Mastering Regular Expressions (2nd Edition) [Electronic resources] نسخه متنی

7.1 Regular Expressions as a Language Component

An attractive feature of Perl is that regex support is so deftly built in as part of the
language. Rather than providing stand-alone functions for applying regular expressions,
Perl provides regular-expression operators that are meshed well with the
rich set of other operators and constructs that make up the Perl language.

With as much regex-wielding power as Perl has, one might think that it's over-
flowing with different operators and such, but actually, Perl provides only four
regex-related operators, and a small handful of related items, shown in
Table 7-1.

Perl is extremely powerful, but all that power in such a small set of operators can
be a dual-edged sword.

7.1.1 Perl's Greatest Strength

The richness of variety and options among Perl's operators and functions is perhaps
its greatest feature. They can change their behavior depending on the context
in which they're used, often doing just what the author naturally intends in each
differing situation. In fact, O'Reilly's Programming Perl goes so far as to boldly
state "In general, Perl operators do exactly what you want...." The regex match
operator m/
regex
/, for example, offers an amazing variety of different functionality depending upon where, how, and with which modifiers it is used.

7.1.2 Perl's Greatest Weakness

This concentrated richness in expressive power is also one of Perl's least-attractive
features. There are innumerable special cases, conditions, and contexts that seem
to change out from under you without warning when you make a subtle change
in your codeyou've just hit another special case you weren't aware of.[2]
The Programming
Perl quote in the previous paragraph continues "...unless you want
consistency." Certainly, when it comes to computer science, there is a certain
appreciation to boring, consistent, dependable interfaces. Perl's power can be a
devastating weapon in the hands of a skilled user, but it sometimes seems with
Perl, you become skilled by repeatedly shooting yourself in the foot.

[2] That they're innumerable doesn't stop this chapter from trying to cover them all!