Class Perl5Compiler

java.lang.Object
org.apache.oro.text.regex.Perl5Compiler
All Implemented Interfaces:
PatternCompiler

public final class Perl5Compiler extends Object implements PatternCompiler
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.

Since:
1.0
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  • Field Details

    • __WORSTCASE

      private static final int __WORSTCASE
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    • __NONNULL

      private static final int __NONNULL
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    • __SIMPLE

      private static final int __SIMPLE
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    • __SPSTART

      private static final int __SPSTART
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    • __TRYAGAIN

      private static final int __TRYAGAIN
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    • __CASE_INSENSITIVE

      private static final char __CASE_INSENSITIVE
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    • __GLOBAL

      private static final char __GLOBAL
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    • __KEEP

      private static final char __KEEP
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    • __MULTILINE

      private static final char __MULTILINE
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    • __SINGLELINE

      private static final char __SINGLELINE
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    • __EXTENDED

      private static final char __EXTENDED
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    • __READ_ONLY

      private static final char __READ_ONLY
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    • __HEX_DIGIT

      private static final String __HEX_DIGIT
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    • __input

      private CharStringPointer __input
    • __sawBackreference

      private boolean __sawBackreference
    • __modifierFlags

      private final char[] __modifierFlags
    • __numParentheses

      private int __numParentheses
    • __programSize

      private int __programSize
    • __cost

      private int __cost
    • __program

      private char[] __program
    • __hashPOSIX

      private static final HashMap<String,Character> __hashPOSIX
      Lookup table for POSIX character class names
    • 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.
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    • 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.
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    • 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.
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    • 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.
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    • 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.
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    • 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.
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  • Constructor Details

    • Perl5Compiler

      public Perl5Compiler()
  • Method Details

    • 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.

      Parameters:
      expression - The expression to convert.
      Returns:
      A String containing a Perl5 regular expression corresponding to a literal interpretation of the pattern.
    • 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.

      Parameters:
      expression - Expression
      Returns:
      A String containing a Perl5 regular expression corresponding to a literal interpretation of the pattern.
    • __isSimpleRepetitionOp

      private static boolean __isSimpleRepetitionOp(char ch)
    • __isComplexRepetitionOp

      private static boolean __isComplexRepetitionOp(char[] ch, int offset)
    • __parseRepetition

      private static boolean __parseRepetition(char[] str, int off)
    • __parseHex

      private static int __parseHex(char[] str, int off, int ml, int[] scanned)
    • __parseOctal

      private static int __parseOctal(char[] str, int off, int ml, int[] scanned)
    • __setModifierFlag

      private static void __setModifierFlag(char[] flags, char ch)
    • __emitCode

      private void __emitCode(char code)
    • __emitNode

      private int __emitNode(char operator)
    • __emitArgNode

      private int __emitArgNode(char operator, char arg)
    • __programInsertOperator

      private void __programInsertOperator(char operator, int oper)
    • __programAddTail

      private void __programAddTail(int current, int value)
    • __programAddOperatorTail

      private void __programAddOperatorTail(int current, int value)
    • __getNextChar

      private char __getNextChar()
    • __parseAlternation

      private int __parseAlternation(int[] retFlags) throws MalformedPatternException
      Throws:
      MalformedPatternException
    • __parseAtom

      private int __parseAtom(int[] retFlags) throws MalformedPatternException
      Throws:
      MalformedPatternException
    • __parseUnicodeClass

      private int __parseUnicodeClass() throws MalformedPatternException
      Throws:
      MalformedPatternException
    • __parsePOSIX

      private char __parsePOSIX(boolean[] negFlag)
      Parse POSIX epxression like [:foo:].
      Returns:
      OpCode. return 0 when fail parsing POSIX expression.
    • __parseBranch

      private int __parseBranch(int[] retFlags) throws MalformedPatternException
      Throws:
      MalformedPatternException
    • __parseExpression

      private int __parseExpression(boolean isParenthesized, int[] hintFlags) throws MalformedPatternException
      Throws:
      MalformedPatternException
    • 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.

      Specified by:
      compile in interface PatternCompiler
      Parameters:
      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.
      Returns:
      A Pattern instance constituting the compiled regular expression. This instance will always be a Perl5Pattern and can be reliably casted to a Perl5Pattern.
      Throws:
      MalformedPatternException - If the compiled expression is not a valid Perl5 regular expression.
    • compile

      public Pattern compile(char[] pattern) throws MalformedPatternException
      Same as calling compile(pattern, Perl5Compiler.DEFAULT_MASK);

      Specified by:
      compile in interface PatternCompiler
      Parameters:
      pattern - A regular expression to compile.
      Returns:
      A Pattern instance constituting the compiled regular expression. This instance will always be a Perl5Pattern and can be reliably casted to a Perl5Pattern.
      Throws:
      MalformedPatternException - If the compiled expression is not a valid Perl5 regular expression.
    • compile

      public Pattern compile(String pattern) throws MalformedPatternException
      Same as calling compile(pattern, Perl5Compiler.DEFAULT_MASK);

      Specified by:
      compile in interface PatternCompiler
      Parameters:
      pattern - A regular expression to compile.
      Returns:
      A Pattern instance constituting the compiled regular expression. This instance will always be a Perl5Pattern and can be reliably casted to a Perl5Pattern.
      Throws:
      MalformedPatternException - If the compiled expression is not a valid Perl5 regular expression.
    • 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.

      Specified by:
      compile in interface PatternCompiler
      Parameters:
      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("ˆ\\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.
      Returns:
      A Pattern instance constituting the compiled regular expression. This instance will always be a Perl5Pattern and can be reliably casted to a Perl5Pattern.
      Throws:
      MalformedPatternException - If the compiled expression is not a valid Perl5 regular expression.