Re^2: searching for unique numbers into a string

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Re^3: searching for unique numbers into a string by Marshall (Canon) on Apr 07, 2009 at 17:14 UTC
Well this whole array vs list thing is filled with controversy. Tom Christiansen says things like @xyz is an array variable that defines a list, your faq reference not withstanding. I mean look at Tom's writings on the subject like this one: http://www.perl.com/doc/manual/html/pod/perllol.html. Or some of his books. I personally think this gets into what I would call "language lawyering" and fine parsing of the terminology and to no real benefit. I personally like the way Tom does it by introducing the term array and then quickly moving to calling all of these Perl equivalent things to "arrays in other langugages", lists. That a list is described by an array variable type, is not that an important distinction to me. When we get into more complex Perl structures like LoL (List of Lists), LoH (Lists of Hash), LoLoL (List of Lists of Lists), my opinion is that these are MUCH more descriptive than other types of terms. I guess part of this has to do with what somebody's programming background is. In the C world, a "traditional 2- D" or higher order C array is a pretty worthless data structure for most jobs. There are lots of problems with this, just one thing is that you have to pass around both dimensions which makes it very hard to write general purpose matrix routines. Also for example, I don't know of any traditional 2-D arrays used in the Unix O/S. Maybe there are some, I just don't know where they are. Starting with intermediate C, "traditional" 2-D C arrays go the way of the dodo bird. The way in C to build a practical 2D structure, say of ints is an **int (array of pointers to arrays of ints). This is very close to exactly what a Perl LoL is! In C, this is also a 2-D array, but it is a special kind of 2D array. In Perl, calling this a LoL, List of List (or more specifically List of references to Lists) is much more descriptive of what is really going on! A main point with a LoL is that everything is a pointer until you get to the final dimension. A "traditional" array has fixed memory layout and dimensions. That is not what a Perl list is! Any Perl list that has a name can be "grown". Even ones that are initialized with X number of elemements at the beginning of the program. I'm sure this post will generate some controversy. Maybe sometimes we get too caught up in yelling about terminology? I like the terms LoL, etc. If somebody wants to call this AoA, I'm not that bent out of shape about it. I think LoL is better, but this is not the "end of the world".	[reply]

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Re^3: searching for unique numbers into a string
by Marshall (Canon) on Apr 07, 2009 at 17:14 UTC

I personally think this gets into what I would call "language lawyering" and fine parsing of the terminology and to no real benefit. I personally like the way Tom does it by introducing the term array and then quickly moving to calling all of these Perl equivalent things to "arrays in other langugages", lists. That a list is described by an array variable type, is not that an important distinction to me.

When we get into more complex Perl structures like LoL (List of Lists), LoH (Lists of Hash), LoLoL (List of Lists of Lists), my opinion is that these are MUCH more descriptive than other types of terms. I guess part of this has to do with what somebody's programming background is.

In the C world, a "traditional 2- D" or higher order C array is a pretty worthless data structure for most jobs. There are lots of problems with this, just one thing is that you have to pass around both dimensions which makes it very hard to write general purpose matrix routines. Also for example, I don't know of any traditional 2-D arrays used in the Unix O/S. Maybe there are some, I just don't know where they are.

Starting with intermediate C, "traditional" 2-D C arrays go the way of the dodo bird. The way in C to build a practical 2D structure, say of ints is an **int (array of pointers to arrays of ints). This is very close to exactly what a Perl LoL is! In C, this is also a 2-D array, but it is a special kind of 2D array. In Perl, calling this a LoL, List of List (or more specifically List of references to Lists) is much more descriptive of what is really going on! A main point with a LoL is that everything is a pointer until you get to the final dimension. A "traditional" array has fixed memory layout and dimensions. That is not what a Perl list is!

Any Perl list that has a name can be "grown". Even ones that are initialized with X number of elemements at the beginning of the program.

I'm sure this post will generate some controversy. Maybe sometimes we get too caught up in yelling about terminology? I like the terms LoL, etc. If somebody wants to call this AoA, I'm not that bent out of shape about it. I think LoL is better, but this is not the "end of the world".

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