Comment Extractor

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Comment Extractor

• Ethan Chan
• Tianqiu Tem Wang
• Juliana Wong

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Introduction (1)

• What do high level software tools provide?
• abstract level understanding
• specific knowledge
• focus
• After using these tools, programmers eventually
  have to touch source code

Abstract Level
Text Level
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Introduction (2)

• Comment
• explanatory text embedded in program source
• helps human readers understand program source
  code
• the most useful thing at code level

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Motivation (1)

• Comments are localized

Expression of interest
Expression declaration
Comments associated with expression
The same expression used elsewhere

• Comments relating to the expression are found
  only in one place

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Motivation (2)

• Searching for comments
• is a tedious job
• interrupts original work flow

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Motivation (3)

• Sometimes Expression of interest is far away

Possibly a gap of a lot of files!
Expression of interest
Expression Declaration
Comments associated with Expression
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Motivation (4)

• Examples
• Grep
• too many incorrect results
• Javadoc
• format must be specific
• needs to know belonging class
• More in DEMO later on

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Claim

• Programmers shouldnt
• stop the workflow
• do any extra work to find comments.
• Need a tool
• deals with these problems
• extracts comments automatically.

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Solution

• Comment Extractor
• A plug-in for JEdit (an open source java editor)
  
• Extracts comments from 4 types of CO
• Returns comments by Intelli-Selection
• users selection
• cursors location

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What the icons mean
Variable comment
Type comment
Java predefined type comment
Function comment
No comment
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DEMO Introduction to the GUI
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DEMO
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DEMO Complex process finding comments from
Inherited Classes

• Need to knowwhich classhas isInt()scomment

Type
isInt()
isReal()
BasicType
PointerType
.
isInt()
isReal()
isInt()
isReal()
IntType
BooleanType
isInt()
isReal()
isInt()
isReal()
.
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DEMO Finding out
the usual way

• Where is m?
• 170 lines up, we find its declaration
• Where is Machine class?
• 1 out of 61 files, we find its declaration
• Where is method emitLoad?
• 200 lines down, we find two overloaded
  declarations
• Which emitLoad method is correct?
• Need to know what parameter (sto, tmp) types are!
• Give up?

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DEMO Finding out
the JavaDoc way

• Where is m?
• 170 lines up, we find its declaration
• Open JavaDoc on Machine class
• Find emitLoad documentation
• Need to know what parameter (sto, tmp) types are!
• Not all comments are JavaDoc style, so are not
  seen!

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DEMO Finding out
the grep way

• Assuming there are few uses of the text
  emitLoad, where is emitLoad?
• Need to weed out emitLoad declarations
• Much faster, only because not repeated
  declaration
• Still need to know which overloaded method
• (still need to find out sto and tmp!)
• Still need to open files and read comments
• Hard to go back to original position if not
  created in separate process

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DEMO Finding out
the Comment Extractor way
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Limitations

• This tool wont be helpful if
• No comments
• Bad comments
• Comments not associated with a CO
• a plugin currently only for JEdit
• works only for Java

While loop
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Lessons Learned (1)

• Didnt have CE to develop CE
• difficult to understand JEdits massive source
  code
• Unintentional benefits
• i.e. warping files

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Lessons Learned (2)

• Modular design allowed easy integration of
  unanticipated changes
• User Interaction (GUI)
• Functionality

Comment Extractor
JEdit
Comment Hunter
Location Searcher
GUI
JEdit plugin interface
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Any comments? (no pun intended)Well help you
extract it!
Comment Extractor