com.ibm.tivoli.maximo.report.expr

Class ExprParser

java.lang.Object

com.ibm.tivoli.maximo.report.expr.ExprParser

public class ExprParser
extends java.lang.Object

An Expression Parser parses an expression, such as 'FIELDA+DateDiff(Now(), Later())+10' into a Parse Tree of Nodes that can be navigated and validated. Parsers are NOT THREAD SAFE so a new parser must be created for parsing instance. The purpose of the Exprssion Parser is NOT to validate expression, but rather to provide a tokenized parse tree of the elements that make up the expression. Other tasks can later validate parsed elements if they want, looking for specific element types, etc. Using a parser is a simple as using.

 Node root = ExprParser.parse("fielda * 12 + fieldb");
 

Once you have root Node, you can the iterator over the nodes, or create a "Visitor" and have a visitor visit each node in the expression.

Author:

sls

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	ExprParser.ParserHelper
static class	ExprParser.State

Constructor Summary

Constructors

Constructor and Description
ExprParser()

Method Summary

Modifier and Type	Method and Description
void	addChild(Node parent, Node child)
static Node	parse(java.lang.String expression) Given an expression, return a parse tree of the expression.
static Node	parse(java.lang.String expression, ExprParser.ParserHelper parserHelper) Given an expression, return a parse tree of the expression.
static Node	parse(java.lang.String expression, com.ibm.icu.util.ULocale locale) Given an expression, return a parse tree of the expression.
static Node	parse(java.lang.String expression, com.ibm.icu.util.ULocale locale, ExprParser.ParserHelper parserHelper) Given an expression, return a parse tree of the expression.
Node	parseExpression(java.lang.String str, com.ibm.icu.util.ULocale locale, ExprParser.ParserHelper helper) Parses an expression using a given decimal separator.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExprParser

public ExprParser()

Method Detail

parseExpression

public Node parseExpression(java.lang.String str,
                            com.ibm.icu.util.ULocale locale,
                            ExprParser.ParserHelper helper)
                     throws MXException

Parses an expression using a given decimal separator. Because expressions can contain literal numbers we need to know what a numeric decimal separator looks like so that we can effectively parse out number literals as number types.

Parameters:

str -

decimalSeparator -

Returns:

Throws:

MXException

addChild

public void addChild(Node parent,
                     Node child)

parse

public static Node parse(java.lang.String expression)
                  throws MXException

Given an expression, return a parse tree of the expression. Will assume a "." as the decimal separator

Parameters:

expression -

Returns:

Throws:

MXException

parse

public static Node parse(java.lang.String expression,
                         com.ibm.icu.util.ULocale locale)
                  throws MXException

Given an expression, return a parse tree of the expression. Will use the decimal separator for the given locale

Parameters:

expression -

Returns:

Throws:

MXException

parse

public static Node parse(java.lang.String expression,
                         com.ibm.icu.util.ULocale locale,
                         ExprParser.ParserHelper parserHelper)
                  throws MXException

Given an expression, return a parse tree of the expression. Will use the decimal separator for the given locale

Parameters:

expression -

Returns:

Throws:

MXException

parse

public static Node parse(java.lang.String expression,
                         ExprParser.ParserHelper parserHelper)
                  throws MXException

Given an expression, return a parse tree of the expression. Will assume a "." as the decimal separator

Parameters:

expression -

Returns:

Throws:

MXException