orbital.moon.logic
Class UniqueSymbol

java.lang.Object
  orbital.logic.sign.SymbolBase
      orbital.moon.logic.UniqueSymbol

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable, Symbol, Typed, Variable

public final class UniqueSymbol
extends SymbolBase

A new unique symbol that is distinct from all others. UniqueSymbols will only be equal to themselves (compared with ==). Note that the signifier IDs are used for printing, and for comparison of Symbols with UniqueSymbols, but for comparisons of UniqueSymbols with Symbols (then that's achieved by reference comparison).

See Also:

Serialized Form

Invariants:

(this.equals(b) ⇔ this == b) ∧ this.hashCode() == System.identityHashCode(this)

Field Summary

Fields inherited from class orbital.logic.sign.SymbolBase

BOOLEAN_ATOM, UNIVERSAL_ATOM

Constructor Summary

UniqueSymbol(java.lang.String signifierPrefix, Type type, Notation.NotationSpecification notation, boolean variable)
Create a new unique symbol of (display) signifier starting with signifierPrefix.

UniqueSymbol(Type type, Notation.NotationSpecification notation, boolean variable)

Method Summary

boolean	equals(java.lang.Object o) Compares two symbols for equality according to their three components.
int	hashCode() Returns the hash code value for this symbol.
void	setNotation(Notation.NotationSpecification notation) Set the notation used when this symbol occurs.
void	setSignifier(java.lang.String signifier) Set the signifier representing this symbol.
void	setSpecification(Functor.Specification spec)

Methods inherited from class orbital.logic.sign.SymbolBase

compareTo, getNotation, getSignifier, getType, isVariable, setType, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

UniqueSymbol

public UniqueSymbol(java.lang.String signifierPrefix,
                    Type type,
                    Notation.NotationSpecification notation,
                    boolean variable)

Create a new unique symbol of (display) signifier starting with signifierPrefix.

UniqueSymbol

public UniqueSymbol(Type type,
                    Notation.NotationSpecification notation,
                    boolean variable)

Method Detail

equals

public final boolean equals(java.lang.Object o)

Description copied from interface: Symbol

Compares two symbols for equality according to their three components. Two symbols are equal if they have the same signifier, type specification and notation. Then it should be asserted that they are either both variable, or both constant, because the sets of variable symbols and constant symbols are usually assumed disjunct.

Specified by:

equals in interface Symbol

Overrides:

equals in class SymbolBase

hashCode

public final int hashCode()

Description copied from interface: Symbol

Returns the hash code value for this symbol. The hash code of a symbol is defined to be the bitwise exclusive or of its components: signifier, type specification, and notation.

Specified by:

hashCode in interface Symbol

Overrides:

hashCode in class SymbolBase

setSignifier

public void setSignifier(java.lang.String signifier)

Description copied from interface: Symbol

Set the signifier representing this symbol.

Specified by:

setSignifier in interface Symbol

Overrides:

setSignifier in class SymbolBase

setSpecification

public void setSpecification(Functor.Specification spec)

setNotation

public void setNotation(Notation.NotationSpecification notation)

Description copied from interface: Symbol

Set the notation used when this symbol occurs. This includes precedence and associativity information, as well.

Specified by:

setNotation in interface Symbol

Overrides:

setNotation in class SymbolBase

Parameters:

notation - the notation used when this symbol occurs.