Higher-Order Perl : Transforming Programs with Programs

Non-Lisp programmers, I think, fundamentally misunderstand the appeal of Lisp, and why it is superior to other programming languages. Lisp is not superior because it offers higher order functions or any of the other things, it is superior because it does not get in the way: Lisp meets problems, rather than forcing problems to meet it. This book serves two purposes: on the one hand it helps Perl programmers to move the center of gravity of their solutions further away from Perl, and a bit closer to their problems (quite a bit closer, actually), and on the other it provides a good introduction to Perl for Lisp programmers, and for that it gets an effortless five stars. I suspect that it is maybe more successful for the second purpose than the first: a relaxed read for someone who knows what a closure is, but for someone who does not know what a closure is, most likely not a relaxed read. Further, anyone who masters the contents may find that his newly refined coding style is somewhat caviary to the general, something that would be a problem in any IT/ORG that I have experienced. Small quibbles: A Pratt Precedence parser might have fitted the discussion better than the recursive descent parser that is developed, and a deeper discussion of the ways that Perl nevertheless falls short of Lisp, instead of just a passing reference to Norvig's list, would actually have made the arguement stronger - for instance you cannot add a macro facility similar to that of Lisp to Perl, and you cannot add the general continuations available in Scheme (or the limited continuations that Graham, e.g., shows how to add to Common Lisp). In short, Higher Order Perl makes a good case for the the aesthetics of haiku, but one should understand that (in spite of what my cousin, Leontia Flynn, thinks) it is haiku written with a typewriter, not with a caligrapher's brush. P.S. One minor repeated irritation for me was the way the author, in spite of everything, insisted on emphasising how input functions should read input files one line at a time. This is a bizarre mindset holdover from the seventies, that is inconsistent with the general argument of the book: if you have a computer with hundreds of megabytes, or gigabytes, of core, then the efficient way to read a text file is not line by line, but in one go. Most Perl programmers were originally trained as C and Unix programmers, so the Perl programs that they write bear a strong resemblance to C programs. However, Perl incorporates many features that have their roots in other languages such as Lisp. These advanced features are not well understood and are rarely used by most Perl programmers, but they are very powerful. They can automate tasks in everyday programming that are difficult to solve in any other way. One of the most powerful of these techniques is writing functions that manufacture or modify other functions. For example, instead of writing ten similar functions, a programmer can write a general pattern or framework that can then create the functions as needed according to the pattern.For several years Mark Jason Dominus has worked to apply functional programming techniques to Perl. Now Mark brings these flexible programming methods that he has successfully taught in numerous tutorials and training sessions to a wider audience. This title introduces powerful programming methods new to most Perl programmers that were previously the domain of computer scientists. It gradually builds up confidence by describing techniques of progressive sophistication. It shows how to improve everyday programs and includes numerous engaging code examples to illustrate the methods. Most Perl programmers were originally trained as C and Unix programmers, so the Perl programs that they write bear a strong resemblance to C programs. However, Perl incorporates many features that have their roots in other languages such as Lisp. These advanced features are not well understood and are rarely used by most Perl programmers, but they are very powerful. They can automate tasks in everyday programming that are difficult to solve in any other way. One of the most powerful of these techniques is writing functions that manufacture or modify other functions. For example, instead of writing ten similar functions, a programmer can write a general pattern or framework that can then create the functions as needed according to the pattern. For several years Mark Jason Dominus has worked to apply functional programming techniques to Perl. Now Mark brings these flexible programming methods that he has successfully taught in numerous tutorials and training sessions to a wider audience.

* Introduces powerful programming methods—new to most Perl programmers—that were previously the domain of computer scientists
* Gradually builds up confidence by describing techniques of progressive sophistication
* Shows how to improve everyday programs and includes numerous engaging code examples to illustrate the methods This eagerly awaited book by one of the best-known Perl developers summarizes years of innovative practice Most Perl programmers were originally trained as C and Unix programmers, so the Perl programs that they write bear a strong resemblance to C programs. However, Perl incorporates many features that have their roots in other languages such as Lisp. These advanced features are not well understood and are rarely used by most Perl programmers, but they are very powerful. They can automate tasks in everyday programming that are difficult to solve in any other way. One of the most powerful of these techniques is writing functions that manufacture or modify other functions. For example, instead of writing ten similar functions, a programmer can write a general pattern or framework that can then create the functions as needed according to the pattern. For several years Mark Jason Dominus has worked to apply functional programming techniques to Perl. Now Mark brings these flexible programming methods that he has successfully taught in numerous tutorials and training sessions to a wider audience. Most Perl programmers, including the inventor of Perl, were originally trained as C and UNIX programmers. So the Perl programs that they write bear a strong resemblance to C programs. But Perl incorporates many features that have their roots in non-C programming languages such as LISP. These advanced features are not well understood and are rarely used by most Perl programmers, but they are very powerful. They can automate tasks in everyday programming that are difficult to solve any other way, and also serve as an introduction to the techniques of functional programming for those who have not Recursion and Callbacks Dispatch Tables Caching and Memoization Iterators From Recursion to Iterators Infinite Streams Higher-Order Functions and Currying Parsing Declarative Programming Until the release of Perl 5.6.0, there was no good way to generate a binary numeral in Perl.