cvsroot/common-sense/sense.pm

=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 substr malloc
 #                 portable prototype inplace io pipe unpack regexp
 #                 deprecated exiting glob digit printf layer
 #                 reserved parenthesis 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 this philosophy are uninitialised and malloc
warnings:

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.

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.

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.

=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, 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 = '3.0';

# paste this into perl to find bitmask

# no warnings;
# use warnings qw(FATAL closed threads internal debugging pack substr malloc portable prototype
#                 inplace io pipe unpack regexp deprecated exiting glob digit printf
#                 layer reserved parenthesis taint closure semicolon);
# no warnings qw(exec newline unopened);
# BEGIN { warn join "", map "\\x$_", unpack "(H2)*", ${^WARNING_BITS}; exit 0 };

# overload should be included

sub import {
   # verified with perl 5.8.0, 5.10.0
   ${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";

   # use utf8, strict vars subs
   $^H |= 0x00800600;

   # 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 ;)"

=head1 FREQUQNTLY 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 - only on the scope that uses 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 maintainance effort would be enourmous).

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

I am suddenly so 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:	1.25
Committed:	Tue Dec 15 02:25:31 2009 UTC (16 years, 9 months ago) by root
Branch:	MAIN
CVS Tags:	rel-3_0
Changes since 1.24:	+19 -6 lines
Log Message:	3.0
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3			common::sense - save a tree AND a kitten, use common::sense!
4
5			=head1 SYNOPSIS
6
7			use common::sense;
8
9	root	1.19	# supposed to be the same, with much lower memory usage, as:
10	root	1.1	#
11	root	1.25	# use utf8;
12	root	1.1	# use strict qw(vars subs);
13			# use feature qw(say state switch);
14			# no warnings;
15	root	1.15	# use warnings qw(FATAL closed threads internal debugging pack substr malloc
16	root	1.24	# portable prototype inplace io pipe unpack regexp
17	root	1.25	# deprecated exiting glob digit printf layer
18	root	1.15	# reserved parenthesis taint closure semicolon);
19	root	1.24	# no warnings qw(exec newline unopened);
20	root	1.1
21			=head1 DESCRIPTION
22
23			This module implements some sane defaults for Perl programs, as defined by
24	root	1.16	two typical (or not so typical - use your common sense) specimens of Perl
25	root	1.21	coders. In fact, after working out details on which warnings and strict
26			modes to enable and make fatal, we found that we (and our code written so
27			far, and others) fully agree on every option, even though we never used
28			warnings before, so it seems this module indeed reflects a "common" sense
29			among some long-time Perl coders.
30	root	1.1
31	root	1.22	The basic philosophy behind the choices made in common::sense can be
32			summarised as: "enforcing strict policies to catch as many bugs as
33			possible, while at the same time, not limiting the expressive power
34			available to the programmer".
35
36			Two typical examples of this philosophy are uninitialised and malloc
37			warnings:
38
39			C<undef> is a well-defined feature of perl, and enabling warnings for
40			using it rarely catches any bugs, but considerably limits you in what you
41			can do, so uninitialised warnings are disabled.
42
43			Freeing something twice on the C level is a serious bug, usually causing
44			memory corruption. It often leads to side effects much later in the
45			program and there are no advantages to not reporting this, so malloc
46			warnings are fatal by default.
47
48			What follows is a more thorough discussion of what this module does,
49			and why it does it, and what the advantages (and disadvantages) of this
50			approach are.
51
52	root	1.1	=over 4
53
54	root	1.25	=item use utf8
55
56			While it's not common sense to write your programs in UTF-8, it's quickly
57			becoming the most common encoding, and the most convenient encoding
58			available (you can do really nice quoting tricks...). Experience has shown
59			that our programs were either all pure ascii or utf-8, both of which will
60			stay the same.
61
62			There are few drawbacks to enabling UTF-8 source code by default (mainly
63			some speed hits due to bugs in older versions of perl), so this module
64			enables UTF-8 source code encoding by default.
65
66	root	1.1	=item use strict qw(subs vars)
67
68			Using C<use strict> is definitely common sense, but C<use strict
69	root	1.11	'refs'> definitely overshoots its usefulness. After almost two
70	root	1.1	decades of Perl hacking, we decided that it does more harm than being
71			useful. Specifically, constructs like these:
72
73			@{ $var->[0] }
74
75	root	1.4	Must be written like this (or similarly), when C<use strict 'refs'> is in
76			scope, and C<$var> can legally be C<undef>:
77	root	1.1
78			@{ $var->[0] \|\| [] }
79
80			This is annoying, and doesn't shield against obvious mistakes such as
81	root	1.11	using C<"">, so one would even have to write (at least for the time
82			being):
83	root	1.1
84	root	1.18	@{ defined $var->[0] ? $var->[0] : [] }
85	root	1.1
86			... which nobody with a bit of common sense would consider
87	root	1.18	writing: clear code is clearly something else.
88	root	1.11
89			Curiously enough, sometimes perl is not so strict, as this works even with
90			C<use strict> in scope:
91	root	1.1
92			for (@{ $var->[0] }) { ...
93
94	root	1.15	If that isn't hypocrisy! And all that from a mere program!
95
96	root	1.1
97			=item use feature qw(say state given)
98
99			We found it annoying that we always have to enable extra features. If
100			something breaks because it didn't anticipate future changes, so be
101	root	1.11	it. 5.10 broke almost all our XS modules and nobody cared either (or at
102	root	1.15	least I know of nobody who really complained about gratuitous changes -
103			as opposed to bugs).
104	root	1.11
105			Few modules that are not actively maintained work with newer versions of
106			Perl, regardless of use feature or not, so a new major perl release means
107			changes to many modules - new keywords are just the tip of the iceberg.
108
109	root	1.15	If your code isn't alive, it's dead, Jim - be an active maintainer.
110
111	root	1.22	But nobody forces you to use those extra features in modules meant for
112			older versions of perl - common::sense of course works there as well.
113			There is also an important other mode where having additional features by
114			default is useful: commandline hacks and internal use scripts: See "much
115			reduced typing", below.
116
117	root	1.15
118	root	1.16	=item no warnings, but a lot of new errors
119	root	1.15
120			Ah, the dreaded warnings. Even worse, the horribly dreaded C<-w>
121			switch: Even though we don't care if other people use warnings (and
122			certainly there are useful ones), a lot of warnings simply go against the
123			spirit of Perl.
124
125			Most prominently, the warnings related to C<undef>. There is nothing wrong
126			with C<undef>: it has well-defined semantics, it is useful, and spitting
127			out warnings you never asked for is just evil.
128
129	root	1.16	The result was that every one of our modules did C<no warnings> in the
130			past, to avoid somebody accidentally using and forcing his bad standards
131			on our code. Of course, this switched off all warnings, even the useful
132			ones. Not a good situation. Really, the C<-w> switch should only enable
133			warnings for the main program only.
134	root	1.15
135			Funnily enough, L<perllexwarn> explicitly mentions C<-w> (and not in a
136			favourable way, calling it outright "wrong"), but standard utilities, such
137			as L<prove>, or MakeMaker when running C<make test>, still enable them
138			blindly.
139
140	root	1.16	For version 2 of common::sense, we finally sat down a few hours and went
141			through I<every single warning message>, identifiying - according to
142			common sense - all the useful ones.
143	root	1.15
144			This resulted in the rather impressive list in the SYNOPSIS. When we
145			weren't sure, we didn't include the warning, so the list might grow in
146			the future (we might have made a mistake, too, so the list might shrink
147	root	1.16	as well).
148	root	1.15
149			Note the presence of C<FATAL> in the list: we do not think that the
150			conditions caught by these warnings are worthy of a warning, we I<insist>
151	root	1.16	that they are worthy of I<stopping> your program, I<instantly>. They are
152			I<bugs>!
153	root	1.15
154			Therefore we consider C<common::sense> to be much stricter than C<use
155			warnings>, which is good if you are into strict things (we are not,
156			actually, but these things tend to be subjective).
157
158			After deciding on the list, we ran the module against all of our code that
159			uses C<common::sense> (that is almost all of our code), and found only one
160			occurence where one of them caused a problem: one of elmex's (unreleased)
161			modules contained:
162
163			$fmt =~ s/([^\s\[])\[( [^\]] )\]/\x0$1\x1$2\x0/xgo;
164
165			We quickly agreed that indeed the code should be changed, even though it
166			happened to do the right thing when the warning was switched off.
167
168	root	1.11
169	root	1.22	=item much reduced typing
170
171			Especially with version 2.0 of common::sense, the amount of boilerplate
172			code you need to add to gte I<this> policy is daunting. Nobody would write
173			this out in throwaway scripts, commandline hacks or in quick internal-use
174			scripts.
175
176			By using common::sense you get a defined set of policies (ours, but maybe
177			yours, too, if you accept them), and they are easy to apply to your
178			scripts: typing C<use common::sense;> is even shorter than C<use warnings;
179			use strict; use feature ...>.
180
181			And you can immediately use the features of your installed perl, which
182			is more difficult in code you release, but not usually an issue for
183			internal-use code (downgrades of your production perl should be rare,
184			right?).
185
186
187	root	1.11	=item mucho reduced memory usage
188
189			Just using all those pragmas mentioned in the SYNOPSIS together wastes
190			<blink>I<< B<776> kilobytes >></blink> of precious memory in my perl, for
191			I<every single perl process using our code>, which on our machines, is a
192			lot. In comparison, this module only uses I<< B<four> >> kilobytes (I even
193			had to write it out so it looks like more) of memory on the same platform.
194	root	1.1
195			The money/time/effort/electricity invested in these gigabytes (probably
196			petabytes globally!) of wasted memory could easily save 42 trees, and a
197			kitten!
198
199	root	1.11	Unfortunately, until everybods applies more common sense, there will still
200			often be modules that pull in the monster pragmas. But one can hope...
201
202	root	1.1	=cut
203
204	root	1.2	package common::sense;
205	root	1.1
206	root	1.25	our $VERSION = '3.0';
207	root	1.15
208	root	1.19	# paste this into perl to find bitmask
209	root	1.1
210	root	1.13	# no warnings;
211	root	1.24	# use warnings qw(FATAL closed threads internal debugging pack substr malloc portable prototype
212	root	1.16	# inplace io pipe unpack regexp deprecated exiting glob digit printf
213	root	1.25	# layer reserved parenthesis taint closure semicolon);
214	root	1.24	# no warnings qw(exec newline unopened);
215	root	1.14	# BEGIN { warn join "", map "\\x$_", unpack "(H2)*", ${^WARNING_BITS}; exit 0 };
216	root	1.13
217			# overload should be included
218
219	root	1.2	sub import {
220	root	1.13	# verified with perl 5.8.0, 5.10.0
221	root	1.25	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
222	root	1.3
223	root	1.25	# use utf8, strict vars subs
224			$^H \|= 0x00800600;
225	root	1.3
226			# use feature
227			$^H{feature_switch} =
228			$^H{feature_say} =
229			$^H{feature_state} = 1;
230	root	1.1	}
231
232			1;
233
234			=back
235
236	root	1.5	=head1 THERE IS NO 'no common::sense'!!!! !!!! !!
237	root	1.4
238			This module doesn't offer an unimport. First of all, it wastes even more
239			memory, second, and more importantly, who with even a bit of common sense
240			would want no common sense?
241
242	root	1.5	=head1 STABILITY AND FUTURE VERSIONS
243
244			Future versions might change just about everything in this module. We
245			might test our modules and upload new ones working with newer versions of
246			this module, and leave you standing in the rain because we didn't tell
247	root	1.15	you. In fact, we did so when switching from 1.0 to 2.0, which enabled gobs
248			of warnings, and made them FATAL on top.
249	root	1.5
250	root	1.15	Maybe we will load some nifty modules that try to emulate C<say> or so
251			with perls older than 5.10 (this module, of course, should work with older
252			perl versions - supporting 5.8 for example is just common sense at this
253			time. Maybe not in the future, but of course you can trust our common
254			sense to be consistent with, uhm, our opinion).
255	root	1.11
256			=head1 WHAT OTHER PEOPLE HAD TO SAY ABOUT THIS MODULE
257
258			apeiron
259
260			"... wow"
261			"I hope common::sense is a joke."
262
263			crab
264	root	1.5
265	root	1.11	"i wonder how it would be if joerg schilling wrote perl modules."
266	root	1.7
267	root	1.17	Adam Kennedy
268
269			"Very interesting, efficient, and potentially something I'd use all the time."
270			[...]
271			"So no common::sense for me, alas."
272
273	root	1.11	H.Merijn Brand
274
275			"Just one more reason to drop JSON::XS from my distribution list"
276	root	1.7
277			Pista Palo
278
279			"Something in short supply these days..."
280
281			Steffen Schwigon
282
283			"This module is quite for sure not just a repetition of all the other
284			'use strict, use warnings'-approaches, and it's also not the opposite.
285			[...] And for its chosen middle-way it's also not the worst name ever.
286			And everything is documented."
287
288			BKB
289
290			"[Deleted - thanks to Steffen Schwigon for pointing out this review was
291			in error.]"
292
293			Somni
294
295			"the arrogance of the guy"
296			"I swear he tacked somenoe else's name onto the module
297			just so he could use the royal 'we' in the documentation"
298
299	root	1.23	Anonymous Monk
300
301			"You just gotta love this thing, its got META.json!!!"
302
303	root	1.7	dngor
304
305			"Heh. '"<elmex at ta-sa.org>"' The quotes are semantic
306			distancing from that e-mail address."
307
308			Jerad Pierce
309
310			"Awful name (not a proper pragma), and the SYNOPSIS doesn't tell you
311			anything either. Nor is it clear what features have to do with "common
312			sense" or discipline."
313
314			acme
315
316			"THERE IS NO 'no common::sense'!!!! !!!! !!"
317
318	root	1.15	apeiron (meta-comment about us commenting^Wquoting his comment)
319	root	1.12
320	root	1.23	"How about quoting this: get a clue, you fucktarded amoeba."
321	root	1.12
322	root	1.20	quanth
323
324	root	1.23	"common sense is beautiful, json::xs is fast, Anyevent, EV are fast and
325			furious. I love mlehmannware ;)"
326	root	1.20
327	root	1.19	=head1 FREQUQNTLY ASKED QUESTIONS
328
329			Or frequently-come-up confusions.
330
331			=over 4
332
333			=item Is this module meant to be serious?
334
335			Yes, we would have put it under the C<Acme::> namespace otherwise.
336
337			=item But the manpage is written in a funny/stupid/... way?
338
339			This was meant to make it clear that our common sense is a subjective
340			thing and other people can use their own notions, taking the steam out
341			of anybody who might be offended (as some people are always offended no
342			matter what you do).
343
344			This was a failure.
345
346			But we hope the manpage still is somewhat entertaining even though it
347			explains boring rationale.
348
349			=item Why do you impose your conventions on my code?
350
351			For some reason people keep thinking that C<common::sense> imposes
352			process-wide limits, even though the SYNOPSIS makes it clear that it works
353			like other similar modules - only on the scope that uses them.
354
355			So, no, we don't - nobody is forced to use this module, and using a module
356			that relies on common::sense does not impose anything on you.
357
358			=item Why do you think only your notion of common::sense is valid?
359
360			Well, we don't, and have clearly written this in the documentation to
361			every single release. We were just faster than anybody else w.r.t. to
362			grabbing the namespace.
363
364			=item But everybody knows that you have to use strict and use warnings,
365			why do you disable them?
366
367			Well, we don't do this either - we selectively disagree with the
368			usefulness of some warnings over others. This module is aimed at
369			experienced Perl programmers, not people migrating from other languages
370	root	1.22	who might be surprised about stuff such as C<undef>. On the other hand,
371			this does not exclude the usefulness of this module for total newbies, due
372			to its strictness in enforcing policy, while at the same time not limiting
373			the expresive power of perl.
374
375			This module is considerably I<more> strict than the canonical C<use
376			strict; use warnings>, as it makes all its warnings fatal in nature, so
377			you can not get away with as many things as with the canonical approach.
378	root	1.19
379			This was not implemented in version 1.0 because of the daunting number
380			of warning categories and the difficulty in getting exactly the set of
381			warnings you wish (i.e. look at the SYNOPSIS in how complicated it is to
382			get a specific set of warnings - it is not reasonable to put this into
383			every module, the maintainance effort would be enourmous).
384
385			=item But many modules C<use strict> or C<use warnings>, so the memory
386			savings do not apply?
387
388			I am suddenly so sad.
389
390			But yes, that's true. Fortunately C<common::sense> still uses only a
391			miniscule amount of RAM.
392
393			=item But it adds another dependency to your modules!
394
395			It's a fact, yeah. But it's trivial to install, most popular modules have
396			many more dependencies and we consider dependencies a good thing - it
397			leads to better APIs, more thought about interworking of modules and so
398			on.
399
400	root	1.22	=item Why do you use JSON and not YAML for your META.yml?
401
402			This is not true - YAML supports a large subset of JSON, and this subset
403			is what META.yml is written in, so it would be correct to say "the
404			META.yml is written in a common subset of YAML and JSON".
405
406			The META.yml follows the YAML, JSON and META.yml specifications, and is
407			correctly parsed by CPAN, so if you have trouble with it, the problem is
408			likely on your side.
409
410	root	1.19	=item But! But!
411
412			Yeah, we know.
413
414			=back
415
416	root	1.1	=head1 AUTHOR
417
418			Marc Lehmann <schmorp@schmorp.de>
419			http://home.schmorp.de/
420
421	root	1.4	Robin Redeker, "<elmex at ta-sa.org>".
422
423	root	1.1	=cut
424