Introduce the "torational" operator

urbic · May 8, 2024 · 6a80474 · 6a80474
1 parent 483c05e
commit 6a80474
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Showing 6 changed files with 77 additions and 16 deletions.
diff --git a/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyBigFraction.java b/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyBigFraction.java
@@ -118,14 +118,6 @@ public PsyIntegral psyToIntegral()
 		return null;
 	}
 
-	@Override
-	public PsyInteger psyCmp(final PsyRealNumeric oRealNumeric)
-	{
-		// TODO
-		System.err.println("PsyBigFraction::psyCmp");
-		return null;
-	}
-
 	@Override
 	public PsyReal psyRound()
 	{

diff --git a/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyConvertableToRational.java b/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyConvertableToRational.java
@@ -0,0 +1,18 @@
+package coneforest.psylla.core;
+
+import coneforest.psylla.*;
+
+@Type("convertabletorational")
+public interface PsyConvertableToRational
+	extends PsyObject
+{
+	public PsyRational psyToRational()
+		throws PsyErrorException;
+
+	/**
+	*	Context action of the {@code torational} operator.
+	*/
+	@OperatorType("torational")
+	public static final ContextAction PSY_TORATIONAL
+		=ContextAction.<PsyConvertableToRational>ofFunction(PsyConvertableToRational::psyToRational);
+}
diff --git a/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyFraction.java b/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyFraction.java
@@ -115,17 +115,10 @@ public PsyIntegral psyToIntegral()
 		return null;
 	}
 
-	@Override
-	public PsyInteger psyCmp(final PsyRealNumeric oRealNumeric)
-	{
-		// TODO
-		return null;
-	}
-
 	@Override
 	public PsyReal psyRound()
 	{
-		return new PsyReal(Math.round((double)numerator/(double)denominator));
+		return new PsyReal(Math.round(doubleValue()));
 	}
 
 	@Override

diff --git a/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyRational.java b/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyRational.java
@@ -16,6 +16,11 @@ public sealed interface PsyRational
 {
 	public BigInteger bigIntegerValue();
 
+	default public PsyRational rationalValue()
+	{
+		return this;
+	}
+
 	/**
 	*	Returns an {@code integral} numerator of this fraction.
 	*
@@ -30,6 +35,12 @@ public sealed interface PsyRational
 	*/
 	public PsyIntegral psyDenominator();
 
+	@Override
+	default public PsyRational psyToRational()
+	{
+		return this;
+	}
+
 	@Override
 	default public PsyRational psyNeg()
 	{
@@ -152,6 +163,7 @@ default public int cmp(final PsyRealNumeric oNumeric)
 		if(oNumeric instanceof PsyRational oRational)
 			return psyNumerator().psyMul(oRational.psyDenominator())
 					.cmp(psyDenominator().psyMul(oRational.psyNumerator()));
+		// TODO
 		return Double.compare(doubleValue(), oNumeric.doubleValue());
 	}
 

diff --git a/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyReal.java b/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyReal.java
@@ -2,6 +2,7 @@
 
 import coneforest.psylla.*;
 import java.math.BigDecimal;
+import java.math.BigInteger;
 
 /**
 *	The representation of {@code real}.
@@ -48,6 +49,40 @@ public double doubleValue()
 		return value;
 	}
 
+	@Override
+	public PsyRational rationalValue()
+		throws PsyUndefinedResultException
+	{
+		if(value==0.D||value==-0.D)
+			return PsyInteger.ZERO;
+		if(Double.isNaN(value)||Double.isInfinite(value))
+			throw new PsyUndefinedResultException();
+
+		final long bits=Double.doubleToLongBits(value);
+		final long mantissa=bits&0x000FFFFFFFFFFFFFL;
+		final int exponent=(int)((bits&0x7FF0000000000000L)>>52);
+
+		if(exponent==0)
+			return (PsyRational)PsyInteger
+					.of((bits&0x8000000000000000L)==0L? mantissa: -mantissa)
+					.psyDiv(new PsyBigInteger(BigInteger.ZERO.flipBit(-51-Double.MAX_EXPONENT)));
+
+		final int pow=exponent-Double.MAX_EXPONENT;
+
+		PsyRational retval=(PsyRational)PsyInteger.of(mantissa)
+				.psyDiv(PsyInteger.of(0x10000000000000L))
+				.psyAdd(PsyInteger.ONE);
+		if((bits&0x8000000000000000L)!=0L)
+			retval=retval.psyNeg();
+		return (PsyRational)(pow>=0?
+				retval.psyMul((pow<63)?
+						PsyInteger.of(1L<<pow):
+						new PsyBigInteger(BigInteger.ZERO.flipBit(pow))):
+				retval.psyDiv((-pow<63)?
+						PsyInteger.of(1L<<-pow):
+						new PsyBigInteger(BigInteger.ZERO.flipBit(-pow))));
+	}
+
 	@Override
 	public PsyReal psyNeg()
 	{

diff --git a/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyRealNumeric.java b/src/main/java/coneforest.psylla/coneforest/psylla/core/PsyRealNumeric.java
@@ -11,6 +11,7 @@ public sealed interface PsyRealNumeric
 		PsyNumeric,
 		PsyConvertableToInteger,
 		PsyConvertableToIntegral,
+		PsyConvertableToRational,
 		PsyConvertableToReal,
 		PsyScalar<PsyRealNumeric>
 	permits
@@ -24,6 +25,16 @@ public sealed interface PsyRealNumeric
 
 	public double doubleValue();
 
+	public PsyRational rationalValue()
+		throws PsyUndefinedResultException;
+
+	@Override
+	default public PsyRational psyToRational()
+		throws PsyUndefinedResultException
+	{
+		return rationalValue();
+	}
+
 	@Override
 	default public double realValue()
 	{