org.apache.oro.text.regex
Class Perl5Compiler
java.lang.Object
org.apache.oro.text.regex.Perl5Compiler
- PatternCompiler
public final class Perl5Compiler
extends java.lang.Object
The Perl5Compiler class is used to create compiled regular expressions
conforming to the Perl5 regular expression syntax. It generates
Perl5Pattern instances upon compilation to be used in conjunction
with a Perl5Matcher instance. Please see the user's guide for more
information about Perl5 regular expressions.
Perl5Compiler and Perl5Matcher are designed with the intent that
you use a separate instance of each per thread to avoid the overhead
of both synchronization and concurrent access (e.g., a match that takes
a long time in one thread will block the progress of another thread with
a shorter match). If you want to use a single instance of each
in a concurrent program, you must appropriately protect access to
the instances with critical sections. If you want to share Perl5Pattern
instances between concurrently executing instances of Perl5Matcher, you
must compile the patterns with
READ_ONLY_MASK
.
static int | CASE_INSENSITIVE_MASK - A mask passed as an option to the
compile methods
to indicate a compiled regular expression should be case insensitive.
|
static int | DEFAULT_MASK - The default mask for the
compile methods.
|
static int | EXTENDED_MASK - A mask passed as an option to the
compile methods
to indicate a compiled regular expression should be treated as a Perl5
extended pattern (i.e., a pattern using the /x modifier).
|
static int | MULTILINE_MASK - A mask passed as an option to the
compile methods
to indicate a compiled regular expression should treat input as having
multiple lines.
|
static int | READ_ONLY_MASK - A mask passed as an option to the
compile methods
to indicate that the resulting Perl5Pattern should be treated as a
read only data structure by Perl5Matcher, making it safe to share
a single Perl5Pattern instance among multiple threads without needing
synchronization.
|
static int | SINGLELINE_MASK - A mask passed as an option to the
compile methods
to indicate a compiled regular expression should treat input as being
a single line.
|
Pattern | compile(String pattern) - Same as calling compile(pattern, Perl5Compiler.DEFAULT_MASK);
|
Pattern | compile(String pattern, int options) - Compiles a Perl5 regular expression into a Perl5Pattern instance that
can be used by a Perl5Matcher object to perform pattern matching.
|
Pattern | compile(char[] pattern) - Same as calling compile(pattern, Perl5Compiler.DEFAULT_MASK);
|
Pattern | compile(char[] pattern, int options) - Compiles a Perl5 regular expression into a Perl5Pattern instance that
can be used by a Perl5Matcher object to perform pattern matching.
|
static String | quotemeta(String expression) - Given a character string, returns a Perl5 expression that interprets
each character of the original string literally.
|
static String | quotemeta(char[] expression) - Given a character string, returns a Perl5 expression that interprets
each character of the original string literally.
|
CASE_INSENSITIVE_MASK
public static final int CASE_INSENSITIVE_MASK
A mask passed as an option to the compile
methods
to indicate a compiled regular expression should be case insensitive.
DEFAULT_MASK
public static final int DEFAULT_MASK
The default mask for the compile
methods.
It is equal to 0.
The default behavior is for a regular expression to be case sensitive
and to not specify if it is multiline or singleline. When MULITLINE_MASK
and SINGLINE_MASK are not defined, the ^, $, and .
metacharacters are
interpreted according to the value of isMultiline() in Perl5Matcher.
The default behavior of Perl5Matcher is to treat the Perl5Pattern
as though MULTILINE_MASK were enabled. If isMultiline() returns false,
then the pattern is treated as though SINGLINE_MASK were set. However,
compiling a pattern with the MULTILINE_MASK or SINGLELINE_MASK masks
will ALWAYS override whatever behavior is specified by the setMultiline()
in Perl5Matcher.
EXTENDED_MASK
public static final int EXTENDED_MASK
A mask passed as an option to the compile
methods
to indicate a compiled regular expression should be treated as a Perl5
extended pattern (i.e., a pattern using the /x modifier). This
option tells the compiler to ignore whitespace that is not backslashed or
within a character class. It also tells the compiler to treat the
# character as a metacharacter introducing a comment as in
Perl. In other words, the # character will comment out any
text in the regular expression between it and the next newline.
The intent of this option is to allow you to divide your patterns
into more readable parts. It is provided to maintain compatibility
with Perl5 regular expressions, although it will not often
make sense to use it in Java.
MULTILINE_MASK
public static final int MULTILINE_MASK
A mask passed as an option to the compile
methods
to indicate a compiled regular expression should treat input as having
multiple lines. This option affects the interpretation of
the ^ and $ metacharacters. When this mask is used,
the ^ metacharacter matches at the beginning of every line,
and the $ metacharacter matches at the end of every line.
Additionally the . metacharacter will not match newlines when
an expression is compiled with MULTILINE_MASK , which is its
default behavior.
READ_ONLY_MASK
public static final int READ_ONLY_MASK
A mask passed as an option to the compile
methods
to indicate that the resulting Perl5Pattern should be treated as a
read only data structure by Perl5Matcher, making it safe to share
a single Perl5Pattern instance among multiple threads without needing
synchronization. Without this option, Perl5Matcher reserves the right
to store heuristic or other information in Perl5Pattern that might
accelerate future matches. When you use this option, Perl5Matcher will
not store or modify any information in a Perl5Pattern. Use this option
when you want to share a Perl5Pattern instance among multiple threads
using different Perl5Matcher instances.
SINGLELINE_MASK
public static final int SINGLELINE_MASK
A mask passed as an option to the compile
methods
to indicate a compiled regular expression should treat input as being
a single line. This option affects the interpretation of
the ^ and $ metacharacters. When this mask is used,
the ^ metacharacter matches at the beginning of the input,
and the $ metacharacter matches at the end of the input.
The ^ and $ metacharacters will not match at the beginning
and end of lines occurring between the begnning and end of the input.
Additionally, the . metacharacter will match newlines when
an expression is compiled with SINGLELINE_MASK , unlike its
default behavior.
compile
public Pattern compile(String pattern)
throws MalformedPatternException
Same as calling
compile(pattern, Perl5Compiler.DEFAULT_MASK);
- compile in interface PatternCompiler
pattern
- A regular expression to compile.
- A Pattern instance constituting the compiled regular expression.
This instance will always be a Perl5Pattern and can be reliably
casted to a Perl5Pattern.
compile
public Pattern compile(String pattern,
int options)
throws MalformedPatternException
Compiles a Perl5 regular expression into a Perl5Pattern instance that
can be used by a Perl5Matcher object to perform pattern matching.
Please see the user's guide for more information about Perl5 regular
expressions.
- compile in interface PatternCompiler
pattern
- A Perl5 regular expression to compile.options
- A set of flags giving the compiler instructions on
how to treat the regular expression. The flags
are a logical OR of any number of the five MASK
constants. For example:
regex =
compiler.compile("^\\w+\\d+$",
Perl5Compiler.CASE_INSENSITIVE_MASK |
Perl5Compiler.MULTILINE_MASK);
This says to compile the pattern so that it treats
input as consisting of multiple lines and to perform
matches in a case insensitive manner.
- A Pattern instance constituting the compiled regular expression.
This instance will always be a Perl5Pattern and can be reliably
casted to a Perl5Pattern.
compile
public Pattern compile(char[] pattern)
throws MalformedPatternException
Same as calling
compile(pattern, Perl5Compiler.DEFAULT_MASK);
- compile in interface PatternCompiler
pattern
- A regular expression to compile.
- A Pattern instance constituting the compiled regular expression.
This instance will always be a Perl5Pattern and can be reliably
casted to a Perl5Pattern.
compile
public Pattern compile(char[] pattern,
int options)
throws MalformedPatternException
Compiles a Perl5 regular expression into a Perl5Pattern instance that
can be used by a Perl5Matcher object to perform pattern matching.
Please see the user's guide for more information about Perl5 regular
expressions.
- compile in interface PatternCompiler
pattern
- A Perl5 regular expression to compile.options
- A set of flags giving the compiler instructions on
how to treat the regular expression. The flags
are a logical OR of any number of the five MASK
constants. For example:
regex =
compiler.compile(pattern, Perl5Compiler.
CASE_INSENSITIVE_MASK |
Perl5Compiler.MULTILINE_MASK);
This says to compile the pattern so that it treats
input as consisting of multiple lines and to perform
matches in a case insensitive manner.
- A Pattern instance constituting the compiled regular expression.
This instance will always be a Perl5Pattern and can be reliably
casted to a Perl5Pattern.
quotemeta
public static final String quotemeta(String expression)
Given a character string, returns a Perl5 expression that interprets
each character of the original string literally. In other words, all
special metacharacters are quoted/escaped. This method is useful for
converting user input meant for literal interpretation into a safe
regular expression representing the literal input.
In effect, this method is the analog of the Perl5 quotemeta() builtin
method.
- A String containing a Perl5 regular expression corresponding to
a literal interpretation of the pattern.
quotemeta
public static final String quotemeta(char[] expression)
Given a character string, returns a Perl5 expression that interprets
each character of the original string literally. In other words, all
special metacharacters are quoted/escaped. This method is useful for
converting user input meant for literal interpretation into a safe
regular expression representing the literal input.
In effect, this method is the analog of the Perl5 quotemeta() builtin
method.
expression
- The expression to convert.
- A String containing a Perl5 regular expression corresponding to
a literal interpretation of the pattern.
Copyright B) 2000-2003 Apache Software Foundation. All Rights Reserved.