common-sense/sense.pod

=head1 NAME

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

=head1 SYNOPSIS

   use common::sense;

   # Supposed to be mostly the same, with much lower memory usage, as:
  
   # use utf8;
   # use strict qw(vars subs);
   # use feature qw(say state switch);
   # use feature qw(unicode_strings unicode_eval current_sub fc evalbytes);
   # no feature qw(array_base);
   # no warnings;
   # use warnings qw(FATAL closed threads internal debugging pack
   #                 prototype inplace io pipe unpack malloc 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

Unfortunately, there is no fine-grained warning control in perl, so often
whole groups of useful warnings had to be excluded because of a single
useless warning (for example, perl puts an arbitrary limit on the length
of text you can match with some regexes before emitting a warning, making
the whole C<regexp> category useless).

What follows is a more thorough discussion of what this module does,
and why it does it, and what the advantages (and disadvantages) of this
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.

There is one notable exception: C<unicode_eval> is not enabled by
default. In our opinion, C<use feature> had one main effect - newer perl
versions don't value backwards compatibility and the ability to write
modules for multiple perl versions much, after all, you can use feature.

C<unicode_eval> doesn't add a new feature, it breaks an existing function.

=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>, identifying - 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
occurrence 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 get 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 everybody applies more common sense, there will still
often be modules that pull in the monster pragmas. But one can hope...

=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. :("

chip (not willing to explain his cryptic questions about links in Changes files)

   "I'm willing to ask the question I've asked. I'm not willing to go
   through the whole dance you apparently have choreographed. Either
   answer the completely obvious question, or tell me to fuck off again."

=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 expressive 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 enormous).

=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:	1.3
Committed:	Thu Apr 2 07:53:41 2020 UTC (4 years, 2 months ago) by root
Branch:	MAIN
CVS Tags:	rel-3_75, HEAD
Changes since 1.2:	+2 -3 lines
Log Message:	3.75
#	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			# Supposed to be mostly the same, with much lower memory usage, as:
10
11			# use utf8;
12			# use strict qw(vars subs);
13			# use feature qw(say state switch);
14			# use feature qw(unicode_strings unicode_eval current_sub fc evalbytes);
15			# no feature qw(array_base);
16			# no warnings;
17			# use warnings qw(FATAL closed threads internal debugging pack
18	root	1.3	# prototype inplace io pipe unpack malloc glob
19			# digit printf layer reserved taint closure semicolon);
20	root	1.1	# no warnings qw(exec newline unopened);
21
22			=head1 DESCRIPTION
23
24			“Nothing is more fairly distributed than common sense: no one thinks
25			he needs more of it than he already has.”
26
27			– René Descartes
28
29			This module implements some sane defaults for Perl programs, as defined by
30			two typical (or not so typical - use your common sense) specimens of Perl
31			coders. In fact, after working out details on which warnings and strict
32			modes to enable and make fatal, we found that we (and our code written so
33			far, and others) fully agree on every option, even though we never used
34			warnings before, so it seems this module indeed reflects a "common" sense
35			among some long-time Perl coders.
36
37			The basic philosophy behind the choices made in common::sense can be
38			summarised as: "enforcing strict policies to catch as many bugs as
39			possible, while at the same time, not limiting the expressive power
40			available to the programmer".
41
42			Two typical examples of how this philosophy is applied in practise is the
43			handling of uninitialised and malloc warnings:
44
45			=over 4
46
47			=item I<uninitialised>
48
49			C<undef> is a well-defined feature of perl, and enabling warnings for
50			using it rarely catches any bugs, but considerably limits you in what you
51			can do, so uninitialised warnings are disabled.
52
53			=item I<malloc>
54
55			Freeing something twice on the C level is a serious bug, usually causing
56			memory corruption. It often leads to side effects much later in the
57			program and there are no advantages to not reporting this, so malloc
58			warnings are fatal by default.
59
60			=back
61
62			Unfortunately, there is no fine-grained warning control in perl, so often
63			whole groups of useful warnings had to be excluded because of a single
64			useless warning (for example, perl puts an arbitrary limit on the length
65			of text you can match with some regexes before emitting a warning, making
66			the whole C<regexp> category useless).
67
68			What follows is a more thorough discussion of what this module does,
69			and why it does it, and what the advantages (and disadvantages) of this
70			approach are.
71
72			=head1 RATIONALE
73
74			=over 4
75
76			=item use utf8
77
78			While it's not common sense to write your programs in UTF-8, it's quickly
79			becoming the most common encoding, is the designated future default
80			encoding for perl sources, and the most convenient encoding available
81			(you can do really nice quoting tricks...). Experience has shown that our
82			programs were either all pure ascii or utf-8, both of which will stay the
83			same.
84
85			There are few drawbacks to enabling UTF-8 source code by default (mainly
86			some speed hits due to bugs in older versions of perl), so this module
87			enables UTF-8 source code encoding by default.
88
89
90			=item use strict qw(subs vars)
91
92			Using C<use strict> is definitely common sense, but C<use strict
93			'refs'> definitely overshoots its usefulness. After almost two
94			decades of Perl hacking, we decided that it does more harm than being
95			useful. Specifically, constructs like these:
96
97			@{ $var->[0] }
98
99			Must be written like this (or similarly), when C<use strict 'refs'> is in
100			scope, and C<$var> can legally be C<undef>:
101
102			@{ $var->[0] \|\| [] }
103
104			This is annoying, and doesn't shield against obvious mistakes such as
105			using C<"">, so one would even have to write (at least for the time
106			being):
107
108			@{ defined $var->[0] ? $var->[0] : [] }
109
110			... which nobody with a bit of common sense would consider
111			writing: clear code is clearly something else.
112
113			Curiously enough, sometimes perl is not so strict, as this works even with
114			C<use strict> in scope:
115
116			for (@{ $var->[0] }) { ...
117
118			If that isn't hypocrisy! And all that from a mere program!
119
120
121			=item use feature qw(say state given ...)
122
123			We found it annoying that we always have to enable extra features. If
124			something breaks because it didn't anticipate future changes, so be
125			it. 5.10 broke almost all our XS modules and nobody cared either (or at
126			least I know of nobody who really complained about gratuitous changes -
127			as opposed to bugs).
128
129			Few modules that are not actively maintained work with newer versions of
130			Perl, regardless of use feature or not, so a new major perl release means
131			changes to many modules - new keywords are just the tip of the iceberg.
132
133			If your code isn't alive, it's dead, Jim - be an active maintainer.
134
135			But nobody forces you to use those extra features in modules meant for
136			older versions of perl - common::sense of course works there as well.
137			There is also an important other mode where having additional features by
138			default is useful: commandline hacks and internal use scripts: See "much
139			reduced typing", below.
140
141			There is one notable exception: C<unicode_eval> is not enabled by
142			default. In our opinion, C<use feature> had one main effect - newer perl
143			versions don't value backwards compatibility and the ability to write
144			modules for multiple perl versions much, after all, you can use feature.
145
146			C<unicode_eval> doesn't add a new feature, it breaks an existing function.
147
148			=item no warnings, but a lot of new errors
149
150			Ah, the dreaded warnings. Even worse, the horribly dreaded C<-w>
151			switch: Even though we don't care if other people use warnings (and
152			certainly there are useful ones), a lot of warnings simply go against the
153			spirit of Perl.
154
155			Most prominently, the warnings related to C<undef>. There is nothing wrong
156			with C<undef>: it has well-defined semantics, it is useful, and spitting
157			out warnings you never asked for is just evil.
158
159			The result was that every one of our modules did C<no warnings> in the
160			past, to avoid somebody accidentally using and forcing his bad standards
161			on our code. Of course, this switched off all warnings, even the useful
162			ones. Not a good situation. Really, the C<-w> switch should only enable
163			warnings for the main program only.
164
165			Funnily enough, L<perllexwarn> explicitly mentions C<-w> (and not in a
166			favourable way, calling it outright "wrong"), but standard utilities, such
167			as L<prove>, or MakeMaker when running C<make test>, still enable them
168			blindly.
169
170			For version 2 of common::sense, we finally sat down a few hours and went
171			through I<every single warning message>, identifying - according to
172			common sense - all the useful ones.
173
174			This resulted in the rather impressive list in the SYNOPSIS. When we
175			weren't sure, we didn't include the warning, so the list might grow in
176			the future (we might have made a mistake, too, so the list might shrink
177			as well).
178
179			Note the presence of C<FATAL> in the list: we do not think that the
180			conditions caught by these warnings are worthy of a warning, we I<insist>
181			that they are worthy of I<stopping> your program, I<instantly>. They are
182			I<bugs>!
183
184			Therefore we consider C<common::sense> to be much stricter than C<use
185			warnings>, which is good if you are into strict things (we are not,
186			actually, but these things tend to be subjective).
187
188			After deciding on the list, we ran the module against all of our code that
189			uses C<common::sense> (that is almost all of our code), and found only one
190			occurrence where one of them caused a problem: one of elmex's (unreleased)
191			modules contained:
192
193			$fmt =~ s/([^\s\[])\[( [^\]] )\]/\x0$1\x1$2\x0/xgo;
194
195			We quickly agreed that indeed the code should be changed, even though it
196			happened to do the right thing when the warning was switched off.
197
198
199			=item much reduced typing
200
201			Especially with version 2.0 of common::sense, the amount of boilerplate
202			code you need to add to get I<this> policy is daunting. Nobody would write
203			this out in throwaway scripts, commandline hacks or in quick internal-use
204			scripts.
205
206			By using common::sense you get a defined set of policies (ours, but maybe
207			yours, too, if you accept them), and they are easy to apply to your
208			scripts: typing C<use common::sense;> is even shorter than C<use warnings;
209			use strict; use feature ...>.
210
211			And you can immediately use the features of your installed perl, which
212			is more difficult in code you release, but not usually an issue for
213			internal-use code (downgrades of your production perl should be rare,
214			right?).
215
216
217			=item mucho reduced memory usage
218
219			Just using all those pragmas mentioned in the SYNOPSIS together wastes
220			<blink>I<< B<776> kilobytes >></blink> of precious memory in my perl, for
221			I<every single perl process using our code>, which on our machines, is a
222			lot. In comparison, this module only uses I<< B<four> >> kilobytes (I even
223			had to write it out so it looks like more) of memory on the same platform.
224
225			The money/time/effort/electricity invested in these gigabytes (probably
226			petabytes globally!) of wasted memory could easily save 42 trees, and a
227			kitten!
228
229			Unfortunately, until everybody applies more common sense, there will still
230			often be modules that pull in the monster pragmas. But one can hope...
231
232			=back
233
234			=head1 THERE IS NO 'no common::sense'!!!! !!!! !!
235
236			This module doesn't offer an unimport. First of all, it wastes even more
237			memory, second, and more importantly, who with even a bit of common sense
238			would want no common sense?
239
240			=head1 STABILITY AND FUTURE VERSIONS
241
242			Future versions might change just about everything in this module. We
243			might test our modules and upload new ones working with newer versions of
244			this module, and leave you standing in the rain because we didn't tell
245			you. In fact, we did so when switching from 1.0 to 2.0, which enabled gobs
246			of warnings, and made them FATAL on top.
247
248			Maybe we will load some nifty modules that try to emulate C<say> or so
249			with perls older than 5.10 (this module, of course, should work with older
250			perl versions - supporting 5.8 for example is just common sense at this
251			time. Maybe not in the future, but of course you can trust our common
252			sense to be consistent with, uhm, our opinion).
253
254			=head1 WHAT OTHER PEOPLE HAD TO SAY ABOUT THIS MODULE
255
256			apeiron
257
258			"... wow"
259			"I hope common::sense is a joke."
260
261			crab
262
263			"i wonder how it would be if joerg schilling wrote perl modules."
264
265			Adam Kennedy
266
267			"Very interesting, efficient, and potentially something I'd use all the time."
268			[...]
269			"So no common::sense for me, alas."
270
271			H.Merijn Brand
272
273			"Just one more reason to drop JSON::XS from my distribution list"
274
275			Pista Palo
276
277			"Something in short supply these days..."
278
279			Steffen Schwigon
280
281			"This module is quite for sure not just a repetition of all the other
282			'use strict, use warnings'-approaches, and it's also not the opposite.
283			[...] And for its chosen middle-way it's also not the worst name ever.
284			And everything is documented."
285
286			BKB
287
288			"[Deleted - thanks to Steffen Schwigon for pointing out this review was
289			in error.]"
290
291			Somni
292
293			"the arrogance of the guy"
294			"I swear he tacked somenoe else's name onto the module
295			just so he could use the royal 'we' in the documentation"
296
297			Anonymous Monk
298
299			"You just gotta love this thing, its got META.json!!!"
300
301			dngor
302
303			"Heh. '"<elmex at ta-sa.org>"' The quotes are semantic
304			distancing from that e-mail address."
305
306			Jerad Pierce
307
308			"Awful name (not a proper pragma), and the SYNOPSIS doesn't tell you
309			anything either. Nor is it clear what features have to do with "common
310			sense" or discipline."
311
312			acme
313
314			"THERE IS NO 'no common::sense'!!!! !!!! !!"
315
316			apeiron (meta-comment about us commenting^Wquoting his comment)
317
318			"How about quoting this: get a clue, you fucktarded amoeba."
319
320			quanth
321
322			"common sense is beautiful, json::xs is fast, Anyevent, EV are fast and
323			furious. I love mlehmannware ;)"
324
325			apeiron
326
327			"... it's mlehmann's view of what common sense is. His view of common
328			sense is certainly uncommon, insofar as anyone with a clue disagrees
329			with him."
330
331			apeiron (another meta-comment)
332
333			"apeiron wonders if his little informant is here to steal more quotes"
334
335			ew73
336
337			"... I never got past the SYNOPSIS before calling it shit."
338			[...]
339			How come no one ever quotes me. :("
340
341			chip (not willing to explain his cryptic questions about links in Changes files)
342
343			"I'm willing to ask the question I've asked. I'm not willing to go
344			through the whole dance you apparently have choreographed. Either
345			answer the completely obvious question, or tell me to fuck off again."
346
347			=head1 FREQUENTLY ASKED QUESTIONS
348
349			Or frequently-come-up confusions.
350
351			=over 4
352
353			=item Is this module meant to be serious?
354
355			Yes, we would have put it under the C<Acme::> namespace otherwise.
356
357			=item But the manpage is written in a funny/stupid/... way?
358
359			This was meant to make it clear that our common sense is a subjective
360			thing and other people can use their own notions, taking the steam out
361			of anybody who might be offended (as some people are always offended no
362			matter what you do).
363
364			This was a failure.
365
366			But we hope the manpage still is somewhat entertaining even though it
367			explains boring rationale.
368
369			=item Why do you impose your conventions on my code?
370
371			For some reason people keep thinking that C<common::sense> imposes
372			process-wide limits, even though the SYNOPSIS makes it clear that it works
373			like other similar modules - i.e. only within the scope that C<use>s them.
374
375			So, no, we don't - nobody is forced to use this module, and using a module
376			that relies on common::sense does not impose anything on you.
377
378			=item Why do you think only your notion of common::sense is valid?
379
380			Well, we don't, and have clearly written this in the documentation to
381			every single release. We were just faster than anybody else w.r.t. to
382			grabbing the namespace.
383
384			=item But everybody knows that you have to use strict and use warnings,
385			why do you disable them?
386
387			Well, we don't do this either - we selectively disagree with the
388			usefulness of some warnings over others. This module is aimed at
389			experienced Perl programmers, not people migrating from other languages
390			who might be surprised about stuff such as C<undef>. On the other hand,
391			this does not exclude the usefulness of this module for total newbies, due
392			to its strictness in enforcing policy, while at the same time not limiting
393			the expressive power of perl.
394
395			This module is considerably I<more> strict than the canonical C<use
396			strict; use warnings>, as it makes all its warnings fatal in nature, so
397			you can not get away with as many things as with the canonical approach.
398
399			This was not implemented in version 1.0 because of the daunting number
400			of warning categories and the difficulty in getting exactly the set of
401			warnings you wish (i.e. look at the SYNOPSIS in how complicated it is to
402			get a specific set of warnings - it is not reasonable to put this into
403			every module, the maintenance effort would be enormous).
404
405			=item But many modules C<use strict> or C<use warnings>, so the memory
406			savings do not apply?
407
408			I suddenly feel sad...
409
410			But yes, that's true. Fortunately C<common::sense> still uses only a
411			miniscule amount of RAM.
412
413			=item But it adds another dependency to your modules!
414
415			It's a fact, yeah. But it's trivial to install, most popular modules have
416	root	1.2	many more dependencies. And we consider dependencies a good thing - it
417	root	1.1	leads to better APIs, more thought about interworking of modules and so
418			on.
419
420			=item Why do you use JSON and not YAML for your META.yml?
421
422			This is not true - YAML supports a large subset of JSON, and this subset
423			is what META.yml is written in, so it would be correct to say "the
424			META.yml is written in a common subset of YAML and JSON".
425
426			The META.yml follows the YAML, JSON and META.yml specifications, and is
427			correctly parsed by CPAN, so if you have trouble with it, the problem is
428			likely on your side.
429
430			=item But! But!
431
432			Yeah, we know.
433
434			=back
435
436			=head1 AUTHOR
437
438			Marc Lehmann <schmorp@schmorp.de>
439			http://home.schmorp.de/
440
441			Robin Redeker, "<elmex at ta-sa.org>".
442
443			=cut
444