gnu.regexp
Class RESyntax

java.lang.Object
  gnu.regexp.RESyntax

All Implemented Interfaces:

Serializable

public class RESyntax
extends Object
implements Serializable

An RESyntax specifies the way a regular expression will be compiled. This class provides a number of predefined useful constants for emulating popular regular expression syntaxes. Additionally the user may construct his or her own syntax, using any combination of the syntax bit constants. The syntax is an optional argument to any of the matching methods on class RE.

Author:

Wes Biggs

See Also:

Serialized Form

Field Summary

static int	RE_BACKSLASH_ESCAPE_IN_LISTS Syntax bit.
static int	RE_BK_PLUS_QM Syntax bit.
static int	RE_CHAR_CLASS_ESC_IN_LISTS Syntax bit.
static int	RE_CHAR_CLASS_ESCAPES Syntax bit.
static int	RE_CHAR_CLASSES Syntax bit.
static int	RE_COMMENTS Syntax bit.
static int	RE_CONTEXT_INDEP_ANCHORS Syntax bit.
static int	RE_CONTEXT_INDEP_OPS Syntax bit.
static int	RE_CONTEXT_INVALID_OPS Syntax bit.
static int	RE_DOT_NEWLINE Syntax bit.
static int	RE_DOT_NOT_NULL Syntax bit.
static int	RE_HAT_LISTS_NOT_NEWLINE Syntax bit.
static int	RE_INTERVALS Syntax bit.
static int	RE_LIMITED_OPS Syntax bit.
static int	RE_LOOKAHEAD Syntax bit.
static int	RE_NEWLINE_ALT Syntax bit.
static int	RE_NO_BK_BRACES Syntax bit.
static int	RE_NO_BK_PARENS Syntax bit.
static int	RE_NO_BK_REFS Syntax bit.
static int	RE_NO_BK_VBAR Syntax bit.
static int	RE_NO_EMPTY_RANGES Syntax bit.
static int	RE_PURE_GROUPING Syntax bit.
static int	RE_STINGY_OPS Syntax bit.
static int	RE_STRING_ANCHORS Syntax bit.
static RESyntax	RE_SYNTAX_AWK Predefined syntax.
static RESyntax	RE_SYNTAX_ED Predefined syntax.
static RESyntax	RE_SYNTAX_EGREP Predefined syntax.
static RESyntax	RE_SYNTAX_EMACS Predefined syntax.
static RESyntax	RE_SYNTAX_GREP Predefined syntax.
static RESyntax	RE_SYNTAX_PERL4 Predefined syntax.
static RESyntax	RE_SYNTAX_PERL4_S Predefined syntax.
static RESyntax	RE_SYNTAX_PERL5 Predefined syntax.
static RESyntax	RE_SYNTAX_PERL5_S Predefined syntax.
static RESyntax	RE_SYNTAX_POSIX_AWK Predefined syntax.
static RESyntax	RE_SYNTAX_POSIX_BASIC Predefined syntax.
static RESyntax	RE_SYNTAX_POSIX_EGREP Predefined syntax.
static RESyntax	RE_SYNTAX_POSIX_EXTENDED Predefined syntax.
static RESyntax	RE_SYNTAX_POSIX_MINIMAL_BASIC Predefined syntax.
static RESyntax	RE_SYNTAX_POSIX_MINIMAL_EXTENDED Predefined syntax.
static RESyntax	RE_SYNTAX_SED Predefined syntax.
static int	RE_UNMATCHED_RIGHT_PAREN_ORD Syntax bit.

Constructor Summary

RESyntax()
Construct a new syntax object with all bits turned off.

RESyntax(RESyntax other)
Construct a new syntax object with all bits set the same as the other syntax.

Method Summary

RESyntax	clear(int index) Clear a given bit in this syntax.
boolean	get(int index) Check if a given bit is set in this syntax.
String	getLineSeparator() Returns the currently active line separator string.
RESyntax	makeFinal() Called internally when constructing predefined syntaxes so their interpretation cannot vary.
RESyntax	set(int index) Set a given bit in this syntax.
RESyntax	setLineSeparator(String aSeparator) Changes the line separator string for regular expressions created using this RESyntax.

Methods inherited from class java.lang.Object

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

Field Detail

RE_BACKSLASH_ESCAPE_IN_LISTS

public static final int RE_BACKSLASH_ESCAPE_IN_LISTS

Syntax bit.

Backslash is an escape character in lists.

See Also:

Constant Field Values

RE_BK_PLUS_QM

public static final int RE_BK_PLUS_QM

Syntax bit.

Use \? instead of ? and \+ instead of +.

See Also:

Constant Field Values

RE_CHAR_CLASSES

public static final int RE_CHAR_CLASSES

Syntax bit.

POSIX character classes ([:...:]) in lists are allowed.

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Constant Field Values

RE_CONTEXT_INDEP_ANCHORS

public static final int RE_CONTEXT_INDEP_ANCHORS

Syntax bit.

^ and $ are special everywhere. Not implemented.

See Also:

Constant Field Values

RE_CONTEXT_INDEP_OPS

public static final int RE_CONTEXT_INDEP_OPS

Syntax bit.

Repetition operators are only special in valid positions. Not implemented.

See Also:

Constant Field Values

RE_CONTEXT_INVALID_OPS

public static final int RE_CONTEXT_INVALID_OPS

Syntax bit.

Repetition and alternation operators are invalid at start and end of pattern and other places. Not implemented.

See Also:

Constant Field Values

RE_DOT_NEWLINE

public static final int RE_DOT_NEWLINE

Syntax bit.

Match-any-character operator (.) matches a newline.

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Constant Field Values

RE_DOT_NOT_NULL

public static final int RE_DOT_NOT_NULL

Syntax bit.

Match-any-character operator (.) does not match a null.

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Constant Field Values

RE_INTERVALS

public static final int RE_INTERVALS

Syntax bit.

Intervals ({x}, {x,}, {x,y}) are allowed.

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Constant Field Values

RE_LIMITED_OPS

public static final int RE_LIMITED_OPS

Syntax bit.

No alternation (|), match one-or-more (+), or match zero-or-one (?) operators.

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Constant Field Values

RE_NEWLINE_ALT

public static final int RE_NEWLINE_ALT

Syntax bit. Newline is an alternation operator.

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Constant Field Values

RE_NO_BK_BRACES

public static final int RE_NO_BK_BRACES

Syntax bit.

Intervals use { } instead of \{ \}

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Constant Field Values

RE_NO_BK_PARENS

public static final int RE_NO_BK_PARENS

Syntax bit.

Grouping uses ( ) instead of \( \).

See Also:

Constant Field Values

RE_NO_BK_REFS

public static final int RE_NO_BK_REFS

Syntax bit.

Backreferences not allowed.

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Constant Field Values

RE_NO_BK_VBAR

public static final int RE_NO_BK_VBAR

Syntax bit.

Alternation uses | instead of \|

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Constant Field Values

RE_NO_EMPTY_RANGES

public static final int RE_NO_EMPTY_RANGES

Syntax bit. Not implemented.

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Constant Field Values

RE_UNMATCHED_RIGHT_PAREN_ORD

public static final int RE_UNMATCHED_RIGHT_PAREN_ORD

Syntax bit.

An unmatched right parenthesis (')' or '\)', depending on RE_NO_BK_PARENS) will throw an exception when compiling.

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Constant Field Values

RE_HAT_LISTS_NOT_NEWLINE

public static final int RE_HAT_LISTS_NOT_NEWLINE

Syntax bit. Not implemented.

See Also:

Constant Field Values

RE_STINGY_OPS

public static final int RE_STINGY_OPS

Syntax bit.

Stingy matching is allowed (+?, *?, ??, {x,y}?).

See Also:

Constant Field Values

RE_CHAR_CLASS_ESCAPES

public static final int RE_CHAR_CLASS_ESCAPES

Syntax bit.

Allow character class escapes (\d, \D, \s, \S, \w, \W).

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Constant Field Values

RE_PURE_GROUPING

public static final int RE_PURE_GROUPING

Syntax bit.

Allow use of (?:xxx) grouping (subexpression is not saved).

See Also:

Constant Field Values

RE_LOOKAHEAD

public static final int RE_LOOKAHEAD

Syntax bit. Not implemented.

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Constant Field Values

RE_STRING_ANCHORS

public static final int RE_STRING_ANCHORS

Syntax bit.

Allow beginning- and end-of-string anchors (\A, \Z).

See Also:

Constant Field Values

RE_COMMENTS

public static final int RE_COMMENTS

Syntax bit.

Allow embedded comments, (#comment), as in Perl5.

See Also:

Constant Field Values

RE_CHAR_CLASS_ESC_IN_LISTS

public static final int RE_CHAR_CLASS_ESC_IN_LISTS

Syntax bit. Allow character class escapes within lists, as in Perl5.

See Also:

Constant Field Values

RE_SYNTAX_AWK

public static final RESyntax RE_SYNTAX_AWK

Predefined syntax. Emulates regular expression support in the awk utility.

RE_SYNTAX_ED

public static final RESyntax RE_SYNTAX_ED

Predefined syntax. Emulates regular expression support in the ed utility.

RE_SYNTAX_EGREP

public static final RESyntax RE_SYNTAX_EGREP

Predefined syntax. Emulates regular expression support in the egrep utility.

RE_SYNTAX_EMACS

public static final RESyntax RE_SYNTAX_EMACS

Predefined syntax. Emulates regular expression support in the GNU Emacs editor.

RE_SYNTAX_GREP

public static final RESyntax RE_SYNTAX_GREP

Predefined syntax. Emulates regular expression support in the grep utility.

RE_SYNTAX_POSIX_AWK

public static final RESyntax RE_SYNTAX_POSIX_AWK

Predefined syntax. Emulates regular expression support in the POSIX awk specification.

RE_SYNTAX_POSIX_BASIC

public static final RESyntax RE_SYNTAX_POSIX_BASIC

Predefined syntax. Emulates POSIX basic regular expression support.

RE_SYNTAX_POSIX_EGREP

public static final RESyntax RE_SYNTAX_POSIX_EGREP

Predefined syntax. Emulates regular expression support in the POSIX egrep specification.

RE_SYNTAX_POSIX_EXTENDED

public static final RESyntax RE_SYNTAX_POSIX_EXTENDED

Predefined syntax. Emulates POSIX extended regular expression support.

RE_SYNTAX_POSIX_MINIMAL_BASIC

public static final RESyntax RE_SYNTAX_POSIX_MINIMAL_BASIC

Predefined syntax. Emulates POSIX basic minimal regular expressions.

RE_SYNTAX_POSIX_MINIMAL_EXTENDED

public static final RESyntax RE_SYNTAX_POSIX_MINIMAL_EXTENDED

Predefined syntax. Emulates POSIX extended minimal regular expressions.

RE_SYNTAX_SED

public static final RESyntax RE_SYNTAX_SED

Predefined syntax. Emulates regular expression support in the sed utility.

RE_SYNTAX_PERL4

public static final RESyntax RE_SYNTAX_PERL4

Predefined syntax. Emulates regular expression support in Larry Wall's perl, version 4,

RE_SYNTAX_PERL4_S

public static final RESyntax RE_SYNTAX_PERL4_S

Predefined syntax. Emulates regular expression support in Larry Wall's perl, version 4, using single line mode (/s modifier).

RE_SYNTAX_PERL5

public static final RESyntax RE_SYNTAX_PERL5

Predefined syntax. Emulates regular expression support in Larry Wall's perl, version 5.

RE_SYNTAX_PERL5_S

public static final RESyntax RE_SYNTAX_PERL5_S

Predefined syntax. Emulates regular expression support in Larry Wall's perl, version 5, using single line mode (/s modifier).

Constructor Detail

RESyntax

public RESyntax()

Construct a new syntax object with all bits turned off. This is equivalent to RE_SYNTAX_EMACS.

RESyntax

public RESyntax(RESyntax other)

Construct a new syntax object with all bits set the same as the other syntax.

Method Detail

makeFinal

public RESyntax makeFinal()

Called internally when constructing predefined syntaxes so their interpretation cannot vary. Conceivably useful for your syntaxes as well. Causes IllegalAccessError to be thrown if any attempt to modify the syntax is made.

Returns:

this object for convenient chaining

get

public boolean get(int index)

Check if a given bit is set in this syntax.

set

public RESyntax set(int index)

Set a given bit in this syntax.

Parameters:

index - the constant (RESyntax.RE_xxx) bit to set.

Returns:

a reference to this object for easy chaining.

clear

public RESyntax clear(int index)

Clear a given bit in this syntax.

Parameters:

index - the constant (RESyntax.RE_xxx) bit to clear.

Returns:

a reference to this object for easy chaining.

setLineSeparator

public RESyntax setLineSeparator(String aSeparator)

Changes the line separator string for regular expressions created using this RESyntax. The default separator is the value returned by the system property "line.separator", which should be correct when reading platform-specific files from a filesystem. However, many programs may collect input from sources where the line separator is differently specified (for example, in the applet environment, the text box widget interprets line breaks as single-character newlines, regardless of the host platform. Note that setting the line separator to a character or characters that have specific meaning within the current syntax can cause unexpected chronosynclastic infundibula.

Returns:

this object for convenient chaining

getLineSeparator

public String getLineSeparator()

Returns the currently active line separator string. The default is the platform-dependent system property "line.separator".