Evaluating Strategies of Sorting, Filtering, and Grouping API Methods

for Code Completion

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Daqing Hou, David M. Pletcher

Clarkson University, Potsdam NY

1Wednesday, September 28, 2011

Evaluating Strategies of Sorting, Filtering, and Grouping API Methods

for Code Completion

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2Wednesday, September 28, 2011

Information Overloading

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• Large APIsex: JDK 1.6, 3,777 classes and interfaces

• Learning barriers [Ko et al. 2004]- design- selection- coordination & use- information & understand

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Evaluating Strategies of Sorting, Filtering, and Grouping API Methods

for Code Completion

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Code Completion as Antidotecurrent

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• In Eclipse, completion proposals sortedalphabetically or by-relevance.

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Evaluating Strategies of Sorting, Filtering, and Grouping API Methods

for Code Completion

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BCC: Better Code Completion

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Code Completion as Antidotenew - 2 ways of sorting

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• type-based sorting

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Code Completion as Antidotenew - 2 ways of sorting

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• use count-based sorting

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Code Completion as Antidotenew - filtering

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1. public, non-API methodsex: javax.swing.JComponent.updateUI()

2. Visible only for limited receiver typesex: JPanel.add(), but not JButton.add()

3. Visible in subclass onlyex: java.awt.Component.paint()

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Code Completion as Antidotenew - grouping

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• Display logically related methods together

ex: add()/getComponent()/remove() for a Container

• Filtering and grouping rules for each API need to be specified only once.

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Evaluating Strategies of Sorting, Filtering, and Grouping API Methods

for Code Completion

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Evaluation Methodology

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• Compare 14 configurations with Eclipse’s by-relevance as baseline in terms of rank reduction. - rank reduction (7)- primer (2)- structuring (5)

• 9 open-source projects

• Metric- rank for an API method- project-wide rank

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Evaluation Result 1: Rank Reduction

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7 configurations ordered by rank reduction!

Best: regular dynamic ranking!

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Evaluation Result 2: Primer7/9 dynamic primers worse than regular dynamic ranking!

adjusted primers mixed results!

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Evaluation Result 3: Structuring

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• Two mechanisms: grouping and static primers.

• Regular dynamic ranking+grouping is the best configuration for grouping.

• 8/9 static primers are better than type+filtering.

• Static primers worse than regular dynamic ranking+grouping, but can still be useful.

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Design Recommendations

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• Regular dynamic ranking and adjusted primers for rank reduction.

• Regular dynamic ranking+grouping for additional benefit of API learning.

• Static primers worse than regular dynamic ranking+grouping, but can still be useful.

• Provide multiple options for developers choose from.

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Conclusion and future work

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• Implemented Code Completion strategies for moving forward needed API methods, hiding non-API public methods, and grouping API methods according to their semantic relatedness.

• Evaluated 14 configurations of these strategies on 9 projects that use AWT/Swing.

• Gave design recommendations.

• Future work includes user studies for features such as grouping, and ways to make primers work.

• Contact me for BCC source code.

17Wednesday, September 28, 2011