common-sense/sense.pm.PL

#! perl-000

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

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

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

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

__DATA__

=head1 NAME

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

=head1 SYNOPSIS

 use common::sense;

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


=head1 DESCRIPTION

   “Nothing is more fairly distributed than common sense: no one thinks
   he needs more of it than he already has.”

   – René Descartes

This module implements some sane defaults for Perl programs, as defined by
two typical (or not so typical - use your common sense) specimens of Perl
coders. In fact, after working out details on which warnings and strict
modes to enable and make fatal, we found that we (and our code written so
far, and others) fully agree on every option, even though we never used
warnings before, so it seems this module indeed reflects a "common" sense
among some long-time Perl coders.

The basic philosophy behind the choices made in common::sense can be
summarised as: "enforcing strict policies to catch as many bugs as
possible, while at the same time, not limiting the expressive power
available to the programmer".

Two typical examples of how this philosophy is applied in practise is the
handling of uninitialised and malloc warnings:

=over 4

=item I<uninitialised>

C<undef> is a well-defined feature of perl, and enabling warnings for
using it rarely catches any bugs, but considerably limits you in what you
can do, so uninitialised warnings are disabled.

=item I<malloc>

Freeing something twice on the C level is a serious bug, usually causing
memory corruption. It often leads to side effects much later in the
program and there are no advantages to not reporting this, so malloc
warnings are fatal by default.

=back

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.


=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 = '3.5';

# overload should be included

sub import {
   local $^W; # work around perl 5.16 spewing out warnings for next line
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. :("

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 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:	1.9
Committed:	Sat Mar 24 12:46:11 2012 UTC (12 years, 2 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-3_5
Changes since 1.8:	+2 -1 lines
Log Message:	3.5
#	Content
1	#! perl-000
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	use warnings qw(FATAL closed threads internal debugging pack malloc portable prototype
19	inplace io pipe unpack deprecated glob digit printf
20	layer reserved taint closure semicolon);
21	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	# use warnings qw(FATAL closed threads internal debugging pack
60	# portable prototype inplace io pipe unpack malloc
61	# deprecated glob digit printf layer
62	# reserved taint closure semicolon);
63	# no warnings qw(exec newline unopened);
64
65
66	=head1 DESCRIPTION
67
68	“Nothing is more fairly distributed than common sense: no one thinks
69	he needs more of it than he already has.”
70
71	– René Descartes
72
73	This module implements some sane defaults for Perl programs, as defined by
74	two typical (or not so typical - use your common sense) specimens of Perl
75	coders. In fact, after working out details on which warnings and strict
76	modes to enable and make fatal, we found that we (and our code written so
77	far, and others) fully agree on every option, even though we never used
78	warnings before, so it seems this module indeed reflects a "common" sense
79	among some long-time Perl coders.
80
81	The basic philosophy behind the choices made in common::sense can be
82	summarised as: "enforcing strict policies to catch as many bugs as
83	possible, while at the same time, not limiting the expressive power
84	available to the programmer".
85
86	Two typical examples of how this philosophy is applied in practise is the
87	handling of uninitialised and malloc warnings:
88
89	=over 4
90
91	=item I<uninitialised>
92
93	C<undef> is a well-defined feature of perl, and enabling warnings for
94	using it rarely catches any bugs, but considerably limits you in what you
95	can do, so uninitialised warnings are disabled.
96
97	=item I<malloc>
98
99	Freeing something twice on the C level is a serious bug, usually causing
100	memory corruption. It often leads to side effects much later in the
101	program and there are no advantages to not reporting this, so malloc
102	warnings are fatal by default.
103
104	=back
105
106	Unfortunately, there is no fine-grained warning control in perl, so often
107	whole groups of useful warnings had to be excluded because of a single
108	useless warning (for example, perl puts an arbitrary limit on the length
109	of text you can match with some regexes before emitting a warning, making
110	the whole C<regexp> category useless).
111
112	What follows is a more thorough discussion of what this module does,
113	and why it does it, and what the advantages (and disadvantages) of this
114	approach are.
115
116	=head1 RATIONALE
117
118	=over 4
119
120	=item use utf8
121
122	While it's not common sense to write your programs in UTF-8, it's quickly
123	becoming the most common encoding, is the designated future default
124	encoding for perl sources, and the most convenient encoding available
125	(you can do really nice quoting tricks...). Experience has shown that our
126	programs were either all pure ascii or utf-8, both of which will stay the
127	same.
128
129	There are few drawbacks to enabling UTF-8 source code by default (mainly
130	some speed hits due to bugs in older versions of perl), so this module
131	enables UTF-8 source code encoding by default.
132
133
134	=item use strict qw(subs vars)
135
136	Using C<use strict> is definitely common sense, but C<use strict
137	'refs'> definitely overshoots its usefulness. After almost two
138	decades of Perl hacking, we decided that it does more harm than being
139	useful. Specifically, constructs like these:
140
141	@{ $var->[0] }
142
143	Must be written like this (or similarly), when C<use strict 'refs'> is in
144	scope, and C<$var> can legally be C<undef>:
145
146	@{ $var->[0] \|\| [] }
147
148	This is annoying, and doesn't shield against obvious mistakes such as
149	using C<"">, so one would even have to write (at least for the time
150	being):
151
152	@{ defined $var->[0] ? $var->[0] : [] }
153
154	... which nobody with a bit of common sense would consider
155	writing: clear code is clearly something else.
156
157	Curiously enough, sometimes perl is not so strict, as this works even with
158	C<use strict> in scope:
159
160	for (@{ $var->[0] }) { ...
161
162	If that isn't hypocrisy! And all that from a mere program!
163
164
165	=item use feature qw(say state given)
166
167	We found it annoying that we always have to enable extra features. If
168	something breaks because it didn't anticipate future changes, so be
169	it. 5.10 broke almost all our XS modules and nobody cared either (or at
170	least I know of nobody who really complained about gratuitous changes -
171	as opposed to bugs).
172
173	Few modules that are not actively maintained work with newer versions of
174	Perl, regardless of use feature or not, so a new major perl release means
175	changes to many modules - new keywords are just the tip of the iceberg.
176
177	If your code isn't alive, it's dead, Jim - be an active maintainer.
178
179	But nobody forces you to use those extra features in modules meant for
180	older versions of perl - common::sense of course works there as well.
181	There is also an important other mode where having additional features by
182	default is useful: commandline hacks and internal use scripts: See "much
183	reduced typing", below.
184
185
186	=item no warnings, but a lot of new errors
187
188	Ah, the dreaded warnings. Even worse, the horribly dreaded C<-w>
189	switch: Even though we don't care if other people use warnings (and
190	certainly there are useful ones), a lot of warnings simply go against the
191	spirit of Perl.
192
193	Most prominently, the warnings related to C<undef>. There is nothing wrong
194	with C<undef>: it has well-defined semantics, it is useful, and spitting
195	out warnings you never asked for is just evil.
196
197	The result was that every one of our modules did C<no warnings> in the
198	past, to avoid somebody accidentally using and forcing his bad standards
199	on our code. Of course, this switched off all warnings, even the useful
200	ones. Not a good situation. Really, the C<-w> switch should only enable
201	warnings for the main program only.
202
203	Funnily enough, L<perllexwarn> explicitly mentions C<-w> (and not in a
204	favourable way, calling it outright "wrong"), but standard utilities, such
205	as L<prove>, or MakeMaker when running C<make test>, still enable them
206	blindly.
207
208	For version 2 of common::sense, we finally sat down a few hours and went
209	through I<every single warning message>, identifiying - according to
210	common sense - all the useful ones.
211
212	This resulted in the rather impressive list in the SYNOPSIS. When we
213	weren't sure, we didn't include the warning, so the list might grow in
214	the future (we might have made a mistake, too, so the list might shrink
215	as well).
216
217	Note the presence of C<FATAL> in the list: we do not think that the
218	conditions caught by these warnings are worthy of a warning, we I<insist>
219	that they are worthy of I<stopping> your program, I<instantly>. They are
220	I<bugs>!
221
222	Therefore we consider C<common::sense> to be much stricter than C<use
223	warnings>, which is good if you are into strict things (we are not,
224	actually, but these things tend to be subjective).
225
226	After deciding on the list, we ran the module against all of our code that
227	uses C<common::sense> (that is almost all of our code), and found only one
228	occurence where one of them caused a problem: one of elmex's (unreleased)
229	modules contained:
230
231	$fmt =~ s/([^\s\[])\[( [^\]] )\]/\x0$1\x1$2\x0/xgo;
232
233	We quickly agreed that indeed the code should be changed, even though it
234	happened to do the right thing when the warning was switched off.
235
236
237	=item much reduced typing
238
239	Especially with version 2.0 of common::sense, the amount of boilerplate
240	code you need to add to gte I<this> policy is daunting. Nobody would write
241	this out in throwaway scripts, commandline hacks or in quick internal-use
242	scripts.
243
244	By using common::sense you get a defined set of policies (ours, but maybe
245	yours, too, if you accept them), and they are easy to apply to your
246	scripts: typing C<use common::sense;> is even shorter than C<use warnings;
247	use strict; use feature ...>.
248
249	And you can immediately use the features of your installed perl, which
250	is more difficult in code you release, but not usually an issue for
251	internal-use code (downgrades of your production perl should be rare,
252	right?).
253
254
255	=item mucho reduced memory usage
256
257	Just using all those pragmas mentioned in the SYNOPSIS together wastes
258	<blink>I<< B<776> kilobytes >></blink> of precious memory in my perl, for
259	I<every single perl process using our code>, which on our machines, is a
260	lot. In comparison, this module only uses I<< B<four> >> kilobytes (I even
261	had to write it out so it looks like more) of memory on the same platform.
262
263	The money/time/effort/electricity invested in these gigabytes (probably
264	petabytes globally!) of wasted memory could easily save 42 trees, and a
265	kitten!
266
267	Unfortunately, until everybods applies more common sense, there will still
268	often be modules that pull in the monster pragmas. But one can hope...
269
270	=cut
271
272	package common::sense;
273
274	our $VERSION = '3.5';
275
276	# overload should be included
277
278	sub import {
279	local $^W; # work around perl 5.16 spewing out warnings for next line
280	IMPORT
281	# use feature
282	$^H{feature_switch} =
283	$^H{feature_say} =
284	$^H{feature_state} = 1;
285	}
286
287	1;
288
289	=back
290
291	=head1 THERE IS NO 'no common::sense'!!!! !!!! !!
292
293	This module doesn't offer an unimport. First of all, it wastes even more
294	memory, second, and more importantly, who with even a bit of common sense
295	would want no common sense?
296
297	=head1 STABILITY AND FUTURE VERSIONS
298
299	Future versions might change just about everything in this module. We
300	might test our modules and upload new ones working with newer versions of
301	this module, and leave you standing in the rain because we didn't tell
302	you. In fact, we did so when switching from 1.0 to 2.0, which enabled gobs
303	of warnings, and made them FATAL on top.
304
305	Maybe we will load some nifty modules that try to emulate C<say> or so
306	with perls older than 5.10 (this module, of course, should work with older
307	perl versions - supporting 5.8 for example is just common sense at this
308	time. Maybe not in the future, but of course you can trust our common
309	sense to be consistent with, uhm, our opinion).
310
311	=head1 WHAT OTHER PEOPLE HAD TO SAY ABOUT THIS MODULE
312
313	apeiron
314
315	"... wow"
316	"I hope common::sense is a joke."
317
318	crab
319
320	"i wonder how it would be if joerg schilling wrote perl modules."
321
322	Adam Kennedy
323
324	"Very interesting, efficient, and potentially something I'd use all the time."
325	[...]
326	"So no common::sense for me, alas."
327
328	H.Merijn Brand
329
330	"Just one more reason to drop JSON::XS from my distribution list"
331
332	Pista Palo
333
334	"Something in short supply these days..."
335
336	Steffen Schwigon
337
338	"This module is quite for sure not just a repetition of all the other
339	'use strict, use warnings'-approaches, and it's also not the opposite.
340	[...] And for its chosen middle-way it's also not the worst name ever.
341	And everything is documented."
342
343	BKB
344
345	"[Deleted - thanks to Steffen Schwigon for pointing out this review was
346	in error.]"
347
348	Somni
349
350	"the arrogance of the guy"
351	"I swear he tacked somenoe else's name onto the module
352	just so he could use the royal 'we' in the documentation"
353
354	Anonymous Monk
355
356	"You just gotta love this thing, its got META.json!!!"
357
358	dngor
359
360	"Heh. '"<elmex at ta-sa.org>"' The quotes are semantic
361	distancing from that e-mail address."
362
363	Jerad Pierce
364
365	"Awful name (not a proper pragma), and the SYNOPSIS doesn't tell you
366	anything either. Nor is it clear what features have to do with "common
367	sense" or discipline."
368
369	acme
370
371	"THERE IS NO 'no common::sense'!!!! !!!! !!"
372
373	apeiron (meta-comment about us commenting^Wquoting his comment)
374
375	"How about quoting this: get a clue, you fucktarded amoeba."
376
377	quanth
378
379	"common sense is beautiful, json::xs is fast, Anyevent, EV are fast and
380	furious. I love mlehmannware ;)"
381
382	apeiron
383
384	"... it's mlehmann's view of what common sense is. His view of common
385	sense is certainly uncommon, insofar as anyone with a clue disagrees
386	with him."
387
388	apeiron (another meta-comment)
389
390	"apeiron wonders if his little informant is here to steal more quotes"
391
392	ew73
393
394	"... I never got past the SYNOPSIS before calling it shit."
395	[...]
396	How come no one ever quotes me. :("
397
398	chip (not willing to explain his cryptic questions about links in Changes files)
399
400	"I'm willing to ask the question I've asked. I'm not willing to go
401	through the whole dance you apparently have choreographed. Either
402	answer the completely obvious question, or tell me to fuck off again."
403
404	=head1 FREQUENTLY ASKED QUESTIONS
405
406	Or frequently-come-up confusions.
407
408	=over 4
409
410	=item Is this module meant to be serious?
411
412	Yes, we would have put it under the C<Acme::> namespace otherwise.
413
414	=item But the manpage is written in a funny/stupid/... way?
415
416	This was meant to make it clear that our common sense is a subjective
417	thing and other people can use their own notions, taking the steam out
418	of anybody who might be offended (as some people are always offended no
419	matter what you do).
420
421	This was a failure.
422
423	But we hope the manpage still is somewhat entertaining even though it
424	explains boring rationale.
425
426	=item Why do you impose your conventions on my code?
427
428	For some reason people keep thinking that C<common::sense> imposes
429	process-wide limits, even though the SYNOPSIS makes it clear that it works
430	like other similar modules - i.e. only within the scope that C<use>s them.
431
432	So, no, we don't - nobody is forced to use this module, and using a module
433	that relies on common::sense does not impose anything on you.
434
435	=item Why do you think only your notion of common::sense is valid?
436
437	Well, we don't, and have clearly written this in the documentation to
438	every single release. We were just faster than anybody else w.r.t. to
439	grabbing the namespace.
440
441	=item But everybody knows that you have to use strict and use warnings,
442	why do you disable them?
443
444	Well, we don't do this either - we selectively disagree with the
445	usefulness of some warnings over others. This module is aimed at
446	experienced Perl programmers, not people migrating from other languages
447	who might be surprised about stuff such as C<undef>. On the other hand,
448	this does not exclude the usefulness of this module for total newbies, due
449	to its strictness in enforcing policy, while at the same time not limiting
450	the expressive power of perl.
451
452	This module is considerably I<more> strict than the canonical C<use
453	strict; use warnings>, as it makes all its warnings fatal in nature, so
454	you can not get away with as many things as with the canonical approach.
455
456	This was not implemented in version 1.0 because of the daunting number
457	of warning categories and the difficulty in getting exactly the set of
458	warnings you wish (i.e. look at the SYNOPSIS in how complicated it is to
459	get a specific set of warnings - it is not reasonable to put this into
460	every module, the maintenance effort would be enourmous).
461
462	=item But many modules C<use strict> or C<use warnings>, so the memory
463	savings do not apply?
464
465	I suddenly feel sad...
466
467	But yes, that's true. Fortunately C<common::sense> still uses only a
468	miniscule amount of RAM.
469
470	=item But it adds another dependency to your modules!
471
472	It's a fact, yeah. But it's trivial to install, most popular modules have
473	many more dependencies and we consider dependencies a good thing - it
474	leads to better APIs, more thought about interworking of modules and so
475	on.
476
477	=item Why do you use JSON and not YAML for your META.yml?
478
479	This is not true - YAML supports a large subset of JSON, and this subset
480	is what META.yml is written in, so it would be correct to say "the
481	META.yml is written in a common subset of YAML and JSON".
482
483	The META.yml follows the YAML, JSON and META.yml specifications, and is
484	correctly parsed by CPAN, so if you have trouble with it, the problem is
485	likely on your side.
486
487	=item But! But!
488
489	Yeah, we know.
490
491	=back
492
493	=head1 AUTHOR
494
495	Marc Lehmann <schmorp@schmorp.de>
496	http://home.schmorp.de/
497
498	Robin Redeker, "<elmex at ta-sa.org>".
499
500	=cut
501