ua.gradsoft.termware
Class NILTerm

java.lang.Object
  ua.gradsoft.termware.Term
      ua.gradsoft.termware.AbstractPrimitiveTerm
          ua.gradsoft.termware.NILTerm

All Implemented Interfaces:

Serializable, Cloneable

public final class NILTerm
extends AbstractPrimitiveTerm

Term, which represents NIL

See Also:

Serialized Form

Constructor Summary

NILTerm()

Method Summary

boolean	eq(Term x)
String	getName() return name of term.
Object	getNameIndex() get index of name in instance symbol table.
static Term	getNILTerm() return Nil singleton
Number	getNumber() already throws UnsupportedOperationException
int	getPrimaryType0() return code of level-0 primary type
boolean	isNil() is term is nil ?
boolean	isNumber() is term is Number ?
void	print(PrintWriter out) print term to out.
Term	termClone() since term is immutable - do nothing
int	termCompare(Term x) compare functions.

Methods inherited from class ua.gradsoft.termware.AbstractPrimitiveTerm

boundEquals, boundUnify, clone, concreteOrder, createSame, emptyFv, findSubtermIndexBoundEqualsTo, freeEquals, freeUnify, getArity, getBigDecimal, getBigInteger, getBoolean, getByte, getChar, getDouble, getFloat, getInt, getJavaObject, getLong, getPatternName, getPatternNameIndex, getShort, getString, getSubtermAt, getTerm, getXIndex, isAtom, isBigDecimal, isBigInteger, isBoolean, isByte, isChar, isComplexTerm, isDouble, isFloat, isInt, isJavaObject, isLong, isShort, isString, isX, maxFv, minFv, setSubtermAt, shiftFv, subst, substInside

Methods inherited from class ua.gradsoft.termware.Term

containsSubtermBoundEqualsTo, getAsBigDecimal, getAsBigInteger, getAsBoolean, getAsByte, getAsChar, getAsDouble, getAsFloat, getAsInt, getAsJavaObject, getAsLong, getAsNumber, getAsShort, getAsString, getPrimaryType1, print, println, println

Methods inherited from class java.lang.Object

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

Constructor Detail

NILTerm

public NILTerm()

Method Detail

getNILTerm

public static final Term getNILTerm()

return Nil singleton

getPrimaryType0

public final int getPrimaryType0()

Description copied from class: Term

return code of level-0 primary type

Specified by:

getPrimaryType0 in class Term

Returns:

PrimaryTypes.NIL

See Also:

PrimaryTypes

isNil

public final boolean isNil()

Description copied from class: Term

is term is nil ?

Overrides:

isNil in class AbstractPrimitiveTerm

Returns:

true

isNumber

public final boolean isNumber()

Description copied from class: Term

is term is Number ?

Specified by:

isNumber in class Term

Returns:

false

getNumber

public final Number getNumber()
                       throws UnsupportedOperationException

already throws UnsupportedOperationException

Specified by:

getNumber in class Term

Returns:

number value

Throws:

UnsupportedOperationException

getName

public final String getName()

return name of term.

Specified by:

getName in class AbstractPrimitiveTerm

Returns:

"NIL"

getNameIndex

public final Object getNameIndex()

Description copied from class: Term

get index of name in instance symbol table. If name is not inde (during unifications names are compared by indexes. This allows to speedup unification process)

Overrides:

getNameIndex in class AbstractPrimitiveTerm

eq

public final boolean eq(Term x)

Specified by:

eq in class AbstractPrimitiveTerm

termCompare

public final int termCompare(Term x)

Description copied from class: Term

compare functions. define ordering on set of terms. Note, that ordering is not the same as Java build-in compare.

Specified by:

termCompare in class AbstractPrimitiveTerm

Parameters:

x - - term to compare

termClone

public final Term termClone()

since term is immutable - do nothing

Specified by:

termClone in class AbstractPrimitiveTerm

print

public final void print(PrintWriter out)

Description copied from class: AbstractPrimitiveTerm

print term to out. does not expect recursion.

Specified by:

print in class AbstractPrimitiveTerm

Parameters:

out - - PrintWriter, where to print term.