Re: [nice2haveit]: transpose function
David L. Nicol [EMAIL PROTECTED] wrote: Yes, exactly. I would like to have a transpose operator, which will work on a list of hash refs, so this: $solids = [1..7]; $stripes = [9..15]; foreach (transpose($solids,$stripes)); print the $_-[0] ball is the same color as the $_-[1]\n; RFC 272 proposes a transpose function: http://dev.perl.org/rfc/272.html Also see the proposal for merge(): http://dev.perl.org/rfc/90.html
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]
=
one more nice2haveit
hi,
As I was programming i got again to one thing i alwas needed to have...
especialy when write something fast or debug some result... words comes
about for/foreach and accessing the current-index of the array I'm working
with i.e.
say I have two arrays @a and @b and want to print them (also say they are
connected in some way so I want to see them both). In case of one array I
write :
print $_\n for @a;
fast, simple, goodbut in my case I have to write something like this :
for ($i = 0; $i scalar @a; $i++) {
print $a[$i] : $b[$i]\n
};
I've go tired of typing :), but if I had current index-iterator ( say under
$i just as example) at hand the way I have $_ i can just type :
print $_ : $b[$i]\n for @a;
OR
print $a[$i] : $b[$i]\n for @a;
isn't that cute :) ... the same count for list in $i I just get current
position in the list. (we can also use pos in some way!!!)
print $_ : $a[$i] : $b[$i]\n for (qw(val1 val2 val3));
I need it very often.:)
don't bother if the lenght of both arrays are different when u use it, u
know what u are doing...
=
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: one more nice2haveit
How about
print $a[$_]:$b[$_] for 0..$#a;
or in the p6 case...
print @a[$_]:@b[$_] for 0..$#a;
Ilya
-Original Message-
From: raptor
To: [EMAIL PROTECTED]
Sent: 07/18/2001 12:14 PM
Subject: one more nice2haveit
hi,
As I was programming i got again to one thing i alwas needed to have...
especialy when write something fast or debug some result... words comes
about for/foreach and accessing the current-index of the array I'm
working
with i.e.
say I have two arrays @a and @b and want to print them (also say they
are
connected in some way so I want to see them both). In case of one array
I
write :
print $_\n for @a;
fast, simple, goodbut in my case I have to write something like this
:
for ($i = 0; $i scalar @a; $i++) {
print $a[$i] : $b[$i]\n
};
I've go tired of typing :), but if I had current index-iterator ( say
under
$i just as example) at hand the way I have $_ i can just type :
print $_ : $b[$i]\n for @a;
OR
print $a[$i] : $b[$i]\n for @a;
isn't that cute :) ... the same count for list in $i I just get current
position in the list. (we can also use pos in some way!!!)
print $_ : $a[$i] : $b[$i]\n for (qw(val1 val2 val3));
I need it very often.:)
don't bother if the lenght of both arrays are different when u use
it, u
know what u are doing...
=
iVAN
[EMAIL PROTECTED]
=
Re: one more nice2haveit
I've go tired of typing :), but if I had current index-iterator ( say under $i just as example) at hand the way I have $_ i can just type : print $_ : $b[$i]\n for @a; OR print $a[$i] : $b[$i]\n for @a; For a general solution to this see Buddha Buck's RFC on iterators: http://dev.perl.org/rfc/207.html -- Jeremy Howard [EMAIL PROTECTED]
Re: nice2haveit
Raptor [EMAIL PROTECTED] wrote:
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}};
or
my $hashref = $Request-{Params}; # neater, and I personally prefer
# working with
hashrefs
Less typing, and it's already in there. :)
Take care,
Mark.
Re: nice2haveit
At 05:10 AM 7/17/2001 +, Mark Morgan wrote:
Raptor [EMAIL PROTECTED] wrote:
I mean something like this :
instead of :
#$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 = %{$Request-{Params}};
Originally he wanted an alias, and that won't do it. You'll flatten and
unflatten, and changes to %myhash won't be reflected in the original.
Dan
--it's like this---
Dan Sugalski even samurai
[EMAIL PROTECTED] have teddy bears and even
teddy bears get drunk
Re: aliasing - was:[nice2haveit]
I mean something like this :
instead of :
#$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?
Re: nice2haveit
Uri Guttman wrote: one related point is that this symbol table will be accessible via caller() so you could access/install lexical symbols in a parent block on the call stack. scary! Quite. Does anyone have a pointer to tchrist's rant on Tcl's upvar? -- John Porter
Re: nice2haveit
At 03:37 PM 7/16/2001 -0500, David L. Nicol wrote: Uri Guttman wrote: one related point is that this symbol table will be accessible via caller() so you could access/install lexical symbols in a parent block on the call stack. scary! We must demand that the feature come with a way to seal the current context from manipulation, even possibly a way to block accesses. Demand away, but you're not likely to get it. Dan --it's like this--- Dan Sugalski even samurai [EMAIL PROTECTED] have teddy bears and even teddy bears get drunk
Re: nice2haveit
On Mon, Jul 16, 2001 at 03:37:41PM -0500, David L. Nicol wrote: Uri Guttman wrote: one related point is that this symbol table will be accessible via caller() so you could access/install lexical symbols in a parent block on the call stack. scary! uri We must demand that the feature come with a way to seal the current context from manipulation, even possibly a way to block accesses. Doesn't sound very Perlish to me. -- Paul Johnson - [EMAIL PROTECTED] http://www.pjcj.net
Re: nice2haveit
On Fri, 13 Jul 2001 20:55:07 +1000 (EST), Damian Conway wrote:
Would you like to clarify what you mean here.
Are you talking about typeglob assignments?
Perl 6 will have:
$Foo::{'$bar'} = \$baz; # Alias $Foo::bar to $baz
Are we back to globals only? What about lexical aliases? Something
like:
my \%foo = \%bar;
(Now %foo is an alias to %bar.)
--
Bart.
Re: nice2haveit
BL == Bart Lateur [EMAIL PROTECTED] writes:
BL On Fri, 13 Jul 2001 20:55:07 +1000 (EST), Damian Conway wrote:
Would you like to clarify what you mean here.
Are you talking about typeglob assignments?
Perl 6 will have:
$Foo::{'$bar'} = \$baz;# Alias $Foo::bar to $baz
BL Are we back to globals only? What about lexical aliases? Something
BL like:
BL my \%foo = \%bar;
BL (Now %foo is an alias to %bar.)
what damian has been showing as a possible/probably solution is a
lexical scoped symbol table called %MY::. it would be available inside
any block scope and allow you to alias things just like the above:
$MY::{'$bar'} = \$baz; # Alias lexical $bar to $baz
now $bar is lexical and aliased to $baz
i like the concept but i worry about the overhead of setting up %MY. i
assume it will only be created if it is referred to in the block. there
may be other optimizations.
one related point is that this symbol table will be accessible via
caller() so you could access/install lexical symbols in a parent block
on the call stack. scary!
uri
--
Uri Guttman - [EMAIL PROTECTED] -- http://www.sysarch.com
SYStems ARCHitecture and Stem Development -- http://www.stemsystems.com
Learn Advanced Object Oriented Perl from Damian Conway - Boston, July 10-11
Class and Registration info: http://www.sysarch.com/perl/OOP_class.html
Re: nice2haveit
$Foo::{'$bar'} = \$baz; # Alias $Foo::bar to $baz
Are we back to globals only? What about lexical aliases? Something
like:
my \%foo = \%bar;
I've always wondered why the backslash operator wasn't lvaluable. (IIRC, C++'s
operator is semi-lvaluable.) IM(V)HO this is a good idea--it certainly makes more
sense than $Foo::{'$bar'} = \$baz. Or wait, was that supposed to be %Foo::{'$bar'}?
:^) )
--
___
Get your free email from http://webmail.earthlink.net
nice2haveit
hi,
Two things i think is good to have it :
1. ALIAS keyword.
- first reason is 'cause many people don't know that this is possible.. at
least any newscommer and it will help not to forgot that it exist :).
- Code become more readable.
- can be Overloaded
- the syntax for aliasing can become reicher :)
2. Hash-reg-ex-slice
%hash{/\d*/}
instead of :
grep {/\d*/} keys %hash
%hash{/\d*/} = ();
%hash{/\d*/} = @list;# pump the @list values into %hash values (keys stay
the same)
- espesialy usefull with DBM
3. For this I'm not totaly sure, but it comes to my mind many modules
uses notation like this to pass params i.e.
someFunc ( -param1 = 'blah', param2 = 'xxx' .)
Why not have %_ in our case we have the following elements :
%_{'-param1'} = 'blah'
%_{'param2'} = 'xxx'
If in object/class contrext (can this be checked in some way) first element
goes to :
%_{self}
note : all references goes directly i.e. : my %_ = map { $_ unless ref }
@_;
Also there is no need the HASH to be generated until we use it for the first
time, for speedup !?! is this possible.
I think if it is not hard for implementation it is nice shortcut.
=
iVAN
[EMAIL PROTECTED]
=
Re: nice2haveit
Two things i think is good to have it :
1. ALIAS keyword.
- first reason is 'cause many people don't know that this is possible.. at
least any newscommer and it will help not to forgot that it exist :).
- Code become more readable.
- can be Overloaded
- the syntax for aliasing can become reicher :)
Would you like to clarify what you mean here.
Are you talking about typeglob assignments?
Perl 6 will have:
$Foo::{'$bar'} = \$baz; # Alias $Foo::bar to $baz
3. For this I'm not totaly sure, but it comes to my mind many modules
uses notation like this to pass params i.e.
someFunc ( -param1 = 'blah', param2 = 'xxx' .)
Why not have %_ in our case we have the following elements :
http://dev.perl.org/rfc/128.html#Named_arguments
Damian
Re: nice2haveit
Two things i think is good to have it :
1. ALIAS keyword.
- first reason is 'cause many people don't know that this is
possible.. at
least any newscommer and it will help not to forgot that it exist
:).
- Code become more readable.
- can be Overloaded
- the syntax for aliasing can become reicher :)
Would you like to clarify what you mean here.
Are you talking about typeglob assignments?
Perl 6 will have:
$Foo::{'$bar'} = \$baz; # Alias $Foo::bar to $baz
]- Can I see more examples of typeglob assignment somewhere ? link ?
I mean something like this :
instead of :
#$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')
=
iVAN
[EMAIL PROTECTED]
=
RE: nice2haveit
-Original Message-
From: raptor
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Sent: 7/13/01 10:19 AM
Subject: Re: nice2haveit
Two things i think is good to have it :
1. ALIAS keyword.
- first reason is 'cause many people don't know that this is
possible.. at
least any newscommer and it will help not to forgot that it exist
:).
- Code become more readable.
- can be Overloaded
- the syntax for aliasing can become reicher :)
Would you like to clarify what you mean here.
Are you talking about typeglob assignments?
Perl 6 will have:
$Foo::{'$bar'} = \$baz; # Alias $Foo::bar to $baz
]- Can I see more examples of typeglob assignment somewhere ? link ?
I mean something like this :
instead of :
#$Request-{Params}
local *myhash = \%{$$Request{Params}};
Wouldn't that do the same as
my $myhash = ($request{Params});
I know that is actually copying value, but I believe the above does too?
Ilya
my %myhash alias %{$$Request{Params}};#see - it is my (now as far as I
know
u can't have it 'my')
=
iVAN
[EMAIL PROTECTED]
=
Re: nice2haveit
At 09:24 PM 7/13/2001 +0300, raptor wrote:
in the case of :
local *myhash = \%{$Request-{Params}};
u do this :
print $myhash{abc};
so it is first clearer and second I hope much faster
Clearer maybe, faster probably not appreciably.
Regardless, the lexical 'symbol table' will be available to perl programs.
How is up in the air, but I've heard proposals that the virtual package MY
will refer to it.
We'll see, once Larry formalizes (or squashes) the idea.
Dan
--it's like this---
Dan Sugalski even samurai
[EMAIL PROTECTED] have teddy bears and even
teddy bears get drunk
RE: nice2haveit
Yes but can't the same be accomplished with...
my $myhash = (%{$Request-{Params}});
print $myhash{abc};
Though again it copies the structure, I don't see how dereferencing can be
unclear?
Ilya
-Original Message-
From: raptor
To: [EMAIL PROTECTED]; Sterin, Ilya
Sent: 7/13/01 12:24 PM
Subject: Re: nice2haveit
the structure is something like this :
$Request = {
Params = {
abc = 1,
ddd = 2
}
}
the idea is that U don't dereference i.e. :
my $myhash = ($Request-{Params});
if u want to use it U have to do this :
print $$myhash{abc}; #or if u preffer print $myhash-{abc}
in the case of :
local *myhash = \%{$Request-{Params}};
u do this :
print $myhash{abc};
so it is first clearer and second I hope much faster
=
iVAN
[EMAIL PROTECTED]
=
Re: nice2haveit
Yes but can't the same be accomplished with...
my $myhash = (%{$Request-{Params}});
print $myhash{abc};
Though again it copies the structure, I don't see how dereferencing can be
unclear?
]- if u have someting like this anything u can remove in some way is worth
it:))
$tables{$$self{rel}{$k}{table}}[0][VALS]
or this :
$$params{$$self{rel}{$k}{names}[$t].$j}
especialy if U have a couple of this :) in 3-4 rows of code...
=
iVAN
[EMAIL PROTECTED]
=
