blob: 15a5e4ac3580c8a67502120c5e58dc6746773a94 [file] [log] [blame]
package com.googlecode.prolog_cafe.lang;
import com.googlecode.prolog_cafe.exceptions.EvaluationException;
import com.googlecode.prolog_cafe.exceptions.IllegalTypeException;
/**
* Integer.<br>
* The class <code>IntegerTerm</code> wraps a value of primitive type
* <code>int</code>.
* <pre>
* Term t = new IntegerTerm(100);
* int i = ((IntegerTerm)t).intValue();
* </pre>
*
* @author Mutsunori Banbara (banbara@kobe-u.ac.jp)
* @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
* @version 1.0
*/
public class IntegerTerm extends NumberTerm {
/** Holds an <code>int</code> value that this <code>IntegerTerm</code> represents. */
protected int val;
/** Constructs a new Prolog integer that represents the specified <code>int</code> value. */
public IntegerTerm(int i) { val = i; }
/**
* Returns the value of <code>val</code>.
* @see #val
*/
public int value() { return val; }
/* Term */
public boolean unify(Term t, Trail trail) {
if (t.isVariable())
return ((VariableTerm)t).unify(this, trail);
if (! t.isInteger())
return false;
else
return this.val == ((IntegerTerm)t).value();
}
/**
* @return the <code>boolean</code> whose value is
* <code>convertible(Integer.class, type)</code>.
* @see Term#convertible(Class, Class)
*/
public boolean convertible(Class type) { return convertible(Integer.class, type); }
public String name() { return ""; }
/**
* Returns a <code>java.lang.Integer</code> corresponds to this <code>IntegerTerm</code>
* according to <em>Prolog Cafe interoperability with Java</em>.
* @return a <code>java.lang.Integer</code> object equivalent to
* this <code>IntegerTerm</code>.
*/
public Object toJava() { return Integer.valueOf(val); }
/* Object */
/** Returns a string representation of this <code>IntegerTerm</code>. */
public String toString() { return Integer.toString(this.val); }
/**
* Checks <em>term equality</em> of two terms.
* The result is <code>true</code> if and only if the argument is an instance of
* <code>IntegerTerm</code> and has the same <code>int</code> value as this object.
* @param obj the object to compare with. This must be dereferenced.
* @return <code>true</code> if the given object represents a Prolog integer
* equivalent to this <code>IntegerTerm</code>, false otherwise.
* @see #compareTo
*/
public boolean equals(Object obj) {
if (! (obj instanceof IntegerTerm))
return false;
return this.val == ((IntegerTerm)obj).value();
}
public int hashCode() { return this.val; }
/* Comparable */
/**
* Compares two terms in <em>Prolog standard order of terms</em>.<br>
* It is noted that <code>t1.compareTo(t2) == 0</code> has the same
* <code>boolean</code> value as <code>t1.equals(t2)</code>.
* @param anotherTerm the term to compared with. It must be dereferenced.
* @return the value <code>0</code> if two terms are identical;
* a value less than <code>0</code> if this term is <em>before</em> the <code>anotherTerm</code>;
* and a value greater than <code>0</code> if this term is <em>after</em> the <code>anotherTerm</code>.
*/
public int compareTo(Term anotherTerm) { // anotherTerm must be dereferenced.
if (anotherTerm.isVariable() || anotherTerm.isDouble())
return AFTER;
if (! anotherTerm.isInteger())
return BEFORE;
int v = ((IntegerTerm)anotherTerm).value();
if (this.val == v)
return EQUAL;
if (this.val > v)
return AFTER;
return BEFORE;
}
/* NumberTerm */
public int intValue() { return this.val; }
public long longValue() { return (long)(this.val); }
public double doubleValue() { return (double)(this.val); }
public int arithCompareTo(NumberTerm t) {
if (t.isDouble())
return - (t.arithCompareTo(this));
int v = t.intValue();
if (this.val == v)
return EQUAL;
if (this.val > v)
return AFTER;
return BEFORE;
}
public NumberTerm abs() { return new IntegerTerm(Math.abs(this.val)); }
public NumberTerm acos() { return new DoubleTerm(Math.acos(this.doubleValue())); }
public NumberTerm add(NumberTerm t) {
if (t.isDouble())
return t.add(this);
return new IntegerTerm(this.val + t.intValue());
}
/**
* @exception IllegalTypeException if the given argument
* <code>NumberTerm</code> is a floating point number.
*/
public NumberTerm and(NumberTerm t) {
if (t.isDouble())
throw new IllegalTypeException("integer", t);
return new IntegerTerm(this.val & t.intValue());
}
public NumberTerm asin() { return new DoubleTerm(Math.asin(this.doubleValue())); }
public NumberTerm atan() { return new DoubleTerm(Math.atan(this.doubleValue())); }
public NumberTerm ceil() { return this; }
public NumberTerm cos() { return new DoubleTerm(Math.cos(this.doubleValue())); }
/**
* @exception EvaluationException if the given argument
* <code>NumberTerm</code> represents <coe>0</code>.
*/
public NumberTerm divide(NumberTerm t) {
if (t.doubleValue() == 0)
throw new EvaluationException("zero_divisor");
return new DoubleTerm(this.doubleValue() / t.doubleValue());
}
public NumberTerm exp() { return new DoubleTerm(Math.exp(this.doubleValue())); }
public NumberTerm floatIntPart() { throw new IllegalTypeException("float", this); }
public NumberTerm floatFractPart() { throw new IllegalTypeException("float", this); }
public NumberTerm floor() { return this; }
/**
* @exception IllegalTypeException if the given argument
* <code>NumberTerm</code> is a floating point number.
* @exception EvaluationException if the given argument
* <code>NumberTerm</code> represents <coe>0</code>.
*/
public NumberTerm intDivide(NumberTerm t) {
if (t.isDouble())
throw new IllegalTypeException("integer", t);
if (t.intValue() == 0)
throw new EvaluationException("zero_divisor");
return new IntegerTerm((int) (this.val / t.intValue()));
}
/**
* @exception EvaluationException if this object represents <coe>0</code>.
*/
public NumberTerm log() {
if (this.val == 0)
throw new EvaluationException("undefined");
return new DoubleTerm(Math.log(this.doubleValue()));
}
public NumberTerm max(NumberTerm t) {
if (t.isDouble())
return t.max(this);
return new IntegerTerm(Math.max(this.val, t.intValue()));
}
public NumberTerm min(NumberTerm t) {
if (t.isDouble())
return t.min(this);
return new IntegerTerm(Math.min(this.val, t.intValue()));
}
/**
* @exception IllegalTypeException if the given argument
* <code>NumberTerm</code> is a floating point number.
* @exception EvaluationException if the given argument
* <code>NumberTerm</code> represents <coe>0</code>.
*/
public NumberTerm mod(NumberTerm t) {
if (t.isDouble())
throw new IllegalTypeException("integer", t);
if (t.intValue() == 0)
throw new EvaluationException("zero_divisor");
return new IntegerTerm(this.val % t.intValue());
}
public NumberTerm multiply(NumberTerm t) {
if (t.isDouble())
return t.multiply(this);
return new IntegerTerm(this.val * t.intValue());
}
public NumberTerm negate() { return new IntegerTerm(- this.val); }
public NumberTerm not() { return new IntegerTerm(~ this.val); }
/**
* @exception IllegalTypeException if the given argument
* <code>NumberTerm</code> is a floating point number.
*/
public NumberTerm or(NumberTerm t) {
if (t.isDouble())
throw new IllegalTypeException("integer", t);
return new IntegerTerm(this.val | t.intValue());
}
public NumberTerm pow(NumberTerm t) { return new DoubleTerm(Math.pow(this.doubleValue(), t.doubleValue())); }
public NumberTerm rint() { return new DoubleTerm(this.doubleValue()); }
public NumberTerm round() { return this; }
/**
* @exception IllegalTypeException if the given argument
* <code>NumberTerm</code> is a floating point number.
*/
public NumberTerm shiftLeft(NumberTerm t) {
if (t.isDouble())
throw new IllegalTypeException("integer", t);
return new IntegerTerm(this.val << t.intValue());
}
/**
* @exception IllegalTypeException if the given argument
* <code>NumberTerm</code> is a floating point number.
*/
public NumberTerm shiftRight(NumberTerm t) {
if (t.isDouble())
throw new IllegalTypeException("integer", t);
return new IntegerTerm(this.val >> t.intValue());
}
public NumberTerm signum() {return new IntegerTerm((int) Math.signum((double) this.val)); }
public NumberTerm sin() { return new DoubleTerm(Math.sin(this.doubleValue())); }
/**
* @exception EvaluationException if this object represents
* an integer less than <coe>0</code>.
*/
public NumberTerm sqrt() {
if (this.val < 0)
throw new EvaluationException("undefined");
return new DoubleTerm(Math.sqrt(this.doubleValue()));
}
public NumberTerm subtract(NumberTerm t) {
if (t.isDouble())
return new DoubleTerm(this.doubleValue() - t.doubleValue());
return new IntegerTerm(this.val - t.intValue());
}
public NumberTerm tan() { return new DoubleTerm(Math.tan(this.doubleValue())); }
public NumberTerm toDegrees() { return new DoubleTerm(Math.toDegrees(this.doubleValue())); }
public NumberTerm toFloat() { return new DoubleTerm((double) this.val); }
public NumberTerm toRadians() { return new DoubleTerm(Math.toRadians(this.doubleValue())); }
public NumberTerm truncate() { return this; }
/**
* @exception IllegalTypeException if the given argument
* <code>NumberTerm</code> is a floating point number.
*/
public NumberTerm xor(NumberTerm t) {
if (t.isDouble())
throw new IllegalTypeException("integer", t);
return new IntegerTerm(this.val ^ t.intValue());
}
}