1. Perl 5.16 and beyond
Jesse Vincent
jesse@perl.org
@obra

2. Perl 6
Recovering Perl 6
Project Manager

3. Perl 6
Recovering Perl 6
Project Manager

4. Perl 5
Perl 5 Pumpking

5. Perl 5
Perl 5 Pumpking

6. Perl 5
Perl 5 Pumpking

7. Perl 5
Perl 5 Pumpking
http://flic.kr/p/6StRmB

8. Perl 5
Perl 5 Pumpking

9. ?
What's a Pumpking?

10. BDFL

11. BDFL

12. BDFL

13. I make decisions

14. ( )
(the unpopular ones)

15. I delegate

16. ( )
(any real work)

17. I document

18. ( )
(process and policy)

19. I destress

20. ( )
(other people)

21. I’m a manager

22. Perl ?
So, who makes Perl?

23. Many awesome people

24. I just stand
around
looking
pretty...

25. ...while other people do
awesome stuff

26. Perl AUTHORS ?
Is your name in Perl’s
AUTHORS file?

27. CPAN ?
Are you a
CPAN author?

28. You rock

29. Perl
You make Perl

30. Perl
The rules of
Perl Club

31. commit e8cd7eae0498ecc1fd3801fe3160
Author: Gurusamy Sarathy <gsar@cpan.org>
Date: Sun Oct 10 23:48:07 1999 +0000
add perlhack.pod from Nathan Torkington
<gnat@frii.com>

32. 1
Rule 1

33. Perl
Larry is always
right about how
Perl should behave

34. 2
Rule 2

35. Larry is allowed to
change his mind
about any matter
at a later date...

36. ...regardless
of whether
he previously
invoked Rule 1

37. I’m not Larry

38. I’m nowhere
near as clever

39. My shirts are
nowhere near
as loud

40. My shirts are
nowhere near
as loud

41. The rules aren’t
just for Larry

42. The rules aren’t
just for the Pumpking

43. Perl 5
The rules also apply
to the Perl 5 core.

44. ?
What?

45. 1
Rule 1

46. Perl
Perl is always right!

47. ( )
(TMTOWTDI)

48. 2
Rule 2

49. Perl 5
The Perl 5 core
is allowed to...

50. ?
change its mind?

51. Changing our
minds is easy

52. We are very
good at it

53. Not flailing wildly when
we do has been hard

54. ...and leads to
problems

55. at least I haven’t
heard this
in a while...

56. Perl
Perl is Dead !

57. Perl
Perl is Dead !1!!

58. Perl
Perl is Dead !1!!one!

59. What I’ve been
hearing lately...

60. ?
Where are we going?

61. It’s changing too fast.
Can you slow down?

62. ?
You made regexes
crazier? /$#@!/l?

63. smartmatch isn’t
named correctly...

64. we should call it
psychoticmatch

65. ?
Now that it’s undead,
can we rename it?

66. I’ve been accused
of lacking a
vision for Perl 5

67. What
I lack
is a flame-proof suit
http://en.wikipedia.org/wiki/File:Dance_Dance_Immolation.jpg

68. pe
What rl5
I lack -po
rt
e rs
is a flame-proof suit
http://en.wikipedia.org/wiki/File:Dance_Dance_Immolation.jpg

69. 2
If I’d talked about my
vision 2 years ago...

70. You would have
laughed at me

71. Perl 5
Improving Perl 5
did not matter

72. We couldn’t even
put out a new release

73. In the past year...

74. 5
Five
Stable
Releases

75. 1
A dozen
development
releases

76. Perl 5.14.2
Perl 5.14.2 is the
current stable
release of Perl 5

77. 9
It came out in
September

78. 3
It used to take us
3 weeks to prepare
a release

79. We made the
Pumpking do it

80. 1
Now it takes
less than a day

81. 43
The 43 step process is
documented

82. We have rotating
release engineers

83. Many of them are
new committers

84. Release engineers
need commit bits

85. git
Since the switch to git,
we’ve nearly doubled
our committer list

86. The world
hasn’t ended

87. Some of those release
engineers have become
prolific contributors

88. Now that
releases
are easy...

89. Perl 5
A Vision for Perl 5

90. New versions of Perl 5
should not break
your existing software

91. Old syntax and
semantics
must not stop
Perl 5 from evolving

92. Perl 5
We need to be able to
make mistakes
as we rebuild Perl 5

93. We will
make mistakes
as we rebuild Perl 5

94. We have
made mistakes
as we’ve rebuilt Perl 5

95. We need to be able to
recover from mistakes
as we rebuild Perl 5

96. The runtime is
too big and must be
slimmed down

97. Perl should have
sane defaults

98. We need to be able to
recover from last
year’s “sane defaults”

99. Perl 5 Perl 5
It should be possible
to build more of
Perl 5 in Perl 5

100. Perl should run
everywhere

101. 2: Perl
Rule 2:
Perl is allowed to
change its mind

102. That’s already true

103. That hurts programs
and programmers

104. When your code runs,
you have no idea
what semantics it’ll see

105. use v5.14;

106. 5.14 Perl ?
“Can I have a Perl that’s
5.14 or newer?”

107. 5.14.0 !
“Anything newer than
5.14.0 would be
great!”

108. OK 5.30 !
“Ok. I’m 5.30.
Have fun!”

109. That is not useful

110. It needs to change

111. Perl 5
From now on, declare
the version of Perl 5
you expect

112. use v5.16;

113. 5.16 Perl 5
“I want a Perl 5 that
works like 5.16”

114. The runtime should
honor that request

115. Perl should give you
semantics as close as
possible to what you
request

116. New features
should not work
under ‘use v5.$older;’

117. It’s critical that we be
able to evolve

118. We need an
escape hatch

119. We need
Rule 2

120. If you declare an old
version, you get old
syntax and semantics

121. ...at least to the
best of our abilities

122. Perfection is
not possible

123. We can get far closer
than we do now

124. Breaking existing
code should be
a last resort

125. In limited
circumstances we will
break backward
compatibility

126. Some craziness can’t be
fixed in an “optional”
or lexical way

127. This is going to be
hard work

128. A lot of hard work

129. It’s not impossible

130. Deprecation

131. 1
Our current
deprecation cycle
is 1 year

132. 5.16.0
“It warns in 5.16.0”

133. 5.18.0
“It’s gone in 5.18.0”

134. That’s turning out
to be too short

135. OS
Very few operating
systems release that
frequently

136. Declare by default
means we can make
some changes sooner

137. If it still works in
old code, we get to
change it with no
deprecation cycle

138. Some misfeatures
need to come out
lest they block major
improvements

139. If we can’t emulate
an old feature for old
code, we get a longer
deprecation cycle

140. 'use v5.16' die
“It dies in code that
declares ‘use v5.16’”

141. 5.16.0
“It warns in older
code on 5.16.0”

142. 5.18.0
“It still warns in old
code on 5.18.0”

143. 5.20.0
“It’s gone in 5.20.0”

144. 2
Rule 2 and
Old Modules

145. We haven’t just been
deprecating and yanking
broken old features

146. We’ve been doing the
same to old modules

147. CPAN
They all end up
on CPAN

148. This hurts users who
wrote code with
“no non-core deps”

149. 2 Perl 5
We need to make it
easier to ship two
flavors of Perl 5

150. (Eagles)
Hotel California

151. Last thing I remember, I was
Running for the door
I had to find the passage back
To the place I was before
’relax,’ said the night man,
We are programmed to receive.
You can checkout any time you like,
But you can never leave!

152. Perl
aka Traditional Perl

153. (Bob Dylan)
The Times,They
Are A-Changin’

154. The line it is drawn
The curse it is cast
The slow one now
Will later be fast
As the present now
Will later be past
The order is rapidly fadin’
And the first one now will later be last
For the times they are a-changin’

155. Perl
aka Bootstrappable Perl

156. There’s work going on
to make this easier

157. Perl
Perl is a big language

158. There are bigger
languages

159. It's harder to manage
a big language

160. It’s harder to learn
a big language

161. It’s harder to fix bugs in
a big language

162. We’re ok, but not
amazing at core
language dev

163. Perl
As a community, we’re
awesome at modules

164. Perl
?
How do we make Perl
a smaller language?

165. It’s possible to load
modules that inject
new builtins

166. It’s possible to load
modules that inject
old builtins

167. Time to start...

168. ...refactoring

169. Lots of stuff in perl isn't
necessarily part of
Perl 5 the language

170. Perl 5
This stuff is part of
Perl 5 the chainsaw

171. I like our chainsaw

172. I’m not talking about
deprecating this stuff

173. ...just about
decoupling it

174. SysV IPC
SysV IPC functions

175. Socket IO
Socket IO functions

176. Unix /
Unix user & group
information functions

177. Unix
Unix network
information functions

178. Process and process
group functions

179. Formats

180. smartmatch

181. ...and probably a bunch
of other stuff

182. 'use v5.16'
5.14
If you don’t ‘use v5.16’,
you’ll get whatever was
in 5.14.

183. SysV
The implementation of
SysV might be a
module

184. As a Perl 5 user you
won’t need to care

185. ..and shouldn’t
be able to tell

186. In the future we might
fix a bug or two in the
modularized code

187. Perl 5
You could take the
update without
having to upgrade all of
Perl 5

188. Someday we might
remove things from the
default runtime

189. Every feature we
externalize reclaims
precious memory

190. Every feature we
externalize reclaims
precious sanity

191. That just means you’ll
need to declare you
want an older feature

192. v5.16
...but only if you
ask for v5.16

193. v5.18
...but only if you
ask for v5.18

194. v5.20
...but only if you
ask for v5.20

195. Existing code
won’t break

196. There are many, many
unanswered
questions

197. But it’s doable

198. Perl
We've been moving
pretty fast

199. We’ve done some
things I...

200. would not
do again

201. I’m going to be a lot
more skeptical about
new features

202. ...at least ones that
don’t make it easier to
have fewer features

203. We should have
sane defaults

204. Perl 5
There’s lots of crazy
in Perl 5

205. Syntactic Crazy

206. Semantic Crazy

207. Internal Crazy

208. Module Crazy

209. It may be time to
consider doing away
with some of that

210. We’ve started
down this road

211. "use v5.12" "use strict;"
“use v5.12”
includes
“use strict;”

212. ?
Where do we
go next?

213. warnings
warnings on
by default

214. autodie
autodie-esque
defaults

215. return
We should throw
exceptions rather
than just return on
failure

216. I don’t want us to
bikeshed an
exception hierarchy

217. Heck, I’d be happy if we
started with dying with
well-defined strings

218. ( )
(I’d love an exception hierarchy)

219. 2 open()
2-arg open()
gone by default

220. 1 open()
1-arg open()
gone by default

221. No more ' package
separator

222. Latin-1
Latin-1
autopromote
off by default

223. utf-8
utf-8 everything
by default

224. A clean, simple
meta-model
with classes
and methods

225. No indirect object
syntax by default

226. "use v5.16"
But only if you declare
“use v5.16”

227. "use v5.18"
But only if you declare
“use v5.18”

228. "use v5.20"
But only if you declare
“use v5.20”

229. Perl
Perl needs to be
cleaner, simpler
and easier
to work with

230. For users...

231. ...and for
implementers

232. Perl
Perl should run
everywhere

233. Not just on every
kind of hardware

234. OS
Not just on every
Operating System

235. VM
Every VM

236. Every Browser

237. Every Phone

238. Perl 5 ?
Why isn’t Perl 5 on
other runtimes?

239. “There’s no spec”

240. Ruby
That didn’t stop Ruby

241. Perl 5 Perl 5
“Only Perl 5 can
parse Perl 5”

242. PPI
That didn't stop PPI

243. Perl 5
To survive, a desperate
hacker needs to be able
to reimplement Perl 5

244. Thanks!

245. Super-thanks
individual
sponsors!

246. Questions?
http://blog.fsck.com
jesse@perl.org
@obra

247. ?
So, you want
to change
the name?

248. Perl 7 ?
To something like
Perl 7?

249. Or Raptor?

250. Perl 5
Our language
is called
Perl 5

251. Perl 6
Perl 6 is our
precocious
kid sister

252. Perl 5
I’m happy to talk about
renaming Perl 5...

253. ...if you write me a
second implementation

254. ...that passes the
test suite