com.sun.labs.minion.retrieval.parser
Class Transformer

java.lang.Object
  com.sun.labs.minion.retrieval.parser.Transformer

Direct Known Subclasses:

LuceneTransformer, StrictTransformer, WebTransformer

public abstract class Transformer
extends java.lang.Object

This class transforms the output of JavaCC into a tree of query elements that the query evaluator can understand. It's more than meets the eye.

Constructor Summary

Transformer()

Method Summary

static boolean	isDoubleQuoted(java.lang.String str) Determines if a string is double quoted, that is, it begins and ends with a " character.
static boolean	isQuoted(java.lang.String str) Determines if a string is a quoted string.
static boolean	isSingleQuoted(java.lang.String str) Determines if a string is single quoted, that is, it begins and ends with a ' character.
abstract QueryElement	transformTree(SimpleNode root) Transforms an abstract syntax tree provided by JJTree+JavaCC into a tree of QueryElements that can be used by the query evaluator.
abstract QueryElement	transformTree(SimpleNode root, int defaultOperator) Transforms an abstract syntax tree provided by JJTree+JavaCC into a tree of QueryElements that can be used by the query evaluator.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Transformer

public Transformer()

Method Detail

transformTree

public abstract QueryElement transformTree(SimpleNode root)
                                    throws java.text.ParseException

Transforms an abstract syntax tree provided by JJTree+JavaCC into a tree of QueryElements that can be used by the query evaluator.

Parameters:

root - the root node of the tree returned from the Parser

Returns:

the root node of a tree describing a query

Throws:

java.text.ParseException

transformTree

public abstract QueryElement transformTree(SimpleNode root,
                                           int defaultOperator)
                                    throws java.text.ParseException

Transforms an abstract syntax tree provided by JJTree+JavaCC into a tree of QueryElements that can be used by the query evaluator.

Parameters:

root - the root node of the tree returned from the Parser

defaultOperator - specified the default operator to use when no other operator is provided between terms in the query. Valid values are defined in the Searcher interface

Returns:

the root node of a tree describing a query

Throws:

java.text.ParseException

isQuoted

public static boolean isQuoted(java.lang.String str)

Determines if a string is a quoted string. If it starts and ends with ' or starts and ends with " then it is a quoted string.

Parameters:

str - the string to check

Returns:

true if the string is quoted

isDoubleQuoted

public static boolean isDoubleQuoted(java.lang.String str)

Determines if a string is double quoted, that is, it begins and ends with a " character.

Parameters:

str - the string to check

Returns:

true if the string is double quoted

isSingleQuoted

public static boolean isSingleQuoted(java.lang.String str)

Determines if a string is single quoted, that is, it begins and ends with a ' character.

Parameters:

str - the string to check

Returns:

true if the string is single quoted