eu.slipo.athenarc.triplegeo.expression

Class SimpleExpr

java.lang.Object

eu.slipo.athenarc.triplegeo.expression.SimpleExpr

All Implemented Interfaces:

Expr

public class SimpleExpr
extends java.lang.Object
implements Expr

Handles a simple logical expression consisting of an identifier, a comparison operator and a literal (string or numeric).

Version:

2.0

Author:

Kostas Patroumpas

Field Summary

Fields

Modifier and Type	Field and Description
private TokenType	comp
private java.lang.String	identifier
private java.lang.String	literal
private Token	op

Constructor Summary

Constructors

Constructor and Description
SimpleExpr(TokenStream stream) Constructor of the class.

Method Summary

Modifier and Type	Method and Description
boolean	evaluate(java.util.Map<java.lang.String,java.lang.String> data) Evaluates the expression against the given input data.
private boolean	like(java.lang.String val, java.lang.String expr) Evaluates an expression involving the LIKE operator.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

identifier

private final java.lang.String identifier

literal

private final java.lang.String literal

op

private Token op

comp

private TokenType comp

Constructor Detail

SimpleExpr

public SimpleExpr(TokenStream stream)
           throws java.text.ParseException

Constructor of the class.

Parameters:

stream - Input stream of tokens

Throws:

java.text.ParseException

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

evaluate

public boolean evaluate(java.util.Map<java.lang.String,java.lang.String> data)

Description copied from interface: Expr

Evaluates the expression against the given input data.

Specified by:

evaluate in interface Expr

Parameters:

data - A data record containing the attribute names (key) and their values.

Returns:

like

private boolean like(java.lang.String val,
                     java.lang.String expr)

Evaluates an expression involving the LIKE operator.

Parameters:

val - The input value to check.

expr - The expression including wild characters like %, ?, etc. as in SQL.

Returns:

True if the input value matches with the expression; otherwise, False.