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Class gnu.rex.Rex 

java.lang.Object
   |
   +----gnu.rex.Rex
public class Rex
extends Object
This is a key class of the package. It allows you to invoke the tow main actions: expression parsing and matching it against a string. The regular expressions supported are a subset of lex plus some extensions: 

  x			the character x.
 "x"			an x, even if x is an operator.
 \x			an x, even if x is an operator.
 [xy]		the character x or y.
 [x-z]		the character x, y or z.
 [^x]		any character but x.
 .			any character but newline.
 ^x			an x at the beginning of a line.
 x$			an x at the end of a line.
 x?			an optional x.
 x*			0 or more instances of x.
 x+			1 or more instances of x.
 x\|y		an x or a y.
 \(x\)		an x matched as a subexpression.
 x{m,n}		m through n occurences of x.
 \n		a back reference, where n is a digit 0 through 9

Method Index

o build(String)
builds an internal representation for a given regular expression and
returns the corresponding reg.expr.
o config_Alternative(String)
determines the string recognized as the alternative symbol
o config_CharClass(String, char)
defines a new class of characters.
There are at least two default classes \W and \S.
o config_GroupBraces(String, String)
determines what sequences stand for the open/close subexpression symbols.
o match(char[], int, int)
tries to match the regular expression in a given array of characters
o printStates()
o toString()

Methods

o build 
 public static Rex build(String regExpr) throws RegExprSyntaxException
builds an internal representation for a given regular expression and
returns the corresponding reg.expr. matcher object.

Parameters:
regExpr - a string determining a valid regular expression
Returns:
a regular expression object to use for reg.expr. matching
Throws: RegExprSyntaxException
if regExpr has unacceptable syntax
o config_Alternative 
 public static final void config_Alternative(String alt)
determines the string recognized as the alternative symbol

Parameters:
alt - the default value is "\|"
o config_GroupBraces 
 public static void config_GroupBraces(String openGroup,
                                       String closeGroup)
determines what sequences stand for the open/close subexpression symbols. Note that the changes made by a call of this method affect all subsequent calls of build().

Parameters:
openGroup - the default value is "\("
closeGroup - the default value is "\)"
o config_CharClass 
 public static boolean config_CharClass(String set,
                                        char name)
defines a new class of characters.
There are at least two default classes \W and \S.
\W stands for the word constituent character class and \S,
which is basically complimentary to \W, defines spaces and delimiters.

Parameters:
set - a sequence of characters to comprise the class.
If it begins with a ^ it is interpreted as "all characters but"
(see [^x-z] above ).
name - a one character name for the class. Only upper case names are supported in this version.
o match 
 public RexResult match(char input[],
                        int offset,
                        int limit)
tries to match the regular expression in a given array of characters

Parameters:
input - input array of characters
offset - the starting offset
limit - the ending offset
Returns:
the set of pairs each representing offset and length of the corresponding subexpression. Only 9 (1 through 9) subexpressions are supported. The pair at 0 element represents the entire matched region.
o printStates 
 public void printStates()
o toString 
 public String toString()
Overrides:
toString in class Object 
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