## org.biojava.bio.symbol
Interface FiniteAlphabet

All Superinterfaces:
  Alphabet, Annotatable, Changeable

All Known Implementing Classes:
  AbstractAlphabet, IntegerAlphabet.SubIntegerAlphabet, SimpleAlphabet, SingletonAlphabet, SoftMaskedAlphabet

    public interface FiniteAlphabet

extends Alphabet

An alphabet over a finite set of Symbols.

This interface makes the distinction between an alphabet over a finite (and possibly small) number of symbols and an Alphabet over an infinite (or extremely large) set of symbols. Within a FiniteAlphabet, the == operator should be sufficient to decide upon equality for all AtomicSymbol instances.

The alphabet functions as the repository of objects in the fly-weight design pattern. Only symbols within an alphabet should appear in object that claim to use the alphabet - otherwise something is in error.

Author:
  Matthew Pocock

Nested Class Summary

Nested classes/interfaces inherited from interface org.biojava.bio.Annotatable
`Annotatable.AnnotationForwarder`

Field Summary

Fields inherited from interface org.biojava.bio.symbol.Alphabet
`EMPTY_ALPHABET, PARSERS, SYMBOLS`

Fields inherited from interface org.biojava.bio.Annotatable
`ANNOTATION`

Method Summary
`void` `addSymbol(Symbol s)` Adds a symbol to this alphabet.
`java.util.Iterator` `iterator()` Retrieve an Iterator over the AtomicSymbols in this FiniteAlphabet.
`void` `removeSymbol(Symbol s)` Remove a symbol from this alphabet.
`int` `size()` The number of symbols in the alphabet.

Methods inherited from interface org.biojava.bio.symbol.Alphabet
`contains, getAlphabets, getAmbiguity, getGapSymbol, getName, getSymbol, getTokenization, validate`

Methods inherited from interface org.biojava.bio.Annotatable
`getAnnotation`

Methods inherited from interface org.biojava.utils.Changeable
`addChangeListener, addChangeListener, isUnchanging, removeChangeListener, removeChangeListener`

Method Detail

### size

    int size()

  The number of symbols in the alphabet.

  Returns:
    the size of the alphabet

### iterator

    java.util.Iterator iterator()

  Retrieve an Iterator over the AtomicSymbols in this FiniteAlphabet.

  Each AtomicSymbol as for which this.contains(as) is true will be returned exactly once by this iterator in no specified order.

  Returns:
    an Iterator over the contained AtomicSymbol objects

### addSymbol

    void addSymbol(Symbol s)
                   throws IllegalSymbolException,
                          ChangeVetoException

  Adds a symbol to this alphabet.

  If the symbol matches more than one AtomicSymbol, then each symbol matching it will be added.

  Parameters:
    `s` - the Symbol to add
  Throws:
    `IllegalSymbolException` - if the symbol is null, or if for any reason it can't be added
    `ChangeVetoException` - if either the alphabet doesn't allow symbols to be added, or the change was vetoed

### removeSymbol

    void removeSymbol(Symbol s)
                      throws IllegalSymbolException,
                             ChangeVetoException

  Remove a symbol from this alphabet.

  If the symbol matches multiple AtomicSymbols, then each matching symbol it will be removed.

  Parameters:
    `s` - the Symbol to removeintGot
  Throws:
    `IllegalSymbolException` - if the symbol is null, or if for any reason it can't be removed
    `ChangeVetoException` - if either the alphabet doesn't allow symbols to be added, or the change was vetoed