MSV Core 2022.7 · com.sun.msv.verifier.regexp

VGM implementation by using regular expression derivation algorithm.

This implementation bridges a gap between neutral grammar model (com.sun.msv.grammar) and Verifier grammar model (com.sun.msv.verifier).

Performance Analysis

This bridge is tuned for client-side use, where MSV is repeatedly invoked from command line. Particularly,

No preprocessing of grammar is necessary. Abstract grammar model can be directly used. This results in faster schema loading, at the expense of slower validation.
Extensive error recovery and detailed error diagnosis is provided.

Also, this bridge covers full expressiveness of RELAX and TREX.

Algorithm

Those who are interested in the algorithm of this package may want to see the following resources.

regexp.tar.gz: regular expression matching algorithm by Mark Hopkins.
How to validate XML: A brief introduction of the above algorithm by Joe English
TREX implementation: This implementation by James Clark employs the algorithm of Mark Hopkins.

Class Summary

Modifier and Type	Class and Description
public class	AnyElementToken special Token that matchs any element.
public class	AttributeFeeder Feeds AttributeToken to the expression and obtains the residual (content model).
public class	AttributePicker removes all unnecessary expressions and creates an expression that consists of required attributes and choices only.
public class	AttributePruner Creates an expression whose AttributeExp is completely replaced by nullSet.
pack-priv class	AttributeRecoveryToken special AttributeToken that memorizes `AttributeExp` that fails to validate itself.
public class	AttributeRemover Creates an expression whose AttributeExp is completely replaced by epsilon.
public class	AttributeToken represents attribute and its value.
public class	CombinedChildContentExpCreator creates "combined child content expression" and gathers "elements of concern" and its "attribute-pruned" content model.
public class	ComplexAcceptor Accept that is used when more than one pattern can be applicable to the current context.
public abstract class	ComplexAcceptorBaseImpl base implementation of ComplexAcceptor.
public abstract class	ContentModelAcceptor base implementation for SimpleAcceptor and ComplexAcceptor
public class	ContentModelRefExpRemover Non-recursive ReferenceExpRemover with a cache.
public class	ElementsOfConcernCollector Collects "elements of concern".
public class	ElementToken a token that represents an XML element.
public abstract class	ExpressionAcceptor `Acceptor` implementation.
pack-priv class	OptimizationTag this object will be added to Expression.verifierTag to speed up typical validation.
public class	REDocumentDeclaration `DocumentDeclaration` implementation Grammar object can be shared among multiple threads, but this object cannot be shared.
public class	ResidualCalculator computes regular expression derivative.
public class	SimpleAcceptor Acceptor that will be used when only one ElementExp matches the start tag.
public class	StringCareLevelCalculator calculates how character literals should be treated.
pack-priv class	StringRecoveryToken special StringToken that acts as a wild card.
public class	StringToken chunk of string.
public abstract class	Token primitive unit of XML instance.

Package com.sun.msv.verifier.regexp

Performance Analysis

Algorithm

Class Summary