uk.ac.sheffield.jast.valid

Class UnorderedRule

java.lang.Object

uk.ac.sheffield.jast.valid.GrammarRule

uk.ac.sheffield.jast.valid.CompoundRule

uk.ac.sheffield.jast.valid.UnorderedRule

public class UnorderedRule
extends CompoundRule

UnorderedRule is a kind of CompoundRule for matching a set of patterns. An UnorderedRule contains several other ElementRules as its rule children. These rules will be attempted, in some order, on a list of Elements, which are the immediate children of some parent Element, until each of the rules succeeds exactly once (by default), or at most once (if the optional flag is set). If all the rules eventually succeed in some order, this UnorderedRule will succeed.

An UnorderedRule is created for the XSD complex type specifier xs:all. The optional flag is also set if the multiplicity attribute xs:minOccurs is set to zero.

Version:

2.5

Author:

Anthony J H Simons

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	optional A flag indicating whether the children rules are optional.

Fields inherited from class uk.ac.sheffield.jast.valid.CompoundRule

textFilter

Fields inherited from class uk.ac.sheffield.jast.valid.GrammarRule

identifier, parent

Constructor Summary

Constructors

Constructor and Description
UnorderedRule() Creates an UnorderedRule, whose rule children are patterns to match in any order, exactly once.
UnorderedRule(boolean optional) Creates an UnorderedRule, whose rule children are patterns to match in any order, at most once.

Method Summary

Modifier and Type	Method and Description
boolean	accept(Element node) Reports whether this UnorderedRule accepts an Element with an unordered child pattern.
void	addChildRule(GrammarRule rule) Adds another child GrammarRule to this UnordreredRule.
private boolean	matchAllChildren(Element node) The matching algorithm for an UnorderedRule.
private GrammarRule	matchAnyUnused(Element node, java.util.List<GrammarRule> unusedRules) The auxiliary algorithm seeking to match any so-far unused GrammarRule.
void	setOptional(boolean optional) Sets the optional flag of this UnorderedRule.
java.lang.String	toString() Returns a pretty representation of this UnorderedRule.

Methods inherited from class uk.ac.sheffield.jast.valid.CompoundRule

getRuleChildren, hasNoText, matchChildRule, toString

Methods inherited from class uk.ac.sheffield.jast.valid.GrammarRule

clearError, getChildIndex, getIdentifier, isAttributeRule, isElementRule, isNestingRule, restrict, setChildIndex, setError, setParent, validate

Methods inherited from class java.lang.Object

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

Field Detail

optional

private boolean optional

A flag indicating whether the children rules are optional. If so, they may match zero or one time; otherwise exactly one time.

Constructor Detail

UnorderedRule

public UnorderedRule()

Creates an UnorderedRule, whose rule children are patterns to match in any order, exactly once. The identifier of an UnorderedRule is the symbol "ALL".

UnorderedRule

public UnorderedRule(boolean optional)

Creates an UnorderedRule, whose rule children are patterns to match in any order, at most once. The identifier of an UnorderedRule is the symbol "ALL".

Parameters:

optional - true, to allow

Method Detail

matchAllChildren

private boolean matchAllChildren(Element node)

The matching algorithm for an UnorderedRule. In some arbitrary order, every child rule of this UnorderedRule must eventually match some subsequence of the Element's children. Returns true if all the rule children eventually match exactly once (or at most once, if the optional flag is set). If unused rules remain, returns false, unless the optional flag is set to true.

Parameters:

node - an Element.

Returns:

true, if UnorderedRule matches the Element's children.

matchAnyUnused

private GrammarRule matchAnyUnused(Element node,
                                   java.util.List<GrammarRule> unusedRules)

The auxiliary algorithm seeking to match any so-far unused GrammarRule.

Parameters:

node - an Element.

unusedRules - a list of so-far unused GrammarRules.

Returns:

the rule that matched, or null.

accept

public boolean accept(Element node)

Reports whether this UnorderedRule accepts an Element with an unordered child pattern. Attempts to match the rule children of this UnorderedRule against the corresponding Element children of the node, starting at the next unmatched child. If all the rules match in some order against the next node children, returns true; otherwise returns false, unless the rule is optional.

Overrides:

accept in class GrammarRule

Parameters:

node - the parent Element.

Returns:

true if this UnorderedRule matches the next children.

addChildRule

public void addChildRule(GrammarRule rule)

Adds another child GrammarRule to this UnordreredRule. The child rule may only be an ElementRule; and other kinds of rule are ignored.

Overrides:

addChildRule in class CompoundRule

Parameters:

rule - the child rule to add.

setOptional

public void setOptional(boolean optional)

Sets the optional flag of this UnorderedRule. When set to true, this rule will match each of its rule children at most once; otherwise it will match each rule child exactly once.

Parameters:

optional - true, to enable optional matching.

toString

public java.lang.String toString()

Returns a pretty representation of this UnorderedRule. Surrounds a list of rule children, separated by commas, in set braces.

Overrides:

toString in class java.lang.Object