eu.slipo.athenarc.triplegeo.expression

Class ExprResolver

java.lang.Object

eu.slipo.athenarc.triplegeo.expression.ExprResolver

public class ExprResolver
extends java.lang.Object

Resolves the user-specified logical expression and identifies its constituent sub-expressions and logical operators.

Version:

2.0

Author:

Kostas Patroumpas

Field Summary

Fields

Modifier and Type	Field and Description
private static java.util.regex.Pattern	TOKENS

Constructor Summary

Constructors

Constructor and Description
ExprResolver() Constructor of the class.

Method Summary

Modifier and Type	Method and Description
Expr	parse(TokenStream stream) Parses a tokenized logical expression.
TokenStream	tokenize(java.lang.String input) Tokenizes an input logical expression.

Methods inherited from class java.lang.Object

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

Field Detail

TOKENS

private static final java.util.regex.Pattern TOKENS

Constructor Detail

ExprResolver

public ExprResolver()

Constructor of the class.

Method Detail

tokenize

public TokenStream tokenize(java.lang.String input)
                     throws java.text.ParseException

Tokenizes an input logical expression.

Parameters:

input - The input logical expression. Boolean operators include AND, OR, but NOT is not allowed.

Returns:

A tokenized expression that has recognized logical operators and su-expressions (specified in parentheses).

Throws:

java.text.ParseException - Thrown in case that parsing of input expression has failed.

parse

public Expr parse(TokenStream stream)
           throws java.text.ParseException

Parses a tokenized logical expression.

Parameters:

stream - The input composed as a list of recognized tokens, possibly including logical operators (AND, OR).

Returns:

The parsed expression that recognizes sub-expressions and logical operators.

Throws:

java.text.ParseException - Thrown in case that parsing of input expression has failed.