Package org.apache.lucene.util.automaton

Class BasicAutomata

  • public final class BasicAutomata
extends java.lang.Object
    Construction of basic automata.

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static Automaton makeAnyChar()
      Returns a new (deterministic) automaton that accepts any single codepoint.
      static Automaton makeAnyString()
      Returns a new (deterministic) automaton that accepts all strings.
      static Automaton makeChar​(int c)
      Returns a new (deterministic) automaton that accepts a single codepoint of the given value.
      static Automaton makeCharRange​(int min, int max)
      Returns a new (deterministic) automaton that accepts a single codepoint whose value is in the given interval (including both end points).
      static Automaton makeEmpty()
      Returns a new (deterministic) automaton with the empty language.
      static Automaton makeEmptyString()
      Returns a new (deterministic) automaton that accepts only the empty string.
      static Automaton makeInterval​(int min, int max, int digits)
      Returns a new automaton that accepts strings representing decimal non-negative integers in the given interval.
      static Automaton makeString​(int[] word, int offset, int length)  
      static Automaton makeString​(java.lang.String s)
      Returns a new (deterministic) automaton that accepts the single given string.
      static Automaton makeStringUnion​(java.util.Collection<BytesRef> utf8Strings)
      Returns a new (deterministic and minimal) automaton that accepts the union of the given collection of BytesRefs representing UTF-8 encoded strings.

      • Methods inherited from class java.lang.Object

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

    • Method Detail

      • makeEmpty

        public static Automaton makeEmpty()
        Returns a new (deterministic) automaton with the empty language.

      • makeEmptyString

        public static Automaton makeEmptyString()
        Returns a new (deterministic) automaton that accepts only the empty string.

      • makeAnyString

        public static Automaton makeAnyString()
        Returns a new (deterministic) automaton that accepts all strings.

      • makeAnyChar

        public static Automaton makeAnyChar()
        Returns a new (deterministic) automaton that accepts any single codepoint.

      • makeChar

        public static Automaton makeChar​(int c)
        Returns a new (deterministic) automaton that accepts a single codepoint of the given value.

      • makeCharRange

        public static Automaton makeCharRange​(int min,
                                      int max)
        Returns a new (deterministic) automaton that accepts a single codepoint whose value is in the given interval (including both end points).

      • makeInterval

        public static Automaton makeInterval​(int min,
                                     int max,
                                     int digits)
                              throws java.lang.IllegalArgumentException
        Returns a new automaton that accepts strings representing decimal non-negative integers in the given interval.
        Parameters:
        min - minimal value of interval
        max - maximal value of interval (both end points are included in the interval)
        digits - if >0, use fixed number of digits (strings must be prefixed by 0's to obtain the right length) - otherwise, the number of digits is not fixed
        Throws:
        java.lang.IllegalArgumentException - if min>max or if numbers in the interval cannot be expressed with the given fixed number of digits

      • makeString

        public static Automaton makeString​(java.lang.String s)
        Returns a new (deterministic) automaton that accepts the single given string.

      • makeString

        public static Automaton makeString​(int[] word,
                                   int offset,
                                   int length)

      • makeStringUnion

        public static Automaton makeStringUnion​(java.util.Collection<BytesRef> utf8Strings)
        Returns a new (deterministic and minimal) automaton that accepts the union of the given collection of BytesRefs representing UTF-8 encoded strings.
        Parameters:
        utf8Strings - The input strings, UTF-8 encoded. The collection must be in sorted order.
        Returns:
        An Automaton accepting all input strings. The resulting automaton is codepoint based (full unicode codepoints on transitions).