there a more general problem of how to provide
MD access and what to do with the currently one dimensional operations
like:
for (@foo) {
when @foo is multi-dimensional?
Jeremy Howard wrote RFCs that I think relate to this and pointed
me to J (APL cleaned up) as a powerful source of related ideas.
I think the specific issue above relates to a combination of
merge/unmerge and other proposed features.
Re: aliasing - was:[nice2haveit]
Jeremy Howard wrote:
with $XL-{Application}-{ActiveSheet} {
-cells(1,1) = Title
-language() = English
}
Does such a thing exist already?
A WTDI exists already:
for ( $XL-{Application}-{ActiveSheet} ) {
$_-cells(1,1) = Title;
$_-language() = English;
}
(presuming lvalue-methods, of course...)
--
John Porter
Re: aliasing - was:[nice2haveit]
On Wed, 18 Jul 2001 09:00:25 -0400, John Porter wrote:
Does such a thing exist already?
A WTDI exists already:
for ( $XL-{Application}-{ActiveSheet} ) {
$_-cells(1,1) = Title;
$_-language() = English;
}
(presuming lvalue-methods, of course...)
So, in this case, a with synonym for for would work.
But this only works for scalars. You can't have a %foo alias to
%Some::Other::hash this way, or a @bar alias to @Some::Other::array.
--
Bart.
Re: aliasing - was:[nice2haveit]
Bart Lateur wrote:
On Wed, 18 Jul 2001 09:00:25 -0400, John Porter wrote:
for ( $XL-{Application}-{ActiveSheet} ) {
$_-cells(1,1) = Title;
$_-language() = English;
}
(presuming lvalue-methods, of course...)
So, in this case, a with synonym for for would work.
Particularly if '$_' was implied... So with Perl 6's '.' replacing '-',
and 'with' aliasing 'for':
with ( $XL.{Application}.{ActiveSheet} ) {
.cells(1,1) = Title;
.language() = English;
}
Heh. That is nice and compact... although it's getting hard to tell it
apart from VB ;-)
--
Jeremy Howard
[EMAIL PROTECTED]
Re: aliasing - was:[nice2haveit]
Does such a thing exist already?
A WTDI exists already:
for ( $XL-{Application}-{ActiveSheet} ) {
$_-cells(1,1) = Title;
$_-language() = English;
}
(presuming lvalue-methods, of course...)
So, in this case, a with synonym for for would work.
]- OR
with alias for;
with ( $XL-{Application}-{ActiveSheet} ) {
$_-cells(1,1) = Title;
$_-language() = English;
}
:)
=
iVAN
[EMAIL PROTECTED]
=
Re: aliasing - was:[nice2haveit]
So, in this case, a with synonym for for would work.
Particularly if '$_' was implied... So with Perl 6's '.' replacing '-',
and 'with' aliasing 'for':
with ( $XL.{Application}.{ActiveSheet} ) {
.cells(1,1) = Title;
.language() = English;
}
This is my idea for it; .zebra could always be the 'default variables'
attribute 'zebra'. The With could also make the [variable, alias, whatever]
default, but not replace the $_:
$_ = monkey ;
$foo = coward;
with ($foo){
print;
print $_;
}
would output monkey coward. If this was univeral and heirachial, then
$foo.bar.quux = chainsaw;
with ($foo){
with (.bar){
print .quux;
}
}
I see a problem with . being the old way of sticking strings together
though.
(All opinions expressed in this post are probably wrong.)
Re: aliasing - was:[nice2haveit]
So, in this case, a with synonym for for would work.
Particularly if '$_' was implied... So with Perl 6's '.' replacing '-',
and 'with' aliasing 'for':
with ( $XL.{Application}.{ActiveSheet} ) {
.cells(1,1) = Title;
.language() = English;
}
This is my idea for it; .zebra could always be the 'default variables'
attribute 'zebra'. The With could also make the [variable, alias, whatever]
default, but not replace the $_:
$_ = monkey ;
$foo = coward;
with ($foo){
print;
print $_;
}
would output monkey coward. If this was universal and heirachial, then
$foo.bar.quux = chainsaw;
with ($foo){
with (.bar){
print .quux;
}
}
Be cool if this could be overloaded (correct word?) to work for functions,
too.
with (print()){
foo;
monkey;
}
I see a problem with . being the old way of sticking strings together
though.
(All opinions expressed in this post are probably wrong. Trying to figure
how to post this thing, the newsgroup bit didn't work.)
Re: aliasing - was:[nice2haveit]
I mean something like this :
instead of :
#$Request-{Params}
local *myhash = \%{$$Request{Params}};
my %myhash alias %{$$Request{Params}};#see - it is my (now as far as I
know
u can't have it 'my')
You don't need a typeglob there; you can do the following, which does
work
with 'my':
my %myhash = %{$Request-{Params}};
Originally he wanted an alias, and that won't do it. You'll flatten and
unflatten, and changes to %myhash won't be reflected in the original.
]- that's right ... and it is not very good if the HASH is big ... and what
to say if it is tied to DBM, even slower
the idea of aliasing is to preserve the fast access and on the other side to
shorden the accessor(i.e the way to access the structure) and make code
clearer.(mostly u can choose a name that has better meaning in your context)
Also if we talk about object methods it many times good to have many methods
do the same thing.. say (just examples, don't blame me just throwing what
comes in my mind):
get alias Obj::getAttribute
set alias Obj::setAttribute
setAttr alias Obj::setAttribute
oldObj::myOldBrokenMethod alias Obj::myBrandNewMethod ; #backward
compatibility
mypop alias pop;#core func aliasing
$flag alias
$My::Very::Hairy::Object::Which::Is::Very::Hard::To::Access::flag
:)
=
iVAN
[EMAIL PROTECTED]
=
Re: aliasing - was:[nice2haveit]
raptor [EMAIL PROTECTED] wrote:
...
the idea of aliasing is to preserve the fast access and on the other side
to
shorden the accessor(i.e the way to access the structure) and make code
clearer.(mostly u can choose a name that has better meaning in your
context)
This reminds me... another way to to shorten the accessor discussed in the
RFC process was something like Delphi VB's 'with' syntax:
VB
with Application.ActiveSheet
.cells(1,1) = Title
.language = English
end with
Application.ActiveSheet.cells(2,1) = Slow way
/VB
I can't remember if this actually found its way into an RFC--anyone have a
reference? I could envisage this prototyped in P5 with a source filter to
deal with a syntax like this:
Pseudo-Perl
with $XL-{Application}-{ActiveSheet} {
-cells(1,1) = Title
-language() = English
}
/Pseudo-Perl
Does such a thing exist already?
