Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: CRAQL: A Composable Language for Querying Source Code   This paper describes the design and implementation of CRAQL (Composable
Repository Analysis and Query Language), a new query language for source code.
The growth of source code mining and its applications suggest the need for a
query language that can fully utilize and correlate across the unique structure
and metadata of parsed source code.
  CRAQL is built on an underlying abstraction analogous to the underpinnings of
SQL, but aimed at parsed source code. Thus, while SQL queries' inputs and
outputs are sets of tuples, CRAQL queries' inputs and outputs are sets of
abstract syntax trees (ASTs). This abstraction makes CRAQL queries composable
(the output of one query can become the input to another) and improves the
power of the language by allowing for querying of the tree structure and
metadata, as well as raw text. Furthermore, the abstraction enables
tree-specific language optimizations and allows CRAQL to be easily applied to
any language that is parsable into ASTs. These attributes, along with a
familiar syntax similar to SQL, allow complex queries to be expressed in a
compact, straightforward manner. Questions such as "find the longest series of
statements without any loops," "find methods that are never called," "find
getters (0-parameter methods with a single statement that returns a member
variable)," or "find the percentage of variables declared at the top of a
block" all translate to simple, understandable queries in CRAQL.
  In this paper we describe the language, its features and capabilities. We
compare CRAQL to other languages for querying source code and find that it has
potential advantages in clarity and compactness. We discuss the features and
optimizations added to support searching parse tree collections effectively and
efficiently. Finally, we summarize the application of the language to millions
of Java source files, the details of which are in a companion paper.

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The categories of this paper are: eess
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ph
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The categories of this paper are: q-alg
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The categories of this paper are: hep-ex
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The categories of this paper are: physics
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The categories of this paper are: hep-th
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The categories of this paper are: stat
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The categories of this paper are: nlin
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The categories of this paper are: math
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The categories of this paper are: plasm-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: math-ph