general issues about Perl

[wang]

Hi, I have several general language issues about Perl.
1. What goals did the designers of the Perl have in mind?
2. What IDE are available for Perl ?
3. Is Perl static-scoped or dynamic-scoped?
4. Is Perl strongly typed?
5.What parameter-passing modes does Perl support?
6. Does Perl support abstract data types?
7. What are the Perl's strengths?
8. What are the Perl's weakness?

Thanks!

 

[MikeLacey]

have a look at

http://www.perl.com

Mike
michael.j.lacey@ntlworld.com

 

[jimd1024]

Recently, events have conspired to force me to become a decent
perl programer. You should check

http://www.perl.com

for
answers to your questions, too.

Check Perl FAQs there, too.

There are some newsgroups with very knowledgable users.

My answers are a bit personal.


Answers to your questions below:

wang (Visitor)
Nov 21, 2000

Hi, I have several general language issues about Perl.
1. What goals did the designers of the Perl have in mind?

First, to become a very strong string/text processing language.
Second, to exceed all other UNIX scripting languages in power and ease.
Third, to leave the programmer with few formal restrictions.
Fourth, to become a strong general language.
Fifth, to occupy glue positions well.

I think it's done all of these.
.
2. What IDE are available for Perl ?

This is a weakness of perl. There are a few commercial products out
there, but none compare to Delphi-like products. There is a GUI
development system perl:TK which borrows the TK from Tcl:TK.
It lets you develop GUI applications on serveral OSs but it isn't an IDE.

3. Is Perl static-scoped or dynamic-scoped?

Both options are available in perl 5 with both 'my' and 'local' variables.

4. Is Perl strongly typed?

Perl is very weakly typed on the whole. The goal is to make
srting and arithmetic operations fluid and easy. The Perl programmer
spends almost no time in type conversion.

5.What parameter-passing modes does Perl support?

You pass a single array to a perl subroutine. The receiving routine needs to
know what each part is. You can effectively do any of passing method: value,
reference, or name. It leaves more to you and checks on less than other
languages. There is a prototype options for sub calls that will let you
effect some restrictions on sub cals

6. Does Perl support abstract data types?

Almost any but you have to provide much of the undlying work yourself.
One variable type is an associative array, it maps name, value pairs and
is very strong

7. What are the Perl's strengths?

1) Rapid development with a good ratio of progammer time in to work out.
Perl programmers say that a typical perl program will run 1/3 to 1/10
of the length of a similar C or C++ program.
2) A rich set of functions and structures. It is close to having "everything"
3) Excellent text processing . Almost certainly the best for this.
4) Close links to the World Wide Web, probably the most common web
language.
5) Strong set of modules available from other programmers to perform
common functions. Web, Databse connections, graphics, date and time
see cpan when you visit

http://www.perl.com

6) Has an eval function, so your program can write code, and execute it.
7) String operations are integral to the language not tack-ons this is an
advantage not just for text processing but for almost all work. Has the
strongest set of unix "regexs"
8) Includes a decent system for pointers (references) unusual in an
interpretated language
9) Support for OO basics, but you don't have to use them.
10) Very portable, Windows, unix, linux, Macintosh
11) A stong and active community
12) Will open up your creative side a little, doesn't over restrain the
programmer (also a disadvantage)
13) Very fast for an intrepreted language . Typically 3 - 10 times slower
than good C, but often as fast as C++ and faster than Java

8. What are the Perl's weakness?

1. No real IDE
2. If written poorly, it can be hard to read, people argue that some
perl code is "write only" , with decent practice, and comments this
isn't true, but it doesn't force you to do this.
3. The many features can make for a long learning curve, but you should
be productive well ahead of knowing all of what's available.

That's it I guess. I'm glad I picked it up.

Thanks!