“Nothing is more fairly distributed than common sense: no one thinks
he needs more of it than he already has.”
– René Descartes
This module implements some sane defaults for Perl programs, as defined by
two typical (or not so typical - use your common sense) specimens of Perl
coders. In fact, after working out details on which warnings and strict
modes to enable and make fatal, we found that we (and our code written so
far, and others) fully agree on every option, even though we never used
warnings before, so it seems this module indeed reflects a "common" sense
among some long-time Perl coders.
The basic philosophy behind the choices made in common::sense can be
summarised as: "enforcing strict policies to catch as many bugs as
possible, while at the same time, not limiting the expressive power
available to the programmer".
Two typical examples of how this philosophy is applied in practise is the
handling of uninitialised and malloc warnings:
'undef' is a well-defined feature of perl, and enabling warnings for
using it rarely catches any bugs, but considerably limits you in what you
can do, so uninitialised warnings are disabled.
Freeing something twice on the C level is a serious bug, usually causing
memory corruption. It often leads to side effects much later in the
program and there are no advantages to not reporting this, so malloc
warnings are fatal by default.
Unfortunately, there is no fine-grained warning control in perl, so often
whole groups of useful warnings had to be excluded because of a single
useless warning (for example, perl puts an arbitrary limit on the length of
text you can match with some regexes before emitting a warning, making the
whole 'regexp' category useless).
What follows is a more thorough discussion of what this module does, and
why it does it, and what the advantages (and disadvantages) of this