Package net.sf.saxon.regex

Class REProgram

java.lang.Object

net.sf.saxon.regex.REProgram

public class REProgram
extends Object

A class that holds compiled regular expressions.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	backtrackingLimit
protected int	fixedLength
protected REFlags	flags
protected IntPredicateProxy	initialCharClass
protected int	maxParens
protected int	minimumLength
protected Operation	operation
protected static final int	OPT_HASBACKREFS
protected static final int	OPT_HASBOL
protected int	optimizationFlags
protected List<RegexPrecondition>	preconditions
protected UnicodeString	prefix

Constructor Summary

Constructors

Constructor	Description
REProgram(Operation operation, int parens, REFlags flags)	Constructs a program object from a character array

Method Summary

Modifier and Type	Method	Description
int	getBacktrackingLimit()
UnicodeString	getPrefix()	Returns a copy of the prefix of current regular expression program in a character array.
boolean	isNullable()	Ask whether the regular expression is known statically to match a zero length string
void	setBacktrackingLimit(int limit)

Methods inherited from class java.lang.Object

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

Field Details

OPT_HASBACKREFS

protected static final int OPT_HASBACKREFS

See Also:

• Constant Field Values

OPT_HASBOL

protected static final int OPT_HASBOL

See Also:

• Constant Field Values

operation

protected Operation operation

flags

protected REFlags flags

prefix

protected UnicodeString prefix

initialCharClass

protected IntPredicateProxy initialCharClass

preconditions

protected List<RegexPrecondition> preconditions

minimumLength

protected int minimumLength

fixedLength

protected int fixedLength

optimizationFlags

protected int optimizationFlags

maxParens

protected int maxParens

backtrackingLimit

protected int backtrackingLimit

Constructor Details

REProgram

public REProgram(Operation operation,
 int parens,
 REFlags flags)

Constructs a program object from a character array

Parameters:

operation - Array with RE opcode instructions in it. The "next"

parens - Count of parens in the program pointers within the operations must already have been converted to absolute offsets.

flags - the regular expression flags

Method Details

setBacktrackingLimit

public void setBacktrackingLimit(int limit)

getBacktrackingLimit

public int getBacktrackingLimit()

isNullable

public boolean isNullable()

Ask whether the regular expression is known statically to match a zero length string

Returns:

true if the regex is known statically to match a zero length string. If the result is true, then there is definitely a match; if the result is false, then it is not known statically whether there is a match (this arises when the expression contains back-references).

getPrefix

public UnicodeString getPrefix()

Returns a copy of the prefix of current regular expression program in a character array. If there is no prefix, or there is no program compiled yet, getPrefix will return null.

Returns:

A copy of the prefix of current compiled RE program