Intermeditae Perl Review

redspike on 2010-03-05T10:34:59

Well after what seems like several decades I am finally going to Review 'Intermediate Perl by Randal L. Schwartz, brian d foy and Tom Phoenix. The book is on the whole very well written and has an amusing style which belies its importance. Initially I read Randal Schwartz and Tom Phoenix and brian d foy which gave me the basics, enough in fact to use some cgi scripts that, although now need a re-write to due my added knowledge, are still in use today.

I then went onto Programming Perl by Larry Wall, Tom Christiansen, Jon Orwant which I read as a sort of novel, when I told this to Larry Wall at a YAPC he said that it was mostly fiction anyway. It introduced me to alot of the advanced features in Perl but was a bit heavy going. After I had read it I wondered if there was something inbetween this and Learning Perl, something intermediate.

I know it seems obvious not but I did not look for a book called Intermediate Perl. I found this sort of pattern happening a lot in my jourmey through Perl, the obvious is so obvious I miss it. I have tried to start looking for the obvious before I hare off and look for the complicated and down right obscure which always seem more easy to see. As I had not cultivated the culture of 'The Bleeding Obvious' I bought a few others which, although good in their way were not really suitable at the time for where I was at. Eventually I got a copy of 'Intermediate Perl' and it all made more sense.

I read another review online which suggested a different order in which to read the chapters. The suggested thing was to read Ch 3 after reading Ch 10 and then read Ch 15 because it was thought that you need to know about modules after learning about building larger programs. This I did and it seemed to make more sense. Apart from my normal gripe about not explaining how to get help through Perldoc and a few examples which when typed in verbatum do not work (bottom of page 4 in particular its is not that it is wrong but to make it run you have to do a little more than is written) the book helped alot. This kind of thing is not a problem half way through the book, any book, a little assumed knowledge has been learned, but it is important to make things absolutey implicit in the first few examples. Implied knowledge is an easy way to dishearted anyone and could in extreme cases cause someone to give up. Reading it through at least twice meant that a few things clicked eventually and gave me a sense of achievement when I understood the concepts and put some of them to the test. The story of Gilligan, Skipper, The professor and crew meant a simple but powerful thread kept the example real. Although imagined, these examples explained in fairly simple terms some very complicated ideas that I found fairly easy to apply to real world applications. Having read 'Programming Perl' first meant that I had gone a long way to understanding many of the ideas but anyone going about it in the right order would have less of a virtical wall to look at when they got to the 'Camel'. I use Intermediate Perl as a reference at the moment and to re-read certain chapters when I have a quiet moment.

I would recommend this book to anyone who has just got through Learning Perl or who is coming to Perl from another language and wants to start in a comfortable place before scaling the heights.

Whilst reading the chapter on references I was struck by the one of the many lighthning strikes out of the snaffed and blurreddy that is 'The Bleeding Obvious'. It may be called a reference but I thought that that was just its name. Unlike a the fact that a variable is called a variable because its value can vary but not its declared name,(I know that that is not necessarily the case as it is its address in memory that does not change or perhaps something else that I don't know yet, but humour me) a reference is called a reference because it is a reference to some thing, usually a scalar, array, subroutine or hash or something. As a reference it refers to something. You cannot believe how I wondered how I had managed to get through at least 3 rather large books before it finally sank in. I am not sure if it was the fact I did not read the right books in the right order or the fact that I was not really reading what I was reading. Either way, I have had the same experience several times. I think that because it has always been pointed out that Larry Wall is a linguist and therefore has crafted Perl in a liguistic way that I assumed the opposite. I have the same experience with other languages and with other things too but that is part of the joys, or not, of not taking the obvious as obvious. Tell me one thing and I will often assume the opposite because that is what I thought you meant, and just when I think I have got it I will the think the opposite of the opposite which is of course the obvious but not everytime. Sounds dumb when you write it down but with everyone trying to be so damn clever I am not sure who is genuinely clever and who is trying to look clever by inference. In Larry's case I think he is just being genuine.

I will do a more indepth review of this book as it has helped me a great dealm but this will do to get started for now.