org.vedantatree.expressionoasis

Class Parser

java.lang.Object

org.vedantatree.expressionoasis.Parser

public final class Parser
extends Object

This parser object parses the expressions, break these in expression tokens and perform lexical analysis on these tokens. All kind of expressions can be parsed like arithmetic, function call, and property accessor etc. By default, it ignores the extra blanks.

Some examples of expression
1). 123 + 124 - 67 * 45 div 90 + (12 + 34 div 67) .
2). principal * pow(( 1 - rate div 100 ), time) .
3). 120 * pow(sin(20) div tan(30), 2) .
4). values[0] + values[1] + values[2] + 120 * 45 div num[1][1] .
5). person.address.city.name + students[0].rollNo .
6). /person/address/city/name + /person/children[name='Ram'] + /person/children[1] .
7). abc=xyz || 1!=2 && 3 >= xyz && xvz <= 30 .

Version:

1.0 Wrapped logger debug/trace calls with checks to see if debugging/tracing is enabled, as they were causing significant performance issues unnecessarily., 1.1

Author:

Mohit Gupta, Parmod Kamboj, Kris Marwood

Constructor Summary

Constructors

Constructor and Description
Parser() Deprecated. seems of no use, since Parser is always created from Compiler with Grammar instance
Parser(Grammar grammar) Constructs the Parser with given DefaultXMLGrammar object

Method Summary

Modifier and Type	Method and Description
static void	main(String[] args)
List<ExpressionToken>	parse(String expression) It parses the given expression string into ExpressionToken objects and returns the list of ExpressionTokens.

Methods inherited from class java.lang.Object

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

Constructor Detail

Parser

public Parser()

Deprecated. seems of no use, since Parser is always created from Compiler with Grammar instance

Constructs the Parser with default DefaultXMLGrammar instance

Parser

public Parser(Grammar grammar)

Constructs the Parser with given DefaultXMLGrammar object

Parameters:

grammar - the grammar using which it parse the expression.

Throws:

IllegalArgumentException - if the grammar is null.

Method Detail

parse

public final List<ExpressionToken> parse(String expression)
                                  throws ExpressionEngineException

It parses the given expression string into ExpressionToken objects and returns the list of ExpressionTokens.

Parameters:

expression - the expression string to parse

Returns:

list of ExpressionToken

Throws:

ExpressionEngineException - if unable to parse

IllegalArgumentException - if the expression is not a qualified string

main

public static void main(String[] args)
                 throws ExpressionEngineException

Throws:

ExpressionEngineException