Higher-Order Perl

CHAPTER 9 DECLARATIVE PROGRAMMING

Beginning programmers often wish for a way to simply tell the computer what they want, and have the computer figure out how to do it. Declarative programming is an attempt to do that. The idea is that the programmer will put in the specifications for the value to be computed, and the computer will use the appropriate algorithm.

Nobody knows how to do this in general, and it may turn out to be impossible. But there are some interesting results we can get in specific problem domains. Regular expressions are a highly successful example of declarative programming. You write a pattern that represents the form of the text you are looking for, and then sit back and let the regex engine figure out the best way of locating ...