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 exiting 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 exiting glob digit printf layer
 #                 reserved taint closure semicolon);
 # no warnings qw(exec newline unopened);

=head1 DESCRIPTION

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 = '3.2';

# 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:	1.4
Committed:	Thu Apr 15 23:46:22 2010 UTC (14 years, 2 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-3_2
Changes since 1.3:	+3 -3 lines
Log Message:	3.2
#	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	1.1	inplace io pipe unpack regexp deprecated exiting 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			# deprecated exiting glob digit printf layer
62	root	1.2	# reserved taint closure semicolon);
63	root	1.1	# no warnings qw(exec newline unopened);
64
65			=head1 DESCRIPTION
66
67			This module implements some sane defaults for Perl programs, as defined by
68			two typical (or not so typical - use your common sense) specimens of Perl
69			coders. In fact, after working out details on which warnings and strict
70			modes to enable and make fatal, we found that we (and our code written so
71			far, and others) fully agree on every option, even though we never used
72			warnings before, so it seems this module indeed reflects a "common" sense
73			among some long-time Perl coders.
74
75			The basic philosophy behind the choices made in common::sense can be
76			summarised as: "enforcing strict policies to catch as many bugs as
77			possible, while at the same time, not limiting the expressive power
78			available to the programmer".
79
80			Two typical examples of how this philosophy is applied in practise is the
81			handling of uninitialised and malloc warnings:
82
83			=over 4
84
85			=item I<uninitialised>
86
87			C<undef> is a well-defined feature of perl, and enabling warnings for
88			using it rarely catches any bugs, but considerably limits you in what you
89			can do, so uninitialised warnings are disabled.
90
91			=item I<malloc>
92
93			Freeing something twice on the C level is a serious bug, usually causing
94			memory corruption. It often leads to side effects much later in the
95			program and there are no advantages to not reporting this, so malloc
96			warnings are fatal by default.
97
98			=back
99
100			What follows is a more thorough discussion of what this module does,
101			and why it does it, and what the advantages (and disadvantages) of this
102			approach are.
103
104			=head1 RATIONALE
105
106			=over 4
107
108			=item use utf8
109
110			While it's not common sense to write your programs in UTF-8, it's quickly
111			becoming the most common encoding, is the designated future default
112			encoding for perl sources, and the most convenient encoding available
113			(you can do really nice quoting tricks...). Experience has shown that our
114			programs were either all pure ascii or utf-8, both of which will stay the
115			same.
116
117			There are few drawbacks to enabling UTF-8 source code by default (mainly
118			some speed hits due to bugs in older versions of perl), so this module
119			enables UTF-8 source code encoding by default.
120
121
122			=item use strict qw(subs vars)
123
124			Using C<use strict> is definitely common sense, but C<use strict
125			'refs'> definitely overshoots its usefulness. After almost two
126			decades of Perl hacking, we decided that it does more harm than being
127			useful. Specifically, constructs like these:
128
129			@{ $var->[0] }
130
131			Must be written like this (or similarly), when C<use strict 'refs'> is in
132			scope, and C<$var> can legally be C<undef>:
133
134			@{ $var->[0] \|\| [] }
135
136			This is annoying, and doesn't shield against obvious mistakes such as
137			using C<"">, so one would even have to write (at least for the time
138			being):
139
140			@{ defined $var->[0] ? $var->[0] : [] }
141
142			... which nobody with a bit of common sense would consider
143			writing: clear code is clearly something else.
144
145			Curiously enough, sometimes perl is not so strict, as this works even with
146			C<use strict> in scope:
147
148			for (@{ $var->[0] }) { ...
149
150			If that isn't hypocrisy! And all that from a mere program!
151
152
153			=item use feature qw(say state given)
154
155			We found it annoying that we always have to enable extra features. If
156			something breaks because it didn't anticipate future changes, so be
157			it. 5.10 broke almost all our XS modules and nobody cared either (or at
158			least I know of nobody who really complained about gratuitous changes -
159			as opposed to bugs).
160
161			Few modules that are not actively maintained work with newer versions of
162			Perl, regardless of use feature or not, so a new major perl release means
163			changes to many modules - new keywords are just the tip of the iceberg.
164
165			If your code isn't alive, it's dead, Jim - be an active maintainer.
166
167			But nobody forces you to use those extra features in modules meant for
168			older versions of perl - common::sense of course works there as well.
169			There is also an important other mode where having additional features by
170			default is useful: commandline hacks and internal use scripts: See "much
171			reduced typing", below.
172
173
174			=item no warnings, but a lot of new errors
175
176			Ah, the dreaded warnings. Even worse, the horribly dreaded C<-w>
177			switch: Even though we don't care if other people use warnings (and
178			certainly there are useful ones), a lot of warnings simply go against the
179			spirit of Perl.
180
181			Most prominently, the warnings related to C<undef>. There is nothing wrong
182			with C<undef>: it has well-defined semantics, it is useful, and spitting
183			out warnings you never asked for is just evil.
184
185			The result was that every one of our modules did C<no warnings> in the
186			past, to avoid somebody accidentally using and forcing his bad standards
187			on our code. Of course, this switched off all warnings, even the useful
188			ones. Not a good situation. Really, the C<-w> switch should only enable
189			warnings for the main program only.
190
191			Funnily enough, L<perllexwarn> explicitly mentions C<-w> (and not in a
192			favourable way, calling it outright "wrong"), but standard utilities, such
193			as L<prove>, or MakeMaker when running C<make test>, still enable them
194			blindly.
195
196			For version 2 of common::sense, we finally sat down a few hours and went
197			through I<every single warning message>, identifiying - according to
198			common sense - all the useful ones.
199
200			This resulted in the rather impressive list in the SYNOPSIS. When we
201			weren't sure, we didn't include the warning, so the list might grow in
202			the future (we might have made a mistake, too, so the list might shrink
203			as well).
204
205			Note the presence of C<FATAL> in the list: we do not think that the
206			conditions caught by these warnings are worthy of a warning, we I<insist>
207			that they are worthy of I<stopping> your program, I<instantly>. They are
208			I<bugs>!
209
210			Therefore we consider C<common::sense> to be much stricter than C<use
211			warnings>, which is good if you are into strict things (we are not,
212			actually, but these things tend to be subjective).
213
214			After deciding on the list, we ran the module against all of our code that
215			uses C<common::sense> (that is almost all of our code), and found only one
216			occurence where one of them caused a problem: one of elmex's (unreleased)
217			modules contained:
218
219			$fmt =~ s/([^\s\[])\[( [^\]] )\]/\x0$1\x1$2\x0/xgo;
220
221			We quickly agreed that indeed the code should be changed, even though it
222			happened to do the right thing when the warning was switched off.
223
224
225			=item much reduced typing
226
227			Especially with version 2.0 of common::sense, the amount of boilerplate
228			code you need to add to gte I<this> policy is daunting. Nobody would write
229			this out in throwaway scripts, commandline hacks or in quick internal-use
230			scripts.
231
232			By using common::sense you get a defined set of policies (ours, but maybe
233			yours, too, if you accept them), and they are easy to apply to your
234			scripts: typing C<use common::sense;> is even shorter than C<use warnings;
235			use strict; use feature ...>.
236
237			And you can immediately use the features of your installed perl, which
238			is more difficult in code you release, but not usually an issue for
239			internal-use code (downgrades of your production perl should be rare,
240			right?).
241
242
243			=item mucho reduced memory usage
244
245			Just using all those pragmas mentioned in the SYNOPSIS together wastes
246			<blink>I<< B<776> kilobytes >></blink> of precious memory in my perl, for
247			I<every single perl process using our code>, which on our machines, is a
248			lot. In comparison, this module only uses I<< B<four> >> kilobytes (I even
249			had to write it out so it looks like more) of memory on the same platform.
250
251			The money/time/effort/electricity invested in these gigabytes (probably
252			petabytes globally!) of wasted memory could easily save 42 trees, and a
253			kitten!
254
255			Unfortunately, until everybods applies more common sense, there will still
256			often be modules that pull in the monster pragmas. But one can hope...
257
258			=cut
259
260			package common::sense;
261
262	root	1.4	our $VERSION = '3.2';
263	root	1.1
264			# overload should be included
265
266			sub import {
267			IMPORT
268			# use feature
269			$^H{feature_switch} =
270			$^H{feature_say} =
271			$^H{feature_state} = 1;
272			}
273
274			1;
275
276			=back
277
278			=head1 THERE IS NO 'no common::sense'!!!! !!!! !!
279
280			This module doesn't offer an unimport. First of all, it wastes even more
281			memory, second, and more importantly, who with even a bit of common sense
282			would want no common sense?
283
284			=head1 STABILITY AND FUTURE VERSIONS
285
286			Future versions might change just about everything in this module. We
287			might test our modules and upload new ones working with newer versions of
288			this module, and leave you standing in the rain because we didn't tell
289			you. In fact, we did so when switching from 1.0 to 2.0, which enabled gobs
290			of warnings, and made them FATAL on top.
291
292			Maybe we will load some nifty modules that try to emulate C<say> or so
293			with perls older than 5.10 (this module, of course, should work with older
294			perl versions - supporting 5.8 for example is just common sense at this
295			time. Maybe not in the future, but of course you can trust our common
296			sense to be consistent with, uhm, our opinion).
297
298			=head1 WHAT OTHER PEOPLE HAD TO SAY ABOUT THIS MODULE
299
300			apeiron
301
302			"... wow"
303			"I hope common::sense is a joke."
304
305			crab
306
307			"i wonder how it would be if joerg schilling wrote perl modules."
308
309			Adam Kennedy
310
311			"Very interesting, efficient, and potentially something I'd use all the time."
312			[...]
313			"So no common::sense for me, alas."
314
315			H.Merijn Brand
316
317			"Just one more reason to drop JSON::XS from my distribution list"
318
319			Pista Palo
320
321			"Something in short supply these days..."
322
323			Steffen Schwigon
324
325			"This module is quite for sure not just a repetition of all the other
326			'use strict, use warnings'-approaches, and it's also not the opposite.
327			[...] And for its chosen middle-way it's also not the worst name ever.
328			And everything is documented."
329
330			BKB
331
332			"[Deleted - thanks to Steffen Schwigon for pointing out this review was
333			in error.]"
334
335			Somni
336
337			"the arrogance of the guy"
338			"I swear he tacked somenoe else's name onto the module
339			just so he could use the royal 'we' in the documentation"
340
341			Anonymous Monk
342
343			"You just gotta love this thing, its got META.json!!!"
344
345			dngor
346
347			"Heh. '"<elmex at ta-sa.org>"' The quotes are semantic
348			distancing from that e-mail address."
349
350			Jerad Pierce
351
352			"Awful name (not a proper pragma), and the SYNOPSIS doesn't tell you
353			anything either. Nor is it clear what features have to do with "common
354			sense" or discipline."
355
356			acme
357
358			"THERE IS NO 'no common::sense'!!!! !!!! !!"
359
360			apeiron (meta-comment about us commenting^Wquoting his comment)
361
362			"How about quoting this: get a clue, you fucktarded amoeba."
363
364			quanth
365
366			"common sense is beautiful, json::xs is fast, Anyevent, EV are fast and
367			furious. I love mlehmannware ;)"
368
369			apeiron
370
371			"... it's mlehmann's view of what common sense is. His view of common
372			sense is certainly uncommon, insofar as anyone with a clue disagrees
373			with him."
374
375			apeiron (another meta-comment)
376
377			"apeiron wonders if his little informant is here to steal more quotes"
378
379			ew73
380
381			"... I never got past the SYNOPSIS before calling it shit."
382			[...]
383			How come no one ever quotes me. :("
384
385			=head1 FREQUENTLY ASKED QUESTIONS
386
387			Or frequently-come-up confusions.
388
389			=over 4
390
391			=item Is this module meant to be serious?
392
393			Yes, we would have put it under the C<Acme::> namespace otherwise.
394
395			=item But the manpage is written in a funny/stupid/... way?
396
397			This was meant to make it clear that our common sense is a subjective
398			thing and other people can use their own notions, taking the steam out
399			of anybody who might be offended (as some people are always offended no
400			matter what you do).
401
402			This was a failure.
403
404			But we hope the manpage still is somewhat entertaining even though it
405			explains boring rationale.
406
407			=item Why do you impose your conventions on my code?
408
409			For some reason people keep thinking that C<common::sense> imposes
410			process-wide limits, even though the SYNOPSIS makes it clear that it works
411			like other similar modules - i.e. only within the scope that C<use>s them.
412
413			So, no, we don't - nobody is forced to use this module, and using a module
414			that relies on common::sense does not impose anything on you.
415
416			=item Why do you think only your notion of common::sense is valid?
417
418			Well, we don't, and have clearly written this in the documentation to
419			every single release. We were just faster than anybody else w.r.t. to
420			grabbing the namespace.
421
422			=item But everybody knows that you have to use strict and use warnings,
423			why do you disable them?
424
425			Well, we don't do this either - we selectively disagree with the
426			usefulness of some warnings over others. This module is aimed at
427			experienced Perl programmers, not people migrating from other languages
428			who might be surprised about stuff such as C<undef>. On the other hand,
429			this does not exclude the usefulness of this module for total newbies, due
430			to its strictness in enforcing policy, while at the same time not limiting
431			the expresive power of perl.
432
433			This module is considerably I<more> strict than the canonical C<use
434			strict; use warnings>, as it makes all its warnings fatal in nature, so
435			you can not get away with as many things as with the canonical approach.
436
437			This was not implemented in version 1.0 because of the daunting number
438			of warning categories and the difficulty in getting exactly the set of
439			warnings you wish (i.e. look at the SYNOPSIS in how complicated it is to
440			get a specific set of warnings - it is not reasonable to put this into
441	root	1.3	every module, the maintenance effort would be enourmous).
442	root	1.1
443			=item But many modules C<use strict> or C<use warnings>, so the memory
444			savings do not apply?
445
446			I suddenly feel sad...
447
448			But yes, that's true. Fortunately C<common::sense> still uses only a
449			miniscule amount of RAM.
450
451			=item But it adds another dependency to your modules!
452
453			It's a fact, yeah. But it's trivial to install, most popular modules have
454			many more dependencies and we consider dependencies a good thing - it
455			leads to better APIs, more thought about interworking of modules and so
456			on.
457
458			=item Why do you use JSON and not YAML for your META.yml?
459
460			This is not true - YAML supports a large subset of JSON, and this subset
461			is what META.yml is written in, so it would be correct to say "the
462			META.yml is written in a common subset of YAML and JSON".
463
464			The META.yml follows the YAML, JSON and META.yml specifications, and is
465			correctly parsed by CPAN, so if you have trouble with it, the problem is
466			likely on your side.
467
468			=item But! But!
469
470			Yeah, we know.
471
472			=back
473
474			=head1 AUTHOR
475
476			Marc Lehmann <schmorp@schmorp.de>
477			http://home.schmorp.de/
478
479			Robin Redeker, "<elmex at ta-sa.org>".
480
481			=cut
482