Why use Perl when we've got Python?!

[Sam Holden]

On Sat, 14 Aug 1999 03:08:33 GMT,
    John Stevens <jstevens at bamboo.verinet.com> wrote:
>On 14 Aug 1999 02:32:12 GMT, Sam Holden <sholden at pgrad.cs.usyd.edu.au> wrote:
>>On 13 Aug 1999 20:04:03 -0700,
    John W. Stevens <jstevens at basho.fc.hp.com> wrote:
>>>
>>>Perl doesn't have lists.  Python doesn't have built-in arrays.
>>
>>You should learn some perl you now..
>>
>>@array = (1,10,20,30);
>>$from_list = (1,10,20,30);
>>$from_array = @array;
>>print "$from_list\n$from_array\n";
>>
>>Will output :
>>30
>>4
>
>The @ prefix denotes an array.  You, yourself, should learn
>Perl.  Calling an array a list, doesn't make it one.

Can you read?

Can you see a @ in the following line of code :

$from_list = (1,10,20,30);

No you can't.  Is there an array in that line of code? No. Is there a list
in that line of code? Yes. Do lists and arrays behave differently? Yes, just
look at the different outputs.

>
>>Perl has lists,
>
>Not built in, it doesn't, unless you define array and list as being
>different words for exactly the same type/class.

I don't think you can get more built in then perl lists.

Again I repeat, here is a perl list : ('a', 'b', 'c') or qw(a b c)

>
>>if you know perl you would know this.
>
>I know Perl.  You need to learn Python.

Did I mention a single bit of python syntax in my post? No. 
Was I discussing python syntax? No.
Do you know if I use python? No.
Do you know if I like python? No.
Do you know if I have already spent time learning python?
Do you know if I am currently learning python?

What was the point of saying I need to learn Python? I wasn't saying python
was worse than perl, I wasn't saying python syntax is strange, I wasn't
talking about python. You might as well have told me to learn C or Lisp.

At least Lisp would be more relevant than python, if you were trying to
tell me to learn about lists in some strange abstract way.

Have I questioned your python knowledge? No.
Have I questioned your perl knowledeg? Yes, but only because you have
consistantly made basic mistakes when speaking about perl.

>
>>If you program in perl 
>>and don't know this, then you must get very very confused at times.
>
>If @ denotes list, then the following Perl would be illegal:
>
>@ary = (1, 2, 3);
>@ary[5] = "Test";
>
>But, obviously, this is not illegal.

@ary[5] is an array slice. It is an array. It happens to be an array 
that constists of only one element. Why would it be illegal? It is just
the special case of :

@ary[1,2,3,4,5,10,20]

It is an array. Thus it has a @.

Used like that it is almost a sure indication of an error by the programmer,
because a single element array slice has no benefit over the simple
array element in that context.

>
>>>I will assume that a list module is available for Perl.
>>
>>No it is one of the built in bits... like hashes and arrays.
>
>Really?  What is the prefix character that denotes a list?

You can't have a list in a variable. Lists in perl are constant. So
what would be the use of putting them in a _variable_. Just because there
is no list variable does not mean there are no lists. Again here is a list :

(1,2,3,4,5,6,7,8)

>
>>>I wasn't trying to compare features, I was simply pointing out
>>>that your comparison was Apples and Oranges, and therefore at
>>>least somewhat invalid.
>>
>>Only because you have no idea what you are talking about.
>
>:-)
>
>Coming from somebody who doesn't know the difference from *EMULATING*
>a list with an array, vs. a real array, that is a good one!

Again here is a list :

(1,2,3,4,5,6,7,8)

That is not an array. It is a list. It is different from an array. I already
showed how assigning to a scalar gives different results for lists and arrays,
here are some more differences :

push( (1,2,3,4,5), 6); 

This results in an error message, funnily enough the message is :
Type of arg 1 to push must be an array (not list)

Still claim perl has no lists? Of course you know better then perl itself.

@array = (1,2,3,4,5);
push(@array,6);

That works fine, because we are passing an array to push not a list.

Pop is the same :

pop (1,2,3,4,5);

Is an error (the message is as above s/push/pop/)

@array = (1,2,3,4,5);
pop @array;

Is legal and pops the 5 off @array.

>
>Now I suppose that you will tell me that Perl has stacks, too!
>;->

No it doesn't. 

-- 
Sam

why can't newbies use hash slices in their hello world programs? :-)
	-- Uri Guttman in <x74skxhve5.fsf at home.sysarch.com>