Package cc.mallet.types

Class Alphabet

  • All Implemented Interfaces:
    java.io.Serializable
    Direct Known Subclasses:
    LabelAlphabet
    public class Alphabet
extends java.lang.Object
implements java.io.Serializable
    A mapping between integers and objects where the mapping in each direction is efficient. Integers are assigned consecutively, starting at zero, as objects are added to the Alphabet. Objects can not be deleted from the Alphabet and thus the integers are never reused.

    The most common use of an alphabet is as a dictionary of feature names associated with a FeatureVector in an Instance. In a simple document classification usage, each unique word in a document would be a unique entry in the Alphabet with a unique integer associated with it. FeatureVectors rely on the integer part of the mapping to efficiently represent the subset of the Alphabet present in the FeatureVector.

    See Also:
    FeatureVector, Instance, Pipe, Serialized Form

    • Constructor Summary

      Constructors 
      Constructor Description
      Alphabet()  
      Alphabet​(int capacity)  
      Alphabet​(int capacity, java.lang.Class entryClass)  
      Alphabet​(java.lang.Class entryClass)  
      Alphabet​(java.lang.Object[] entries)  

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static boolean alphabetsMatch​(AlphabetCarrying object1, AlphabetCarrying object2)
      Convenience method that can often implement alphabetsMatch in classes that implement the AlphabetsCarrying interface.
      java.lang.Object clone()  
      boolean contains​(java.lang.Object entry)  
      void dump()  
      void dump​(java.io.PrintStream out)  
      void dump​(java.io.PrintWriter out)  
      java.lang.Class entryClass()  
      java.util.UUID getInstanceId()  
      boolean growthStopped()  
      java.util.Iterator iterator()  
      int lookupIndex​(java.lang.Object entry)  
      int lookupIndex​(java.lang.Object entry, boolean addIfNotPresent)
      Return -1 if entry isn't present.
      int[] lookupIndices​(java.lang.Object[] objects, boolean addIfNotPresent)  
      java.lang.Object lookupObject​(int index)  
      java.lang.Object[] lookupObjects​(int[] indices)  
      java.lang.Object[] lookupObjects​(int[] indices, java.lang.Object[] buf)
      Returns an array of the objects corresponding to
      java.lang.Object readResolve()
      This gets called after readObject; it lets the object decide whether to return itself or return a previously read in version.
      void setInstanceId​(java.util.UUID id)  
      int size()  
      void startGrowth()  
      void stopGrowth()  
      java.lang.Object[] toArray()  
      java.lang.Object[] toArray​(java.lang.Object[] in)
      Returns an array containing all the entries in the Alphabet.
      java.lang.String toString()
      Return String representation of all Alphabet entries, each separated by a newline.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • Alphabet

        public Alphabet​(int capacity,
                java.lang.Class entryClass)

      • Alphabet

        public Alphabet​(java.lang.Class entryClass)

      • Alphabet

        public Alphabet​(int capacity)

      • Alphabet

        public Alphabet()

      • Alphabet

        public Alphabet​(java.lang.Object[] entries)

    • Method Detail

      • clone

        public java.lang.Object clone()
        Overrides:
        clone in class java.lang.Object

      • lookupIndex

        public int lookupIndex​(java.lang.Object entry,
                       boolean addIfNotPresent)
        Return -1 if entry isn't present.

      • lookupIndex

        public int lookupIndex​(java.lang.Object entry)

      • lookupObject

        public java.lang.Object lookupObject​(int index)

      • toArray

        public java.lang.Object[] toArray()

      • toArray

        public java.lang.Object[] toArray​(java.lang.Object[] in)
        Returns an array containing all the entries in the Alphabet. The runtime type of the returned array is the runtime type of in. If in is large enough to hold everything in the alphabet, then it it used. The returned array is such that for all entries obj, ret[lookupIndex(obj)] = obj .

      • iterator

        public java.util.Iterator iterator()

      • lookupObjects

        public java.lang.Object[] lookupObjects​(int[] indices)

      • lookupObjects

        public java.lang.Object[] lookupObjects​(int[] indices,
                                        java.lang.Object[] buf)
        Returns an array of the objects corresponding to
        Parameters:
        indices - An array of indices to look up
        buf - An array to store the returned objects in.
        Returns:
        An array of values from this Alphabet. The runtime type of the array is the same as buf

      • lookupIndices

        public int[] lookupIndices​(java.lang.Object[] objects,
                           boolean addIfNotPresent)

      • contains

        public boolean contains​(java.lang.Object entry)

      • size

        public int size()

      • stopGrowth

        public void stopGrowth()

      • startGrowth

        public void startGrowth()

      • growthStopped

        public boolean growthStopped()

      • entryClass

        public java.lang.Class entryClass()

      • toString

        public java.lang.String toString()
        Return String representation of all Alphabet entries, each separated by a newline.
        Overrides:
        toString in class java.lang.Object

      • dump

        public void dump()

      • dump

        public void dump​(java.io.PrintStream out)

      • dump

        public void dump​(java.io.PrintWriter out)

      • alphabetsMatch

        public static boolean alphabetsMatch​(AlphabetCarrying object1,
                                     AlphabetCarrying object2)
        Convenience method that can often implement alphabetsMatch in classes that implement the AlphabetsCarrying interface.

      • getInstanceId

        public java.util.UUID getInstanceId()

      • setInstanceId

        public void setInstanceId​(java.util.UUID id)

      • readResolve

        public java.lang.Object readResolve()
                             throws java.io.ObjectStreamException
        This gets called after readObject; it lets the object decide whether to return itself or return a previously read in version. We use a hashMap of instanceIds to determine if we have already read in this object.
        Returns:
        Throws:
        java.io.ObjectStreamException