Package net.sf.saxon.regex

This package contains the code to map XML Schema and XPath regular expressions to a regular expression engine of the underlying Java platform.

Most of the classes implement a regular expression engine derived from Apache's Jakarta project. The code of Jakarta has been modified so that the regular expressions implement the syntax of XSD/XPath regular expressions. There have also been extensive changes for performance reasons

In addition, there are classes to provide direct access to the native JDK regular expression engine. The flags value ";j" may be used to select this engine. The resulting syntax/semantics will not be an exact match to the XPath definition.

Users should not normally need to use these classes directly.

Earlier versions of Saxon included a translator from XPath regular expressions to Java regular expressions, based on that produced by James Clark. This mechanism is no longer used.

Interface Summary

Interface	Description
RegexIterator	This interface defines an iterator that supports the evaluation of xsl:analyze-string.
RegexMatchHandler	Interface defining a call-back action for processing captured groups within a regular expression
RegularExpression	This interface represents a compiled regular expression.

Class Summary

Class	Description
ARegexIterator	Class ARegexIterator - provides an iterator over matched and unmatched substrings.
ARegularExpression	Glue class to interface the Jakarta regex engine to Saxon (The prefix 'A' indicates an Apache regular expression, as distinct from a JDK regular expression).
ATokenIterator	A ATokenIterator is an iterator over the strings that result from tokenizing a string using a regular expression
Capture	Represents a match of a captured subgroup
CaseVariants	This singleton class holds data about the case-variants of Unicode characters.
History	The History object is used to avoid backtracking too far.
JavaRegularExpression	An implementation of RegularExpression that calls the JDK regular expression library directly.
JRegexIterator	Class JRegexIterator - provides an iterator over matched and unmatched substrings.
JTokenIterator	A JTokenIterator is an iterator over the strings that result from tokenizing a string using a regular expression, in this case a regular expression evaluated using the JDK regex engine
OpAtom	A match against a fixed string of any length, within a regular expression
OpBackReference	A back-reference in a regular expression
OpBOL	Beginning of Line (^) in a regular expression
OpCapture	Open paren (captured group) within a regular expression
OpCharClass	A match of a single character in the input against a set of permitted characters
OpChoice	A choice of several branches within a regular expression
OpEndProgram	End of program in a regular expression
OpEOL	End of Line ($) in a regular expression
Operation	Represents an operation or instruction in the regular expression program.
Operation.ForceProgressIterator	The ForceProgressIterator is used to protect against non-termination; specifically, iterators that return an infinite number of zero-length matches.
OpGreedyFixed	Handle a greedy repetition (with possible min and max) where the size of the repeated unit is fixed.
OpNothing	Match empty string within a regular expression
OpReluctantFixed	Handle a reluctant repetition (with possible min and max) where the size of the repeated unit is fixed.
OpRepeat	Handle a repetition (with possible min and max) where the size of the repeated unit is variable.
OpSequence	A sequence of multiple pieces in a regular expression
OpTrace	Operation that wraps a base operation and traces its execution
OpUnambiguousRepeat	Handle a repetition where there is no ambiguity; if the repeated term is matched in the string, then it cannot match anything other than the repeated term.
RECompiler	A regular expression compiler class.
REFlags	Class representing a set of regular expression flags (some combination of i, m, s, x, q).
RegexPrecondition	A precondition that must be true if a regular expression is to match
REMatcher	RE is an efficient, lightweight regular expression evaluator/matcher class.
REMatcher.State
REProgram	A class that holds compiled regular expressions.
UnicodeBlocks	This singleton class provides knowledge of the names and contents of Unicode character blocks, as referenced using the \p{IsXXXXX} construct in a regular expression.

Exception Summary

Exception	Description
RESyntaxException	Exception thrown to indicate a syntax error in a regular expression.