common-sense/sense.pm.PL

#! perl

open STDOUT, ">$ARGV[0]~"
   or die "$ARGV[0]~: $!";

our $WARN;
our $H;

BEGIN {
   $H    = $^H;
   $WARN = ${^WARNING_BITS};
}

use utf8;
use strict qw(subs vars);

no warnings;
use warnings qw(FATAL closed threads internal debugging pack malloc portable prototype
                inplace io pipe unpack regexp deprecated glob digit printf
                layer reserved taint closure semicolon);
no warnings qw(exec newline unopened);

BEGIN {
   $H    = $^H              & ~$H;
   $WARN = ${^WARNING_BITS} & ~$WARN;
}

while (<DATA>) {
   if (/^IMPORT/) {
      print "   # use warnings\n";
      printf "   \${^WARNING_BITS} ^= \${^WARNING_BITS} ^ \"%s\";\n",
             join "", map "\\x$_", unpack "(H2)*", $WARN;
      print "   # use strict, use utf8;\n";
      printf "   \$^H |= 0x%x;\n", $H;
   } else {
      print;
   }
}

close STDOUT;
rename "$ARGV[0]~", $ARGV[0];

__DATA__

=head1 NAME

common::sense - save a tree AND a kitten, use common::sense!

=head1 SYNOPSIS

 use common::sense;

 # supposed to be the same, with much lower memory usage, as:
 #
 # use utf8;
 # use strict qw(vars subs);
 # use feature qw(say state switch);
 # no warnings;
 # use warnings qw(FATAL closed threads internal debugging pack malloc
 #                 portable prototype inplace io pipe unpack regexp
 #                 deprecated glob digit printf layer
 #                 reserved taint closure semicolon);
 # no warnings qw(exec newline unopened);


=head1 DESCRIPTION

   “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:

=over 4

=item I<uninitialised>

C<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.

=item I<malloc>

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.

=back

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
approach are.

=head1 RATIONALE

=over 4

=item use utf8

While it's not common sense to write your programs in UTF-8, it's quickly
becoming the most common encoding, is the designated future default
encoding for perl sources, and the most convenient encoding available
(you can do really nice quoting tricks...). Experience has shown that our
programs were either all pure ascii or utf-8, both of which will stay the
same.

There are few drawbacks to enabling UTF-8 source code by default (mainly
some speed hits due to bugs in older versions of perl), so this module
enables UTF-8 source code encoding by default.


=item use strict qw(subs vars)

Using C<use strict> is definitely common sense, but C<use strict
'refs'> definitely overshoots its usefulness. After almost two
decades of Perl hacking, we decided that it does more harm than being
useful. Specifically, constructs like these:

   @{ $var->[0] }

Must be written like this (or similarly), when C<use strict 'refs'> is in
scope, and C<$var> can legally be C<undef>:

   @{ $var->[0] || [] }

This is annoying, and doesn't shield against obvious mistakes such as
using C<"">, so one would even have to write (at least for the time
being):

   @{ defined $var->[0] ? $var->[0] : [] }

... which nobody with a bit of common sense would consider
writing: clear code is clearly something else.

Curiously enough, sometimes perl is not so strict, as this works even with
C<use strict> in scope:

   for (@{ $var->[0] }) { ...

If that isn't hypocrisy! And all that from a mere program!


=item use feature qw(say state given)

We found it annoying that we always have to enable extra features. If
something breaks because it didn't anticipate future changes, so be
it. 5.10 broke almost all our XS modules and nobody cared either (or at
least I know of nobody who really complained about gratuitous changes -
as opposed to bugs).

Few modules that are not actively maintained work with newer versions of
Perl, regardless of use feature or not, so a new major perl release means
changes to many modules - new keywords are just the tip of the iceberg.

If your code isn't alive, it's dead, Jim - be an active maintainer.

But nobody forces you to use those extra features in modules meant for
older versions of perl - common::sense of course works there as well.
There is also an important other mode where having additional features by
default is useful: commandline hacks and internal use scripts: See "much
reduced typing", below.


=item no warnings, but a lot of new errors

Ah, the dreaded warnings. Even worse, the horribly dreaded C<-w>
switch: Even though we don't care if other people use warnings (and
certainly there are useful ones), a lot of warnings simply go against the
spirit of Perl.

Most prominently, the warnings related to C<undef>. There is nothing wrong
with C<undef>: it has well-defined semantics, it is useful, and spitting
out warnings you never asked for is just evil.

The result was that every one of our modules did C<no warnings> in the
past, to avoid somebody accidentally using and forcing his bad standards
on our code. Of course, this switched off all warnings, even the useful
ones. Not a good situation. Really, the C<-w> switch should only enable
warnings for the main program only.

Funnily enough, L<perllexwarn> explicitly mentions C<-w> (and not in a
favourable way, calling it outright "wrong"), but standard utilities, such
as L<prove>, or MakeMaker when running C<make test>, still enable them
blindly.

For version 2 of common::sense, we finally sat down a few hours and went
through I<every single warning message>, identifiying - according to
common sense - all the useful ones.

This resulted in the rather impressive list in the SYNOPSIS. When we
weren't sure, we didn't include the warning, so the list might grow in
the future (we might have made a mistake, too, so the list might shrink
as well).

Note the presence of C<FATAL> in the list: we do not think that the
conditions caught by these warnings are worthy of a warning, we I<insist>
that they are worthy of I<stopping> your program, I<instantly>. They are
I<bugs>!

Therefore we consider C<common::sense> to be much stricter than C<use
warnings>, which is good if you are into strict things (we are not,
actually, but these things tend to be subjective).

After deciding on the list, we ran the module against all of our code that
uses C<common::sense> (that is almost all of our code), and found only one
occurence where one of them caused a problem: one of elmex's (unreleased)
modules contained:

   $fmt =~ s/([^\s\[]*)\[( [^\]]* )\]/\x0$1\x1$2\x0/xgo;

We quickly agreed that indeed the code should be changed, even though it
happened to do the right thing when the warning was switched off.


=item much reduced typing

Especially with version 2.0 of common::sense, the amount of boilerplate
code you need to add to gte I<this> policy is daunting. Nobody would write
this out in throwaway scripts, commandline hacks or in quick internal-use
scripts.

By using common::sense you get a defined set of policies (ours, but maybe
yours, too, if you accept them), and they are easy to apply to your
scripts: typing C<use common::sense;> is even shorter than C<use warnings;
use strict; use feature ...>.

And you can immediately use the features of your installed perl, which
is more difficult in code you release, but not usually an issue for
internal-use code (downgrades of your production perl should be rare,
right?).


=item mucho reduced memory usage

Just using all those pragmas mentioned in the SYNOPSIS together wastes
<blink>I<< B<776> kilobytes >></blink> of precious memory in my perl, for
I<every single perl process using our code>, which on our machines, is a
lot. In comparison, this module only uses I<< B<four> >> kilobytes (I even
had to write it out so it looks like more) of memory on the same platform.

The money/time/effort/electricity invested in these gigabytes (probably
petabytes globally!) of wasted memory could easily save 42 trees, and a
kitten!

Unfortunately, until everybods applies more common sense, there will still
often be modules that pull in the monster pragmas. But one can hope...

=cut

package common::sense;

our $VERSION = '3.3';

# overload should be included

sub import {
IMPORT
   # use feature
   $^H{feature_switch} =
   $^H{feature_say}    =
   $^H{feature_state}  = 1;
}

1;

=back

=head1 THERE IS NO 'no common::sense'!!!! !!!! !!

This module doesn't offer an unimport. First of all, it wastes even more
memory, second, and more importantly, who with even a bit of common sense
would want no common sense?

=head1 STABILITY AND FUTURE VERSIONS

Future versions might change just about everything in this module. We
might test our modules and upload new ones working with newer versions of
this module, and leave you standing in the rain because we didn't tell
you. In fact, we did so when switching from 1.0 to 2.0, which enabled gobs
of warnings, and made them FATAL on top.

Maybe we will load some nifty modules that try to emulate C<say> or so
with perls older than 5.10 (this module, of course, should work with older
perl versions - supporting 5.8 for example is just common sense at this
time. Maybe not in the future, but of course you can trust our common
sense to be consistent with, uhm, our opinion).

=head1 WHAT OTHER PEOPLE HAD TO SAY ABOUT THIS MODULE

apeiron

   "... wow"
   "I hope common::sense is a joke."

crab

   "i wonder how it would be if joerg schilling wrote perl modules."

Adam Kennedy

   "Very interesting, efficient, and potentially something I'd use all the time."
   [...]
   "So no common::sense for me, alas."

H.Merijn Brand

   "Just one more reason to drop JSON::XS from my distribution list"

Pista Palo

   "Something in short supply these days..."

Steffen Schwigon

   "This module is quite for sure *not* just a repetition of all the other
   'use strict, use warnings'-approaches, and it's also not the opposite.
   [...] And for its chosen middle-way it's also not the worst name ever.
   And everything is documented."

BKB

   "[Deleted - thanks to Steffen Schwigon for pointing out this review was
   in error.]"

Somni

   "the arrogance of the guy"
   "I swear he tacked somenoe else's name onto the module
   just so he could use the royal 'we' in the documentation"

Anonymous Monk

   "You just gotta love this thing, its got META.json!!!"

dngor

   "Heh.  '"<elmex at ta-sa.org>"'  The quotes are semantic
   distancing from that e-mail address."

Jerad Pierce

   "Awful name (not a proper pragma), and the SYNOPSIS doesn't tell you
   anything either. Nor is it clear what features have to do with "common
   sense" or discipline."

acme

   "THERE IS NO 'no common::sense'!!!! !!!! !!"

apeiron (meta-comment about us commenting^Wquoting his comment)

   "How about quoting this: get a clue, you fucktarded amoeba."

quanth

   "common sense is beautiful, json::xs is fast, Anyevent, EV are fast and
   furious. I love mlehmannware ;)"

apeiron

   "... it's mlehmann's view of what common sense is. His view of common
   sense is certainly uncommon, insofar as anyone with a clue disagrees
   with him."

apeiron (another meta-comment)

   "apeiron wonders if his little informant is here to steal more quotes"

ew73

   "... I never got past the SYNOPSIS before calling it shit."
   [...]
   How come no one ever quotes me. :("

=head1 FREQUENTLY ASKED QUESTIONS

Or frequently-come-up confusions.

=over 4

=item Is this module meant to be serious?

Yes, we would have put it under the C<Acme::> namespace otherwise.

=item But the manpage is written in a funny/stupid/... way?

This was meant to make it clear that our common sense is a subjective
thing and other people can use their own notions, taking the steam out
of anybody who might be offended (as some people are always offended no
matter what you do).

This was a failure.

But we hope the manpage still is somewhat entertaining even though it
explains boring rationale.

=item Why do you impose your conventions on my code?

For some reason people keep thinking that C<common::sense> imposes
process-wide limits, even though the SYNOPSIS makes it clear that it works
like other similar modules - i.e. only within the scope that C<use>s them.

So, no, we don't - nobody is forced to use this module, and using a module
that relies on common::sense does not impose anything on you.

=item Why do you think only your notion of common::sense is valid?

Well, we don't, and have clearly written this in the documentation to
every single release. We were just faster than anybody else w.r.t. to
grabbing the namespace.

=item But everybody knows that you have to use strict and use warnings,
why do you disable them?

Well, we don't do this either - we selectively disagree with the
usefulness of some warnings over others. This module is aimed at
experienced Perl programmers, not people migrating from other languages
who might be surprised about stuff such as C<undef>. On the other hand,
this does not exclude the usefulness of this module for total newbies, due
to its strictness in enforcing policy, while at the same time not limiting
the expresive power of perl.

This module is considerably I<more> strict than the canonical C<use
strict; use warnings>, as it makes all its warnings fatal in nature, so
you can not get away with as many things as with the canonical approach.

This was not implemented in version 1.0 because of the daunting number
of warning categories and the difficulty in getting exactly the set of
warnings you wish (i.e. look at the SYNOPSIS in how complicated it is to
get a specific set of warnings - it is not reasonable to put this into
every module, the maintenance effort would be enourmous).

=item But many modules C<use strict> or C<use warnings>, so the memory
savings do not apply?

I suddenly feel sad...

But yes, that's true. Fortunately C<common::sense> still uses only a
miniscule amount of RAM.

=item But it adds another dependency to your modules!

It's a fact, yeah. But it's trivial to install, most popular modules have
many more dependencies and we consider dependencies a good thing - it
leads to better APIs, more thought about interworking of modules and so
on.

=item Why do you use JSON and not YAML for your META.yml?

This is not true - YAML supports a large subset of JSON, and this subset
is what META.yml is written in, so it would be correct to say "the
META.yml is written in a common subset of YAML and JSON".

The META.yml follows the YAML, JSON and META.yml specifications, and is
correctly parsed by CPAN, so if you have trouble with it, the problem is
likely on your side.

=item But! But!

Yeah, we know.

=back

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

 Robin Redeker, "<elmex at ta-sa.org>".

=cut

Revision:	1.6
Committed:	Fri Jul 2 20:43:05 2010 UTC (13 years, 10 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-3_3
Changes since 1.5:	+3 -3 lines
Log Message:	3.3
#	User	Rev	Content
1	root	1.1	#! perl
2
3			open STDOUT, ">$ARGV[0]~"
4			or die "$ARGV[0]~: $!";
5
6			our $WARN;
7			our $H;
8
9			BEGIN {
10			$H = $^H;
11			$WARN = ${^WARNING_BITS};
12			}
13
14			use utf8;
15			use strict qw(subs vars);
16
17			no warnings;
18	root	1.4	use warnings qw(FATAL closed threads internal debugging pack malloc portable prototype
19	root	1.6	inplace io pipe unpack regexp deprecated glob digit printf
20	root	1.2	layer reserved taint closure semicolon);
21	root	1.1	no warnings qw(exec newline unopened);
22
23			BEGIN {
24			$H = $^H & ~$H;
25			$WARN = ${^WARNING_BITS} & ~$WARN;
26			}
27
28			while (<DATA>) {
29			if (/^IMPORT/) {
30			print " # use warnings\n";
31			printf " \${^WARNING_BITS} ^= \${^WARNING_BITS} ^ \"%s\";\n",
32			join "", map "\\x$_", unpack "(H2)*", $WARN;
33			print " # use strict, use utf8;\n";
34			printf " \$^H \|= 0x%x;\n", $H;
35			} else {
36			print;
37			}
38			}
39
40			close STDOUT;
41			rename "$ARGV[0]~", $ARGV[0];
42
43			__DATA__
44
45			=head1 NAME
46
47			common::sense - save a tree AND a kitten, use common::sense!
48
49			=head1 SYNOPSIS
50
51			use common::sense;
52
53			# supposed to be the same, with much lower memory usage, as:
54			#
55			# use utf8;
56			# use strict qw(vars subs);
57			# use feature qw(say state switch);
58			# no warnings;
59	root	1.4	# use warnings qw(FATAL closed threads internal debugging pack malloc
60	root	1.1	# portable prototype inplace io pipe unpack regexp
61	root	1.6	# deprecated glob digit printf layer
62	root	1.2	# reserved taint closure semicolon);
63	root	1.1	# no warnings qw(exec newline unopened);
64
65	root	1.5
66	root	1.1	=head1 DESCRIPTION
67
68	root	1.5	“Nothing is more fairly distributed than common sense: no one thinks
69			he needs more of it than he already has.”
70
71			– René Descartes
72
73	root	1.1	This module implements some sane defaults for Perl programs, as defined by
74			two typical (or not so typical - use your common sense) specimens of Perl
75			coders. In fact, after working out details on which warnings and strict
76			modes to enable and make fatal, we found that we (and our code written so
77			far, and others) fully agree on every option, even though we never used
78			warnings before, so it seems this module indeed reflects a "common" sense
79			among some long-time Perl coders.
80
81			The basic philosophy behind the choices made in common::sense can be
82			summarised as: "enforcing strict policies to catch as many bugs as
83			possible, while at the same time, not limiting the expressive power
84			available to the programmer".
85
86			Two typical examples of how this philosophy is applied in practise is the
87			handling of uninitialised and malloc warnings:
88
89			=over 4
90
91			=item I<uninitialised>
92
93			C<undef> is a well-defined feature of perl, and enabling warnings for
94			using it rarely catches any bugs, but considerably limits you in what you
95			can do, so uninitialised warnings are disabled.
96
97			=item I<malloc>
98
99			Freeing something twice on the C level is a serious bug, usually causing
100			memory corruption. It often leads to side effects much later in the
101			program and there are no advantages to not reporting this, so malloc
102			warnings are fatal by default.
103
104			=back
105
106			What follows is a more thorough discussion of what this module does,
107			and why it does it, and what the advantages (and disadvantages) of this
108			approach are.
109
110			=head1 RATIONALE
111
112			=over 4
113
114			=item use utf8
115
116			While it's not common sense to write your programs in UTF-8, it's quickly
117			becoming the most common encoding, is the designated future default
118			encoding for perl sources, and the most convenient encoding available
119			(you can do really nice quoting tricks...). Experience has shown that our
120			programs were either all pure ascii or utf-8, both of which will stay the
121			same.
122
123			There are few drawbacks to enabling UTF-8 source code by default (mainly
124			some speed hits due to bugs in older versions of perl), so this module
125			enables UTF-8 source code encoding by default.
126
127
128			=item use strict qw(subs vars)
129
130			Using C<use strict> is definitely common sense, but C<use strict
131			'refs'> definitely overshoots its usefulness. After almost two
132			decades of Perl hacking, we decided that it does more harm than being
133			useful. Specifically, constructs like these:
134
135			@{ $var->[0] }
136
137			Must be written like this (or similarly), when C<use strict 'refs'> is in
138			scope, and C<$var> can legally be C<undef>:
139
140			@{ $var->[0] \|\| [] }
141
142			This is annoying, and doesn't shield against obvious mistakes such as
143			using C<"">, so one would even have to write (at least for the time
144			being):
145
146			@{ defined $var->[0] ? $var->[0] : [] }
147
148			... which nobody with a bit of common sense would consider
149			writing: clear code is clearly something else.
150
151			Curiously enough, sometimes perl is not so strict, as this works even with
152			C<use strict> in scope:
153
154			for (@{ $var->[0] }) { ...
155
156			If that isn't hypocrisy! And all that from a mere program!
157
158
159			=item use feature qw(say state given)
160
161			We found it annoying that we always have to enable extra features. If
162			something breaks because it didn't anticipate future changes, so be
163			it. 5.10 broke almost all our XS modules and nobody cared either (or at
164			least I know of nobody who really complained about gratuitous changes -
165			as opposed to bugs).
166
167			Few modules that are not actively maintained work with newer versions of
168			Perl, regardless of use feature or not, so a new major perl release means
169			changes to many modules - new keywords are just the tip of the iceberg.
170
171			If your code isn't alive, it's dead, Jim - be an active maintainer.
172
173			But nobody forces you to use those extra features in modules meant for
174			older versions of perl - common::sense of course works there as well.
175			There is also an important other mode where having additional features by
176			default is useful: commandline hacks and internal use scripts: See "much
177			reduced typing", below.
178
179
180			=item no warnings, but a lot of new errors
181
182			Ah, the dreaded warnings. Even worse, the horribly dreaded C<-w>
183			switch: Even though we don't care if other people use warnings (and
184			certainly there are useful ones), a lot of warnings simply go against the
185			spirit of Perl.
186
187			Most prominently, the warnings related to C<undef>. There is nothing wrong
188			with C<undef>: it has well-defined semantics, it is useful, and spitting
189			out warnings you never asked for is just evil.
190
191			The result was that every one of our modules did C<no warnings> in the
192			past, to avoid somebody accidentally using and forcing his bad standards
193			on our code. Of course, this switched off all warnings, even the useful
194			ones. Not a good situation. Really, the C<-w> switch should only enable
195			warnings for the main program only.
196
197			Funnily enough, L<perllexwarn> explicitly mentions C<-w> (and not in a
198			favourable way, calling it outright "wrong"), but standard utilities, such
199			as L<prove>, or MakeMaker when running C<make test>, still enable them
200			blindly.
201
202			For version 2 of common::sense, we finally sat down a few hours and went
203			through I<every single warning message>, identifiying - according to
204			common sense - all the useful ones.
205
206			This resulted in the rather impressive list in the SYNOPSIS. When we
207			weren't sure, we didn't include the warning, so the list might grow in
208			the future (we might have made a mistake, too, so the list might shrink
209			as well).
210
211			Note the presence of C<FATAL> in the list: we do not think that the
212			conditions caught by these warnings are worthy of a warning, we I<insist>
213			that they are worthy of I<stopping> your program, I<instantly>. They are
214			I<bugs>!
215
216			Therefore we consider C<common::sense> to be much stricter than C<use
217			warnings>, which is good if you are into strict things (we are not,
218			actually, but these things tend to be subjective).
219
220			After deciding on the list, we ran the module against all of our code that
221			uses C<common::sense> (that is almost all of our code), and found only one
222			occurence where one of them caused a problem: one of elmex's (unreleased)
223			modules contained:
224
225			$fmt =~ s/([^\s\[])\[( [^\]] )\]/\x0$1\x1$2\x0/xgo;
226
227			We quickly agreed that indeed the code should be changed, even though it
228			happened to do the right thing when the warning was switched off.
229
230
231			=item much reduced typing
232
233			Especially with version 2.0 of common::sense, the amount of boilerplate
234			code you need to add to gte I<this> policy is daunting. Nobody would write
235			this out in throwaway scripts, commandline hacks or in quick internal-use
236			scripts.
237
238			By using common::sense you get a defined set of policies (ours, but maybe
239			yours, too, if you accept them), and they are easy to apply to your
240			scripts: typing C<use common::sense;> is even shorter than C<use warnings;
241			use strict; use feature ...>.
242
243			And you can immediately use the features of your installed perl, which
244			is more difficult in code you release, but not usually an issue for
245			internal-use code (downgrades of your production perl should be rare,
246			right?).
247
248
249			=item mucho reduced memory usage
250
251			Just using all those pragmas mentioned in the SYNOPSIS together wastes
252			<blink>I<< B<776> kilobytes >></blink> of precious memory in my perl, for
253			I<every single perl process using our code>, which on our machines, is a
254			lot. In comparison, this module only uses I<< B<four> >> kilobytes (I even
255			had to write it out so it looks like more) of memory on the same platform.
256
257			The money/time/effort/electricity invested in these gigabytes (probably
258			petabytes globally!) of wasted memory could easily save 42 trees, and a
259			kitten!
260
261			Unfortunately, until everybods applies more common sense, there will still
262			often be modules that pull in the monster pragmas. But one can hope...
263
264			=cut
265
266			package common::sense;
267
268	root	1.6	our $VERSION = '3.3';
269	root	1.1
270			# overload should be included
271
272			sub import {
273			IMPORT
274			# use feature
275			$^H{feature_switch} =
276			$^H{feature_say} =
277			$^H{feature_state} = 1;
278			}
279
280			1;
281
282			=back
283
284			=head1 THERE IS NO 'no common::sense'!!!! !!!! !!
285
286			This module doesn't offer an unimport. First of all, it wastes even more
287			memory, second, and more importantly, who with even a bit of common sense
288			would want no common sense?
289
290			=head1 STABILITY AND FUTURE VERSIONS
291
292			Future versions might change just about everything in this module. We
293			might test our modules and upload new ones working with newer versions of
294			this module, and leave you standing in the rain because we didn't tell
295			you. In fact, we did so when switching from 1.0 to 2.0, which enabled gobs
296			of warnings, and made them FATAL on top.
297
298			Maybe we will load some nifty modules that try to emulate C<say> or so
299			with perls older than 5.10 (this module, of course, should work with older
300			perl versions - supporting 5.8 for example is just common sense at this
301			time. Maybe not in the future, but of course you can trust our common
302			sense to be consistent with, uhm, our opinion).
303
304			=head1 WHAT OTHER PEOPLE HAD TO SAY ABOUT THIS MODULE
305
306			apeiron
307
308			"... wow"
309			"I hope common::sense is a joke."
310
311			crab
312
313			"i wonder how it would be if joerg schilling wrote perl modules."
314
315			Adam Kennedy
316
317			"Very interesting, efficient, and potentially something I'd use all the time."
318			[...]
319			"So no common::sense for me, alas."
320
321			H.Merijn Brand
322
323			"Just one more reason to drop JSON::XS from my distribution list"
324
325			Pista Palo
326
327			"Something in short supply these days..."
328
329			Steffen Schwigon
330
331			"This module is quite for sure not just a repetition of all the other
332			'use strict, use warnings'-approaches, and it's also not the opposite.
333			[...] And for its chosen middle-way it's also not the worst name ever.
334			And everything is documented."
335
336			BKB
337
338			"[Deleted - thanks to Steffen Schwigon for pointing out this review was
339			in error.]"
340
341			Somni
342
343			"the arrogance of the guy"
344			"I swear he tacked somenoe else's name onto the module
345			just so he could use the royal 'we' in the documentation"
346
347			Anonymous Monk
348
349			"You just gotta love this thing, its got META.json!!!"
350
351			dngor
352
353			"Heh. '"<elmex at ta-sa.org>"' The quotes are semantic
354			distancing from that e-mail address."
355
356			Jerad Pierce
357
358			"Awful name (not a proper pragma), and the SYNOPSIS doesn't tell you
359			anything either. Nor is it clear what features have to do with "common
360			sense" or discipline."
361
362			acme
363
364			"THERE IS NO 'no common::sense'!!!! !!!! !!"
365
366			apeiron (meta-comment about us commenting^Wquoting his comment)
367
368			"How about quoting this: get a clue, you fucktarded amoeba."
369
370			quanth
371
372			"common sense is beautiful, json::xs is fast, Anyevent, EV are fast and
373			furious. I love mlehmannware ;)"
374
375			apeiron
376
377			"... it's mlehmann's view of what common sense is. His view of common
378			sense is certainly uncommon, insofar as anyone with a clue disagrees
379			with him."
380
381			apeiron (another meta-comment)
382
383			"apeiron wonders if his little informant is here to steal more quotes"
384
385			ew73
386
387			"... I never got past the SYNOPSIS before calling it shit."
388			[...]
389			How come no one ever quotes me. :("
390
391			=head1 FREQUENTLY ASKED QUESTIONS
392
393			Or frequently-come-up confusions.
394
395			=over 4
396
397			=item Is this module meant to be serious?
398
399			Yes, we would have put it under the C<Acme::> namespace otherwise.
400
401			=item But the manpage is written in a funny/stupid/... way?
402
403			This was meant to make it clear that our common sense is a subjective
404			thing and other people can use their own notions, taking the steam out
405			of anybody who might be offended (as some people are always offended no
406			matter what you do).
407
408			This was a failure.
409
410			But we hope the manpage still is somewhat entertaining even though it
411			explains boring rationale.
412
413			=item Why do you impose your conventions on my code?
414
415			For some reason people keep thinking that C<common::sense> imposes
416			process-wide limits, even though the SYNOPSIS makes it clear that it works
417			like other similar modules - i.e. only within the scope that C<use>s them.
418
419			So, no, we don't - nobody is forced to use this module, and using a module
420			that relies on common::sense does not impose anything on you.
421
422			=item Why do you think only your notion of common::sense is valid?
423
424			Well, we don't, and have clearly written this in the documentation to
425			every single release. We were just faster than anybody else w.r.t. to
426			grabbing the namespace.
427
428			=item But everybody knows that you have to use strict and use warnings,
429			why do you disable them?
430
431			Well, we don't do this either - we selectively disagree with the
432			usefulness of some warnings over others. This module is aimed at
433			experienced Perl programmers, not people migrating from other languages
434			who might be surprised about stuff such as C<undef>. On the other hand,
435			this does not exclude the usefulness of this module for total newbies, due
436			to its strictness in enforcing policy, while at the same time not limiting
437			the expresive power of perl.
438
439			This module is considerably I<more> strict than the canonical C<use
440			strict; use warnings>, as it makes all its warnings fatal in nature, so
441			you can not get away with as many things as with the canonical approach.
442
443			This was not implemented in version 1.0 because of the daunting number
444			of warning categories and the difficulty in getting exactly the set of
445			warnings you wish (i.e. look at the SYNOPSIS in how complicated it is to
446			get a specific set of warnings - it is not reasonable to put this into
447	root	1.3	every module, the maintenance effort would be enourmous).
448	root	1.1
449			=item But many modules C<use strict> or C<use warnings>, so the memory
450			savings do not apply?
451
452			I suddenly feel sad...
453
454			But yes, that's true. Fortunately C<common::sense> still uses only a
455			miniscule amount of RAM.
456
457			=item But it adds another dependency to your modules!
458
459			It's a fact, yeah. But it's trivial to install, most popular modules have
460			many more dependencies and we consider dependencies a good thing - it
461			leads to better APIs, more thought about interworking of modules and so
462			on.
463
464			=item Why do you use JSON and not YAML for your META.yml?
465
466			This is not true - YAML supports a large subset of JSON, and this subset
467			is what META.yml is written in, so it would be correct to say "the
468			META.yml is written in a common subset of YAML and JSON".
469
470			The META.yml follows the YAML, JSON and META.yml specifications, and is
471			correctly parsed by CPAN, so if you have trouble with it, the problem is
472			likely on your side.
473
474			=item But! But!
475
476			Yeah, we know.
477
478			=back
479
480			=head1 AUTHOR
481
482			Marc Lehmann <schmorp@schmorp.de>
483			http://home.schmorp.de/
484
485			Robin Redeker, "<elmex at ta-sa.org>".
486
487			=cut
488