XSnippet: Mining For Sample Code

XSnippet: Mining For Sample Code

Naiyana Tansalarak and Kajal Claypool

Presented by: Shan Li CISC864

Topics

Overall of Research Purposes Contributions Approaches

Detail in Approaches

Overall of Research

Purposes: To provide sample codes for new

developers to learn tech. quickly Approaches

Mining sample codes from existing software systems

Overall of Research cont. Steps in Approaches

Range of Queries generalized / specialized? Ranking Heuristics for context-sensitive /

context-independence Such as: constructor function / constructor

function of DOM Mining Algorithms

BFSMINE Alg. , restricts: inside a scope of a method

Extensions to BFSMINE Alg.

Approaches: the Snippet Mining Processes

Figure1: A high-level view of the snippet Mining Process

Approaches cont. The goal of the snippet mining is to mine from a

given code sample repository all code snippets that satisfy a given user query Q,

SelectionAgent pre-selects a set of code model instances cmi on B+ tree index defined on all types declared or referred to in the code sample repository.

The MiningAgent invokes the BFSMINE algorithm for every code model instance Ccmi

Approaches cont. BFSMINE algorithm traverses a code model

instance and produces as output a set of paths P that represent the final code snippets returned to the user.

On completion of the BFSMINE phase, the MiningAgent passes the collection of the paths P, to the PruningAgent.

Approaches cont. Queries

The query retun all snippets s,

containing codes that instantiate a type tq:

(1) all codes that instantiate tq:

(2) instantiation of tq is dependent of the code context, i.e. via a static method

The following example

Approaches cont.

Approaches cont. Queries

A type-based instantiation query tq is instantiated from any type from the

context CT(m) T (s) the lexically visible types in the

code snippet s and CT (m) denotes the type context of the method

CT (m) : all set of inherited types, visible types in a scope of method, all types for local fields

Approaches cont.

Approaches cont. Queries

Parent-based in instantiation query s denotes a snippet, CP (s) the parent

context of the snippet, CP (m) the parent context of the method m.

CP (m): The parent context of a method m, denoted as CP (m), is a set containing the superclass extended by its containing source class C, as well as all interfaces implemented by its containing source class C.

Approaches cont.

Approaches cont. Source Code Model

A graphic representation of the structure of source codes. Nodes: a type node, an object node, a method node

Edges: inheritance, implement, composite, method, assignment or parameter edge.

Approaches cont. BFSMINE Algorithm

Given a user query , The goal of the BFSMINE algorithm is to determine for all such instances nq, types and eventually code segments that instantiate the node nq and hence the query type tq. Domain(nq) = {tq}

Approaches cont.

Approaches cont.

Extension-BFSMIN

Approaches cont.

Extension-BFSMIN

Approaches cont.

Personal Comments Strengths

User defined queries Results from a context-independent retrieval

to various degrees of context-sensitive retrieval

BFSMIN Algorithm based on a graph that represents a source code model allows mining across method boundaries

Ranking heuristic (length, frequency, context ) for providing best-fit code snippets

Multiple sample codes with the same query context-independent retrieval (length / frequency ) context-sensitive retrieval (context)

Personal Comments Potential weakness

Results Is it possible to provide semantic ranking ? Why? Probably, the return code snippets do not

have logic among them, just only a chunk of codes Validation approaches

To prove that snippet codes is helpful for developers, authors use group test. Two groups with the same condition except that one uses snippet codes, other do not.

Limited ?