1. Wissenstransfer 2.0:
Liest du noch, oder programmierst du schon?
The knowledge transfer company

2. • Project Lead of Eclipse Code Recommenders
• Eclipse Committer since 2010
• Plug-in Developer for 10 years (Eclipse 2.1)
• Member of the Eclipse Architecture Council
• Co-Lead of Java User Group Darmstadt
• Speaker at JUGs, EclipseCon, JAX, JavaOne…
• PhD in Computer Science
• CEO of Codetrails
!
• Passion to improve developers day-to-day work
with intelligent and practical tools - mostly using
Data Mining on Big (Software Engineering) Data.
About Me
2
@MarcelBruch
+MarcelBruch

3. Codetrails at a Glance
• The company behind Eclipse Code Recommenders
• Eclipse RCP Experts & Consultants
• Software Tool Developers
• Data Mining Specialists
• Research Spin-off Darmstadt University of Technology
3
supported by

4. About Eclipse Code Recommenders
4
2006 2009 2011
2012 2013 2014
Research
begins
CR
published
CR goes
Eclipse
CR 1.0
Part of IDE CR 2.0
CR 2.1

5. Awards & Traction
5
2012
• >3.000.000 downloads
Top 20
• Talks at 50+ Democamps, Eclipse Days,
and Java User Groups all over Europe.
• Talks at 10+ intl. and
local conferences.
• articles every 4 months,
• lots of general coverage

6. PROBLEM

7. Problem #1: Knowledge Drain
7

8. Problem #1: Knowledge Drain
8

9. Problem #1: Knowledge Drain
9
Software

10. Problem #2: Continuous Learning
10

11. A typical developer day
11
Comprehend Task
3 %
Handling Interruptions
20 %
Navigate Code
14 %
Study Code
19 %
Searching Web
12 %
Reading Docs
6 %
Write Code
27 %
51% of their time, developers invest in searching
and understanding code

12. How we search
12

13. What developers look for
13
Question + Answer + Code Example = ✓

14. A typical developer day
14
Comprehend Task
3 %
Handling Interruptions
20 %
Navigate Code
14 %
Study Code
19 %
Searching Web
12 %
Reading Docs
6 %
Write Code
27 %
Even when writing code
we search…

15. If we don’t google…
15

16. 1 of 387 ?

17. 17
Code Completion
Frequency : 100 completions / day
Duration (⌀) : 27 seconds / completion
Sum : 45 minutes / day
9% of their time developers spent
searching in their code completion

18. Problem
18
Comprehend Task
3 %
Handling Interruptions
20 %
Searching Code
12 %
Navigate Code
14 %
Reading Code
19 %
Reading Docs
6 %
Edit Code
27 %

19. Problem
19
Comprehend Task
3 %
Handling Interruptions
20 %
Searching Code
12 %
Navigate Code
14 %
Reading Code
19 %
Reading Docs
6 %
Edit Code
27 %
• 51% of their time, developers spent searching the
web and existing code for help
• In addition, even when programming, they spent
9% searching in their code completion
• In total, 60% is about finding the right information
to solve a programming task

20. SOLUTION
„Leveraging the power of the crowds“

21. Behind every answered question…
21

22. … there is some code
22

23. Use the code
23

24. INTELLIGENT CODE COMPLETION
„Other developers frequently bought used the following methods…“

25. @Override!
protected Control createDialogArea(final Composite parent) {!
Composite container = (Composite) super.createDialogArea(parent);!
!
swtTextWidget = new Text(container, SWT.BORDER);!
swtTextWidget.|!
return container;!
}
Code Completion…
What does the developer need, i.e., which methods
should the code completion present to the user?
25

26. All 164 Methods of Text ?

27. Intelligent Code Completion
What your team really needs to know…
27

28. Snippet Completion (1)
28

29. HOW IT WORKS
„Finding the hidden gems in your code“

30. class Example extends Page {!
Text t;!
!
@Override!
void createContents() {!
t = new Text();!
t.setText(..);!
...!
}!
...!
}
in:Page.performOk()
Text.<init>()
Text.getText()
Text.setFont()
...
Text.setText()
… … … … … … …
0 0 0 …
30
1 1 1
From code to models...
in:Page.createContents()

31. 31
class Example extends Page {!
Text t;!
...!
!
@Override!
void performOk() {!
t.getText();!
...!
}!
!
}
in:Page.performOk()
Text.<init>()
Text.getText()
Text.setFont()
...
Text.setText()
1 0 1 1
1 1
0 0
0 0 0 0
… … … … … …
…
…
…
From code to models...
in:Page.createContents()

32. 32
class MyPage extends Page {!
!
Text t;!
@Override!
void createContents() {!
t = new Text();!
t.|<^space>!
}!
...!
}
1 …1 ?? ?0
From models to recommendations...
in:Page.performOk()
Text.<init>()
Text.getText()
Text.setFont()
...
Text.setText()
in:Page.createContents()

33. 33
1 …1 ?? ?0
in:Page.performOk()
Text.<init>()
Text.getText()
Text.setFont()
...
Text.setText()
01 10 0 …
1 10 0 0 0
… … … … … …
…
…
1
0 1 1 1 0 …1
01 00 0 …1
⅔ ⅓ 0
From models to recommendations...
in:Page.createContents()

34. CALL-CHAIN COMPLETION
“Welcome to the jungle...”

35. public class MyView extends ViewPart {!
!
public void updateMessage(final String newMessage) {!
!
// How do I get an instance of IStatusLineManager?!
final IStatusLineManager manager = |!
!
}
How to obtain an instance of...
There is no trivial solution.
Again, what should code completion return?
35

36. What we need...
36
ViewPart
IViewSite
IAc-onBars
IStatusLineManager
getStatusLineManager()
getAc-onbars()
getViewSite()
public void updateMessage(final String newMessage) {!
!
// How do I get an instance of !
!
final IStatusLineManager manager = !
this!
.getViewSite()!
.getActionBars()!
.getStatusLineManager();!
!
manager.setMessage(newMessage);!
}

37. SUBWORDS COMPLETION
“BecausePureCamelCaseMatching****s!”

38. Use speaking names...?
38

39. When letters become just guidelines...
39I Like?
Source: http://vimeo.com/19369928

40. EXTENDING API DOCUMENTATION
“Developers who bought overwrote this method typically also overwrote...”

41. In good documentation we trust...
41
good
/**!
* Rollsback the transaction if any and clears different lists to!
* start with an empty resource again.!
* Note that the super.doUnload is not called because that clears!
* the list resulting in all kinds of undesirable inverseremoves.!
*/!
@Override!
protected void doUnload() {!
super.doUnload();!
}!
!
No? Are you sure?

42. Generating high-quality API documentation
42
/**!
* The number of questions.!
*/!
private int numberOfQuestions;!
!
!
/**!
* Sets the number of questions.!
* !
* @param numberOfQuestions the number of questions!
* @throws IllegalArgumentException the illegal argument exception!
*/!
public void setNumberOfQuestions(int numberOfQuestions) !
throws IllegalArgumentException {!
if (numberOfQuestions < 0) {!
throw new IllegalArgumentException("numberOfQuestions < 0");!
}!
this.numberOfQuestions = numberOfQuestions;!
}

43. What people say about JAutodoc...
43
User: Anonymous Rating: 9 2009-08-02 11:32:37
Wow exactly what I needed!
User: Anonymous Rating: 9 2009-02-13 19:58:32
Thank you... this plugin rocks!
User: Anonymous Rating: 9 2009-02-13 19:58:32
Works perfectly. Smarter than I expected!
WTH? What did you expect?!

44. How Recommenders is coming to rescue...
44

45. What documentation would you expect when
subclassing Dialog?
45
package org.eclipse.recommenders.examples.demo;!
!
import org.eclipse.jface.*;!
!
public class MyDialog extends Dialog {!
!
protected MyDialog(final IShellProvider parentShell) {!
super(parentShell);!
} !
}!
!

46. What Javadoc gives you...
46
A dialog is a specialized window used for narrow-
focused communication with the user.
!
Dialogs are usually modal. Consequently, it is
generally bad practice to open a dialog without a
parent. A modal dialog without a parent is not
prevented from disappearing behind the application's
other windows, making it very confusing for the user.
!
If there is more than one modal dialog is open the
second one should be parented off of the shell of the
first one otherwise it is possible that the OS will cus to
the first dialog potentially blocking the UI.
But what are the
hot-spots of Dialog?
org.eclipse.jface.dialogs.Dialog

47. What code completion offers...
47
Which of the 56 methods
should we override?

48. Recommending method overrides...
48
!
public class MyDialog extends Dialog {!
!

49. Recommending self-calls
49
public class MyWizard extends Wizard {!
!
! @Override!
public void addPages() {!
!
};

50. Mining for subclassing patterns
50
!
public class MyViewerSorter extends ViewerComparator {

51. Mined example code snippets…
51
!
public class MyDialog extends Dialog {!
!
@Override!
protected Control createDialogArea(Composite parent) {!
!

52. SNIPMATCH
„Stop searching Stackoverflow for code snippets“

53. Why do you use code templates?
53

54. Safe time typing
54
<ctrl+space>
<ctrl+space>
{
<ctrl+space>
<ctrl+space>
}

55. Learning from snippets
55

56. Eclipse Java Templates
56
42x Java Templates.
35x SWT Templates.

57. Learning from snippets
57

58. The rise of code snippet repositories
58
and many more...

59. Snipmatch
59
Recom
m
enders 2.1

60. AND IF THERE IS NO CODE TO ANALYZE?
„From code analysis to crowd sourcing“

61. Being for Software Developers
How 39 million click events make your IDE a smarter place

62. 62

63. 63

64. The amazon success factors
64

65. 65
How about applying the very same
principles to software development?

66. So, instead of using the web browser…
66

68. 68
!
!
!
Disclaimer
!
Data sharing is
involved!
!
Not Eclipse anymore!

69. Crowdsourced Code Completion
Developers that bought used a StringBuilder, typically…
69

70. A fairly trivial example…
70

71. Instead saying…
71

72. What if we‘d just count calls...?
72
Codetrails Connect Community Edition,
Install from http://www.codetrails.com/connect

73. !
void ctor() {
!
List l = new A…
}
Crowdsourced Constructor Completion
73
What is the mostly likely completion a
developer looks for in this particular situation ?

74. 74
1 out of 302

75. !
void ctor() {
!
List l = new A…
}
Use (costly) subtype checks
75
Codetrails Completion Tweaks for Eclipse,
Install from http://download.codetrails.com/updates/connect/

76. Crowdsourcing constructor completions...?
76
It learns from you. From the very 1st moment.
Codetrails Connect Community Edition,
Install from http://download.codetrails.com/updates/connect/

77. public class MyDialog extends Dialog {
!
|
!
!
Crowdsourcing override completions...?
77

78. !
void quickfix() {
!
List l = new A
}
How about fixing quick-fix?
78
Not fixed yet. But could be easily - when you start sharing your knowledge…

79. 39.000.000 clicks for a smarter IDE
79
Read more (October 2013)
http://www.codetrails.com/blog/powered-33-million-code-completions-codetrails-connect-12
Method Overrides
1.579.303
Constructor Calls
8.915.540
Method Calls
38.254.438
48.749.281
Bootstrapped with
30++ GB Java Bytecode.
Powered by Maven Central
and EclipseSource Yoxos.

80. 56.424 crowdsourced completion events
80
org.eclipse.*
11 %org.apache.*
4 %
com.google.*
9 %
com.vaadin.*
5 %
com.codetrails.*
3 %
others
14 %
javax.*
3 %
java.[n]io.*
6 %
java.util.*
25 %
java.lang.*
21 %
From December 22 to March 12

81. Trend: Events sent by the community
81
Visit the Codetrails Connect live dashboard:
http://download.codetrails.com/connect/dashboard/

82. How well does it work?
82
What do you expect?

83. How well does it work?
83
Numberofproposalsmade
1
2
3
4
5
6
7
Position in code completion window
-1 0 1 2 3 4 5 6
993
475
304
214
189
123
1.094
833
327 238
197 114 87
145 56 40 38
96 61 23 22 21
77 52 19 21 20 10
963 591 373 243 285 151 157
Hit
Miss
not found

84. Successfully concluded sessions
84
Codetrails
78,8
JDT
67,9
JDT standalone vs. Codetrails
Developers find what they need 11% more often with smart code completion.
Number of documentation lookups saved in 3 months: 3.000!

85. What get’s shared?
85

86. What is shared?
86
{!
„type“: „StringBuilder“,!
„completion“: „append(String)“!
}

87. Sharing Preferences
87

88. Still scared of crowdsourcing?
88
Do you also suffer from Anatidaephobia?
„Big Brother is watching you“
http://anniemachon.ch/annie_machon/2013/11/cryptofestival-london-30th-november.html

89. 89
ANATIDAEPHOBIA IS THE FEAR
THAT SOMEWHERE IN THE WORLD,
THERE IS A DUCK WATCHING YOU.

90. 90
https://vaadin.com/blog/-/blogs/crowdsourcing-vaadin-with-codetrails-connect

91. 91
Snippets going social
5 0

92. Enriching Javadoc
92
Eclipse Code Recommenders Livedoc 0.8 Incubator
Install from http://eclipse.org/recommenders/incubators

93. Javadocs with mined snippets
93http://download.codetrails.com/livedoc/published/latest/org/eclipse/jface/org.eclipse.jface/3.8.102/

94. 94
Breaking News:!
Words carry meaning!
As leading scientists found out, words....
Rethinking Recommendation
for Code Completion

95. A simple observation
95
You wouldn‘t expect a call to #dispose()
in #createSomething(), right?

96. What you expect is...
96

97. How many words do you have for ‟create” ?
97

98. So, it works for #createSomething too!
98

99. Almost no difference!
99
Precision
0
25
50
75
100
Recall
0 10 20 30 40 50 60 70 80 90 100
Classic
Verbs
Interpolated Precision Recall Curves over 136.761 samples on JRE

100. What get‘s shared?
100
{!
„method“: „create“!
„type“: „Composite“,!
„completion“: „setLayout(...)“!
}

101. Let‘s back up here for a second!
101

102. We get (almost) language agnostic!
102

103. Read More
103

104. Installation
104

105. WRAP UP
„Closing notes“

106. All that only happens if you share…
106

107. 107
Yes, there is a duck somewhere.

108. 108But it probably doesn’t care what you are doing.

109. THANK YOU
@MarcelBruch
+MarcelBruch