Package net.sf.saxon.regex

Class RECompiler

java.lang.Object

net.sf.saxon.regex.RECompiler

public class RECompiler
extends java.lang.Object

A regular expression compiler class. This class compiles a pattern string into a regular expression program interpretable by the RE evaluator class. The 'recompile' command line tool uses this compiler to pre-compile regular expressions for use with RE. For a description of the syntax accepted by RECompiler and what you can do with regular expressions, see the documentation for the RE matcher class.

See Also:

REMatcher

Constructor Summary

Constructors

Constructor	Description
RECompiler()	Constructor.

Method Summary

Modifier and Type	Method	Description
REProgram	compile(UnicodeString pattern)	Compiles a regular expression pattern into a program runnable by the pattern matcher class 'RE'.
java.util.List<java.lang.String>	getWarnings()	On completion of compilation, get any warnings that were generated
static CharacterClass	makeComplement(CharacterClass p1)	Make the complement of an IntPredicate (matches if p1 does not match)
static CharacterClass	makeDifference(CharacterClass p1, CharacterClass p2)	Make the difference of two IntPredicates (matches if p1 matches and p2 does not match)
static CharacterClass	makeUnion(CharacterClass p1, CharacterClass p2)	Make the union of two IntPredicates (matches if p1 matches or p2 matches)
static boolean	noAmbiguity(Operation op0, Operation op1, boolean caseBlind, boolean reluctant)	Determine that there is no ambiguity between two branches, that is, if one of them matches then the other cannot possibly match.
void	setFlags(REFlags flags)	Set the regular expression flags to be used

Methods inherited from class java.lang.Object

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

Constructor Detail

RECompiler

public RECompiler()

Constructor. Creates (initially empty) storage for a regular expression program.

Method Detail

setFlags

public void setFlags(REFlags flags)

Set the regular expression flags to be used

Parameters:

flags - the regular expression flags

getWarnings

public java.util.List<java.lang.String> getWarnings()

On completion of compilation, get any warnings that were generated

Returns:

the list of warning messages

makeUnion

public static CharacterClass makeUnion(CharacterClass p1,
                                       CharacterClass p2)

Make the union of two IntPredicates (matches if p1 matches or p2 matches)

Parameters:

p1 - the first

p2 - the second

Returns:

the result

makeDifference

public static CharacterClass makeDifference(CharacterClass p1,
                                            CharacterClass p2)

Make the difference of two IntPredicates (matches if p1 matches and p2 does not match)

Parameters:

p1 - the first

p2 - the second

Returns:

the result

makeComplement

public static CharacterClass makeComplement(CharacterClass p1)

Make the complement of an IntPredicate (matches if p1 does not match)

Parameters:

p1 - the operand

Returns:

the result

compile

public REProgram compile(UnicodeString pattern)
                  throws RESyntaxException

Compiles a regular expression pattern into a program runnable by the pattern matcher class 'RE'.

Parameters:

pattern - Regular expression pattern to compile (see RECompiler class for details).

Returns:

A compiled regular expression program.

Throws:

RESyntaxException - Thrown if the regular expression has invalid syntax.

See Also:

RECompiler, REMatcher

noAmbiguity

public static boolean noAmbiguity(Operation op0,
                                  Operation op1,
                                  boolean caseBlind,
                                  boolean reluctant)

Determine that there is no ambiguity between two branches, that is, if one of them matches then the other cannot possibly match. (This is for optimization, so it does not have to detect all cases; but if it returns true, then the result must be dependable.)

Parameters:

op0 - the first branch

op1 - the second branch

caseBlind - true if the "i" flag is in force

reluctant - true if the first branch is a repeat branch with a reluctant quantifier

Returns:

true if it can be established that there is no input sequence that will match both instructions