org.ceryle.wiki.plugin.query
Class ExpressionParser

java.lang.Object
  org.ceryle.wiki.plugin.query.ExpressionParser

All Implemented Interfaces:

PluginConstants

Direct Known Subclasses:

AssertionProcessor

public class ExpressionParser
extends Object
implements PluginConstants

This is the first line of defense against bad query strings. Parses from the original string form into Terms, Operators and if the user explicitly had parenthesis, sub-Expressions.

Author:

John Volkar (john.volkar at gmail.com), Murray Altheim

Field Summary

Fields inherited from interface org.ceryle.wiki.plugin.util.PluginConstants

ACL, AOP, APOS_ENT, ASTERISK, BCL, BOP, BR, CAPCL, CAPOP, CLATT, COLON, COMMA, DIV_class, DIV_style, DIVCL, DOT, EQ, EQQUO, EQSQUO, FALSE, FORMCL, FORMOP, GET, ICL, INPUTOP, IOP, LABELCL, LABELFOR, LABELOP, LCURL, LICL, LIOP, LPAR, LSBR, MT, NBSP, NL, OLCL, OLOP, P_class, PCL, PLUGCL, PLUGO, POP, POST, QUO, QUOCL, QUOETCL, RCURL, RPAR, RSBR, SEMI, SP, SPAN_class, SPANCL, SPANOP, SQUO, TABLECL, TABLEOP, TDCL, TDOP, THCL, THOP, TRCL, TROP, TRUE, TTCL, TTOP, ULCL, ULOP, UNDER

Constructor Summary

ExpressionParser()

Method Summary

protected List	collapseBracketedTerms(List list) Join back together the bracketed page names.
protected List	explicitExpressions(List list) Create expressions based on use of explicit parentheses in the expression.
protected int	findLastOpen(List list)
protected int	findNextClose(List list, int startIndex)
Expression	parse(String queryString) Parse the string and return one top-level expression which if toString()'d would show the canonical form that the user should have given if his syntax was perfect.
protected List	replaceOperators(List list) Replace string names of operators with Operator instances.
protected void	syntaxCheckBrackets(CharacterIterator iter) Square brackets must exist balance and NOT nest...

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpressionParser

public ExpressionParser()

Method Detail

parse

public Expression parse(String queryString)
                 throws QueryException

Parse the string and return one top-level expression which if toString()'d would show the canonical form that the user should have given if his syntax was perfect.

Parameters:

queryString -

Returns:

the generated Expression

Throws:

QueryException

collapseBracketedTerms

protected List collapseBracketedTerms(List list)

Join back together the bracketed page names.

Parameters:

list -

Returns:

the processed List

replaceOperators

protected List replaceOperators(List list)
                         throws QueryException

Replace string names of operators with Operator instances. If there is unrecognizable text throw a QueryException. Returned list will only have "(", ")", Term and Operator instances in it. The String comparisons are made on intern()'d Strings, so this is relatively fast.

Parameters:

list - the input List

Returns:

the modified List

Throws:

QueryException

explicitExpressions

protected List explicitExpressions(List list)
                            throws QueryException

Create expressions based on use of explicit parentheses in the expression.

Parameters:

list - the input List

Returns:

the modified List

Throws:

QueryException

findLastOpen

protected int findLastOpen(List list)

findNextClose

protected int findNextClose(List list,
                            int startIndex)

syntaxCheckBrackets

protected void syntaxCheckBrackets(CharacterIterator iter)
                            throws QueryException

Square brackets must exist balance and NOT nest...

Parameters:

chars -

Throws:

QueryException