Pharo is an open-source live-programming environment and programming language started in 2008. The official web site is http://www.pharo-project.org. By providing a stable and small core system, excellent dev tools, and maintained releases, Pharo is an attractive platform to build and deploy mission-critical applications.

1. Pharo:
A malleable and powerful
platform
Damien Cassou and Camille Teruel
http://www.pharo.org

2. What is it?
Programming language + IDE
Object-Oriented, Dynamic, Reflective
Explore + Change running systems
The Ultimate Live Programming
Environment!

3. Pharo
MIT license
Great community of active doers
Powerful
Elegant and fun to program
Living system under your fingers
Mac, Linux, Android, iOS, Windows

4. 2nd most downloaded on Inria gforge
40-50 active commiters
> 600 mailing-list members
180 license agreements
50 association members
17 industrial consortium members
around 300 external projects
Pharo in numbers
Very High
Activity

6. Create an ecosystem
where business/innovation
can bloom

7. We want that you can make research
and money with Pharo.
We want a powerful innovative
dynamic language where we can build
our future.

8. A Little Journey in the Pharo
Object Model

9. A pure and minimal object model
Less is more!

10. No constructors, no static methods, no operators
No interfaces, no private/protected modifiers
No type declarations, no parametrized types
No primitive types, no boxing/unboxing
Still powerful

11. Everything is an object

12. 213 class
SmallInteger
Objects are instances of
Classes
class is a message sent
to the object 213
SmallInteger is the
result of the message sent
In “Java”:
213.getClass()

13. Objects are instances of
Classes
Integer
SmallInteger
213
instance of
inherits
from

14. Sending a message
Integer
SmallInteger
213
factorial
instance of
inherits
from

15. Classes are objects too
213 class selectors
#(#instVarAt: #sizeInMemory
#printOn:base:length:padded: #< #bitXor: #''
#numberOfDigitsInBase: #'//' #threeDigitName
#highBitOfPositiveReceiver #bitAnd: #isLarge
#largeIdentityHash #'>=' #nextObject #nextInstance
#gcd: #printStringBase: #lowBit #pointsTo:
#basicIdentityHash #fromString:radix: ...)

16. Classes are objects too
Number allSubclasses
an OrderedCollection(Fraction Float Integer
ScaledDecimal SmallInteger LargePositiveInteger
LargeNegativeInteger)

17. Fun with Numbers!

18. 1 class
SmallInteger

19. 1 class
SmallInteger
1 class maxVal
1073741823

20. 1 class
SmallInteger
1 class maxVal
1073741823
1 class maxVal + 1
1073741824

21. 1 class
SmallInteger
1 class maxVal
1073741823
1 class maxVal + 1
1073741824
(1 class maxVal + 1) class
LargePositiveInteger

22. (1/3) + (2/3)
1

23. (1/3) + (2/3)
1
2/3 + 1
5/3

24. (1/3) + (2/3)
1
2/3 + 1
5/3
1000 factorial
4023872600770937735437024339230039857193748642107146325437999104299385123986290205920442084869694048004799886101971960586316668729948085589013238296699445
9099742450408707375991882362772718873251977950595099527612087497546249704360141827809464649629105639388743788648733711918104582578364784997701247663288983
5955735432513185323958463075557409114262417474349347553428646576611667797396668820291207379143853719588249808126867838374559731746136085379534524221586593
2019280908782973084313928444032812315586110369768013573042161687476096758713483120254785893207671691324484262361314125087802080002616831510273418279777047
8463586817016436502415369139828126481021309276124489635992870511496497541990934222156683257208082133318611681155361583654698404670897560290095053761647584
7728421889679646244945160765353408198901385442487984959953319101723355556602139450399736280750137837615307127761926849034352625200015888535147331611702103
9681759215109077880193931781141945452572238655414610628921879602238389714760885062768629671466746975629112340824392081601537808898939645182632436716167621
7916890977991190375403127462228998800519544441428201218736174599264295658174662830295557029902432415318161721046583203678690611726015878352075151628422554
0265170483304226143974286933061690897968482590125458327168226458066526769958652682272807075781391858178889652208164348344825993266043367660176999612831860
7883861502794659551311565520360939881806121385586003014356945272242063446317974605946825731037900840244324384656572450144028218852524709351906209290231364
9327349756551395872055965422874977401141334696271542284586237738753823048386568897646192738381490014076731044664025989949022222176590433990188601856652648
5061799702356193897017860040811889729918311021171229845901641921068884387121855646124960798722908519296819372388642614839657382291123125024186649353143970
1374285319266498753372189406942814341185201580141233448280150513996942901534830776445690990731524332782882698646027898643211390835062170950025973898635542
7719674282224875758676575234422020757363056949882508796892816275384886339690995982628095612145099487170124451646126037902930912088908694202851064018215439
9457156805941872748998094254742173582401063677404595741785160829230135358081840096996372524230560855903700624271243416909004153690105933983835777939410970
0277534720000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

25. Point class
Point class
Classes are objects too

26. Point class
Point class
Classes are objects too
“Point class” is an anonymous class
with only one instance: Point.
We call such classes “metaclasses”

27. Integer
SmallInteger
Class Parallel Inheritance
213
instance of

28. Integer
SmallInteger
Integer class
SmallInteger class
Class Parallel Inheritance
213
instance of
instance of
instance
of

29. Integer
SmallInteger
Integer class
SmallInteger class
A “static” method
is just a method of
the metaclass
Integer readFrom: '123'
123
Class Parallel Inheritance
factorial
class
class
readFrom:

30. Class extensions
A method can be defined in a class that
belongs to another package!
Powerful to build DSLs
$x ctrl , $f ctrl
Ctrl + X , Ctrl + F
ctrl method in
Character class

31. Summary
Everything is an object
One single model
Classes are objects too
A class is instance of another class
One unique method lookup, look in the
class of the receiver

32. Pharo: Syntax in a
Nutshell

33. asm
push: asm RBP;
mov: asm RSP -> asm RBP;
mov: 1024 -> asm RAX;
mov: asm RBP -> asm RSP;
pop: asm RBP;
ret.
identifier := #letter asParser ,
#word asParser star
Assembly
Parsers
Syntax Examples

34. Syntax on a PostCard
exampleWithNumber: x
|y|
true & false not & (nil isNil)
ifFalse: [ self halt ].
y := self size + super size.
{ 1 . 2 . #($a #a ‘a’ 1 1.0) }
do: [ :each |
Transcript
show: (each class name);
show: (each printString);
show: ‘ ‘ ].
^ x < y

35. Language Constructs
^ return
“
comments
# symbol or array
‘
string
[] block
. separator
; cascade
| local or block variable
:= assignment
$ character
<...> annotation

36. Examples
comment:
“a comment”
character: $c $.
string: 'a nice string' 'lulu' 'l''idiot'
symbol: #mac #+
array: { 1 . 123 + 1 }
literal array: #(1 2 3 (1 3) $a 4)
byte array: #[1 2 3]
block: [ :x | x * 2 ]
integer: 1 2r101
real: 1.5 6.03e-34 4 2.4e7
keywords: true false nil self super thisContext

37. Not Syntax
& conjunction (and)
| disjunction (or)
+ addition
< lower than
ifTrue: condition
do: iteration
...
all of these are
plain methods!

38. Not Syntax
& conjunction (and)
| disjunction (or)
+ addition
< lower than
ifTrue: condition
do: iteration
...
Boolean>>
Boolean>>
Number>>
Magnitude>>
Boolean>>
Collection>>
their
classes
3 = 2
ifTrue: [
Error signal: 'Help' ]

39. 3 kinds of messages
Unary messages
Binary messages
Keywords messages
5 factorial
Transcript cr
3 + 4
2 between: 0 and: 5
Transcript show: 'hello world'

40. postman.send( mail, recipient);
Keyword messages

41. postman.send( mail, recipient);
Keyword messages

42. postman send mail recipient
Keyword messages

43. postman send mail to recipient
Keyword messages

44. postman send: mail to: recipient
Keyword messages

45. postman send: mail to: recipient
Keyword messages
send:to: method in the
Postman class
receiver argument 1 argument 2
message send

46. strings := OrderedCollection new
ArrayList<String> strings = new
ArrayList<String>();
Some Comparisons

47. persons collect: [:person | person name]
ArrayList<String> strings
= new ArrayList<String>();
for(Person person: persons) {
strings.add(person.name());
}
Some Comparisons

48. persons collect: #name
ArrayList<String> strings
= new ArrayList<String>();
for(Person person: persons) {
strings.add(person.name());
}
Some Comparisons

49. [ self doSomething ] fork
new Thread(
new Runnable() {
public void run() {
this.doSomething();}}).start();
Some Comparisons

50. (10 between: 1 and: 20 + 2) not
false
( ) > Unary > Binary > Keywords

51. A method definition in Point
Method name
<= aPoint
"Answer whether the receiver is neither
below nor to the right of aPoint."
^ x <= aPoint x and: [y <= aPoint y]
(2@3) <= (5@6)
true

52. A method definition in Point
Argument
<= aPoint
"Answer whether the receiver is neither
below nor to the right of aPoint."
^ x <= aPoint x and: [y <= aPoint y]
(2@3) <= (5@6)
true

53. A method definition in Point
Comment
<= aPoint
"Answer whether the receiver is neither
below nor to the right of aPoint."
^ x <= aPoint x and: [y <= aPoint y]
(2@3) <= (5@6)
true

54. A method definition in Point
Return
<= aPoint
"Answer whether the receiver is neither
below nor to the right of aPoint."
^ x <= aPoint x and: [y <= aPoint y]
(2@3) <= (5@6)
true

55. A method definition in Point
Instance variable
<= aPoint
"Answer whether the receiver is neither
below nor to the right of aPoint."
^ x <= aPoint x and: [y <= aPoint y]
(2@3) <= (5@6)
true

56. A method definition in Point
Binary message
<= aPoint
"Answer whether the receiver is neither
below nor to the right of aPoint."
^ x <= aPoint x and: [y <= aPoint y]
(2@3) <= (5@6)
true

57. A method definition in Point
Keyword message
<= aPoint
"Answer whether the receiver is neither
below nor to the right of aPoint."
^ x <= aPoint x and: [y <= aPoint y]
(2@3) <= (5@6)
true

58. A method definition in Point
Block
<= aPoint
"Answer whether the receiver is neither
below nor to the right of aPoint."
^ x <= aPoint x and: [y <= aPoint y]
(2@3) <= (5@6)
true

59. Point>> <= aPoint
"Answer whether the receiver is neither
below nor to the right of aPoint."
^ x <= aPoint x and: [y <= aPoint y]
in books and slides, we
specify the class name
Class name

60. Statements and Cascades
Temporary variables Statement
Cascade
| p pen |
p := 100@100.
pen := Pen new.
pen
up;
goto: p;
down;
goto: p+p

61. Anonymous method
Passed as method argument or stored
f := [:x | x * x + 3].
f value: 2
7
Blocks (aka Closure)
BlockClosure>>value:

62. Block usage
Integer>> factorial
self = 0
ifTrue: [ ^ 1 ].
self > 0
ifTrue: [ ^ self * (self - 1) factorial ]
#(1 2 3) do: [ :each | each crLog ]

63. Control Structures
Every control structure is realized by message sends
[ stream atEnd ]
whileFalse: [ self process: stream next ].
Magnitude>> max: aMagniture
^ self > aMagnitude
ifTrue: [ self ]
ifFalse: [ aMagnitude ]

64. Iterating Collections
#(2 3 4 -35 4)
collect: [ :each| each abs ]
#(2 3 4 35 4)

65. Iterating Collections
#(2 3 4 -35 4)
select: [ :each| each odd ]
#(-3 -35)

66. Iterating Collections
#(2 3 4 -35 4)
do: [ :each| Transcript crShow: each ]
2
3
...

67. Pharo, a live programming
environment

68. Demo
Modifying classes and methods while
the program is running

69. Nice libraries and
frameworks

70. 'http://picasaweb.google.com/data/feed/
api/all?q=puppy' asUrl retrieveContents

71. Gofer new
smalltalkhubUser: 'PharoExtras'
project: 'XMLParser';
loadStable.

72. data := 'http://picasaweb.google.com/data/
feed/api/all?q=puppy' asUrl retrieveContents.
doc := XMLDOMParser parse: data

73. data := 'http://picasaweb.google.com/data/
feed/api/all?q=puppy' asUrl retrieveContents.
doc := XMLDOMParser parse: data.
entries := doc
allNodesSelect: [ :n | n name = 'entry' ].
entry := entries anyOne.
content := entry
nodesDetect: [ :n | n name = 'content'].
url := content attributeAt: 'src'.
'http://lh3.ggpht.com/[...]/puppy-and-kitten.jpg'

74. data := 'http://picasaweb.google.com/data/
feed/api/all?q=puppy' asUrl retrieveContents.
doc := XMLDOMParser parse: data.
path := XPath for: 'entry/content/@src'.
urls := path in: doc.
url := urls anyOne.
'http://lh3.ggpht.com/[...]/puppy-and-kitten.jpg'

75. (ZnEasy getGif: url) asMorph openInHand

76. Your turn

77. Black magic

78. Execution Stack as an Object
To define exceptions from within the language
Debugger support!
Advanced debugging
Continuation

79. thisContext
returns an object that represents the
method invocation
can walk (even modify!) the stack

80. Serializing Continuations
[ "some code causing an error" ]
on: Error
do: [ :error |
FLSerializer
serialize: error
toFileNamed: 'error.fuel' ]
Then in a new image open a debugger on the serialized error:
FLMaterializer
materializeFromFileNamed: 'error.fuel';
debug.

81. Powerful Breakpoints?
Would be so good if we could say:
“Stop method bar only if it is called from
method named foo” i.e.,
bar
...
Halt whenCalledFrom: #foo.
...

82. Halt>> whenCalledFrom: aSelector
| ctxt |
ctxt := thisContext.
[ ctxt sender isNil ]
whileFalse: [
ctxt := ctxt sender.
ctxt selector = aSelector
ifTrue: [ self signal ] ]

83. Pointer Swapping
anObject become: anotherObject

84. | pt1 pt2 ref |
pt1 := 0@0.
pt2 := 100@100.
ref := pt1.
pt1 become: pt2.
self assert: ref = (100@100).
self assert: pt2 = (0@0).
self assert: pt1 = (100@100).
Pointer Swapping

85. Some Pharo’s success
stories

88. Continuous API Testing
keep your services under control 24/7
Norbert Hartl norbert@2denker.de
www.2denker.de

89. WEBDRUCK.CH
Web-To-Print Solution
• Design and create
individual printed
matter
• eShop with credit
card payment
• High quality PDF
output with Printing
Process integration
• Thousands of orders
for seven Swiss
printing companies

90. NTed: disaster scenario
recovery

91. iBizLog - http://www.ibizlog.com
A product by Smallworks
Tuesday, May 15, 12

94. Pinesoft MBagger

95. We want more success
stories!

96. We are a cool community

97. www.10pines.com
www.2denker.de
www.agilitic.com
www.airflowing.com
www.anymorphic.com
www.ardishealth.com
www.beta9.be
www.bombardier.com
www.cmsbox.com
www.finworks.biz
seaside.gemstone.com
www.ibizlog.com
www.inceptive.be
www.jooshr.com
www.majcon.de
www.mindclue.ch
www.miriamtech.com
www.myneat.org
www.netstyle.ch
www.objectfusion.fr
www.panasoft.com
www.pinesoft.co.uk
www.promedmedical.net
www.sharedlogic.ca
www.smallworks.com.ar
www.trantaria.com
www.square-i.net
yesplan.be
Companies

98. University of Bueno Aires
University of Bern scg.unibe.ch
University of Brussels soft.vub.ac.be/soft/
Ecole des Mines www.ensm-douai.fr
Université de Savoie www.imus.univ-savoie.fr
Ivan Franko National University of Ukraine
Czech Technical University
University of Life Sciences in Prague
Northen Michigan University www.nmu.edu
University Catholic of Argentina www.uca.edu.ar
University of Santiago www.uchile.cl
Universitat Policnica de Catalunya www.upc.edu
Lectures

99. Lafhis (University of Bueno Aires )
Software Composition Group (scg.unibe.ch)
CAR (Ecole des mines www.ensm-douai.fr)
RMoD (Inria)
Ummisco (IRD)
Reveal (University of Lugano)
Lysic (University of Bretagne Occidentale)
Pleiad (University of Santiago)
CEA-List
Research Groups

100. Community Ongoing Work
Better widgets, UI Builder (A. Plantec, G. Chambers, B. van Ryseghem)
Better browsers (B. van Ryseghem, C. Bruni)
Proxy (M. Martinez-Peck)
New compiler (J. Ressia/M. Denker/C. Bera/)
Vectorial canvas (I. Stasenko)
Better FFI (I. Stasenko, E. Lorenzano)
Bootstrap (G. Polito/S. Ducasse/N. Bouraqadi/L. Fabresse)
PDF generation (O. Auverlot, G. Larcheveque)
Network (WebSocket, Oauth, Zinc, Zodiac S. van Caekenberghe)

101. Consortium & Association
How to sustain Pharo?
How to structure the community?

103. Consortium Members
Managed by Inria for now
Who: companies, institutions, user groups
Privileged access to the core development team
Influence priorities of the next development
Engineering support time
Job posts
Training/Conferences special prices

105. Pharo User Association
Managed by the Pharo Association
Individuals
Premium (99 €/year)
Normal (40 €/year)
Join and participate!

106. Pharo books
Pharo by example
translated to french, merci!
translated to spanish, gracias!
translated to japanese, ありがとう!
german started
http://pharobyexample.org

107. New books are coming
Deep into Pharo
Pharo for the Enterprise
A glimpse at VM

108. Everybody can help
Reporting bugs
Confirming bugs
Writing tests
Writing examples
Writing comments
Simple contributing fixes
Discussion, feedback

109. May 2008 Bern
July 2009 Bern
October 2009 Lille
November 2009 Buenos Aires
March 2010 Bern
May 2010 Buenos Aires
June 2010 Bern
June 2010 Bruxelles
July 2010 London
September 2010 Barcelona
September 2010 Lille
January 2011 Lille
July 2011 Lille
October 2011 Bruxelles
February 2012 Bern
October 2012 Bern
April 2012 Lille
August 2012 Ghent
October 2012 Perto Madryn
January 2013 Santiago
February 2013 Lille
April 2013 Lille
June 2013 Lille
Open Pharo Sprints

110. To Take Away
Because it is simple and extensible, Pharo is a nice
platform to experiment on
Use it for your own research (language design or
implementation, types, modularity, empirical studies…)
http://www.pharo.org