程序包 org.apache.oro.text.awk

类 AwkCompiler

java.lang.Object
org.apache.oro.text.awk.AwkCompiler
所有已实现的接口:
PatternCompiler
public final class AwkCompiler extends Object implements PatternCompiler
The AwkCompiler class is used to create compiled regular expressions conforming to the Awk regular expression syntax. It generates AwkPattern instances upon compilation to be used in conjunction with an AwkMatcher instance. AwkMatcher finds true leftmost-longest matches, so you must take care with how you formulate your regular expression to avoid matching more than you really want.

The supported regular expression syntax is a superset of traditional AWK, but NOT to be confused with GNU AWK or other AWK variants. Additionally, this AWK implementation is DFA-based and only supports 8-bit ASCII. Consequently, these classes can perform very fast pattern matches in most cases.

This is the traditional Awk syntax that is supported:

  • Alternatives separated by |
  • Quantified atoms
    *
    Match 0 or more times.
    +
    Match 1 or more times.
    ?
    Match 0 or 1 times.
  • Atoms
    • regular expression within parentheses
    • a . matches everything including newline
    • a ^ is a null token matching the beginning of a string but has no relation to newlines (and is only valid at the beginning of a regex; this differs from traditional awk for the sake of efficiency in Java).
    • a $ is a null token matching the end of a string but has no relation to newlines (and is only valid at the end of a regex; this differs from traditional awk for the sake of efficiency in Java).
    • Character classes (e.g., [abcd]) and ranges (e.g. [a-z])
      • Special backslashed characters work within a character class
    • Special backslashed characters
      \b
      backspace
      \n
      newline
      \r
      carriage return
      \t
      tab
      \f
      formfeed
      \xnn
      hexadecimal representation of character
      \nn or \nnn
      octal representation of character
      Any other backslashed character matches itself

This is the extended syntax that is supported:

  • Quantified atoms
    {n,m}
    Match at least n but not more than m times.
    {n,}
    Match at least n times.
    {n}
    Match exactly n times.
  • Atoms
    • Special backslashed characters
      \d
      digit [0-9]
      \D
      non-digit [^0-9]
      \w
      word character [0-9a-z_A-Z]
      \W
      a non-word character [^0-9a-z_A-Z]
      \s
      a whitespace character [ \t\n\r\f]
      \S
      a non-whitespace character [^ \t\n\r\f]
      \cD
      matches the corresponding control character
      \0
      matches null character
从以下版本开始:
1.0
版本:
@version@
另请参阅:

  • 字段概要

    字段
    修饰符和类型
    字段
    说明
    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.
    static final int
    DEFAULT_MASK
    The default mask for the compile methods.
    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.

  • 构造器概要

    构造器
    构造器
    说明
    AwkCompiler()
     

  • 方法概要

    修饰符和类型
    方法
    说明
    Pattern
    compile(char[] pattern)
    Same as calling compile(pattern, AwkCompiler.DEFAULT_MASK);
    Pattern
    compile(char[] pattern, int options)
    Compiles an Awk regular expression into an AwkPattern instance that can be used by an AwkMatcher object to perform pattern matching.
    Pattern
    compile(String pattern)
    Same as calling compile(pattern, AwkCompiler.DEFAULT_MASK);
    Pattern
    compile(String pattern, int options)
    Compiles an Awk regular expression into an AwkPattern instance that can be used by an AwkMatcher object to perform pattern matching.

    从类继承的方法 java.lang.Object

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

  • 字段详细资料

    • DEFAULT_MASK

      public static final int DEFAULT_MASK
      The default mask for the compile methods. It is equal to 0 and indicates no special options are active.
      另请参阅:

    • 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.
      另请参阅:

    • 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 . metacharacters. When this mask is used, the . metacharacter will not match newlines. The default behavior is for . to match newlines.
      另请参阅:

  • 构造器详细资料

    • AwkCompiler

      public AwkCompiler()

  • 方法详细资料

    • compile

      public Pattern compile(char[] pattern, int options) throws MalformedPatternException
      Compiles an Awk regular expression into an AwkPattern instance that can be used by an AwkMatcher object to perform pattern matching.

      指定者:
      compile 在接口中 PatternCompiler
      参数:
      pattern - An Awk regular expression to compile.
      options - A set of flags giving the compiler instructions on how to treat the regular expression. Currently the only meaningful flag is AwkCompiler.CASE_INSENSITIVE_MASK.
      返回:
      A Pattern instance constituting the compiled regular expression. This instance will always be an AwkPattern and can be reliably be casted to an AwkPattern.
      抛出:
      MalformedPatternException - If the compiled expression is not a valid Awk regular expression.

    • compile

      public Pattern compile(String pattern, int options) throws MalformedPatternException
      Compiles an Awk regular expression into an AwkPattern instance that can be used by an AwkMatcher object to perform pattern matching.

      指定者:
      compile 在接口中 PatternCompiler
      参数:
      pattern - An Awk regular expression to compile.
      options - A set of flags giving the compiler instructions on how to treat the regular expression. Currently the only meaningful flag is AwkCompiler.CASE_INSENSITIVE_MASK.
      返回:
      A Pattern instance constituting the compiled regular expression. This instance will always be an AwkPattern and can be reliably be casted to an AwkPattern.
      抛出:
      MalformedPatternException - If the compiled expression is not a valid Awk regular expression.

    • compile

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

      指定者:
      compile 在接口中 PatternCompiler
      参数:
      pattern - A regular expression to compile.
      返回:
      A Pattern instance constituting the compiled regular expression. This instance will always be an AwkPattern and can be reliably be casted to an AwkPattern.
      抛出:
      MalformedPatternException - If the compiled expression is not a valid Awk regular expression.

    • compile

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

      指定者:
      compile 在接口中 PatternCompiler
      参数:
      pattern - A regular expression to compile.
      返回:
      A Pattern instance constituting the compiled regular expression. This instance will always be an AwkPattern and can be reliably be casted to an AwkPattern.
      抛出:
      MalformedPatternException - If the compiled expression is not a valid Awk regular expression.