Refactor: use Optional instead of returning null

axkr · Nov 28, 2023 · 34a9d8c · 34a9d8c
1 parent 859cb53
commit 34a9d8c
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Showing 12 changed files with 375 additions and 335 deletions.
diff --git a/..._android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/Algebra.java b/..._android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/Algebra.java
diff --git a/...droid_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/Arithmetic.java b/...droid_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/Arithmetic.java
@@ -38,6 +38,7 @@
 import static org.matheclipse.core.expression.S.Times;
 import static org.matheclipse.core.expression.S.x;
 import static org.matheclipse.core.expression.S.y;
+import java.util.Optional;
 import java.util.function.DoubleFunction;
 import java.util.function.DoubleUnaryOperator;
 import java.util.function.Function;
@@ -1438,16 +1439,17 @@ public IExpr evaluate(final IAST ast, EvalEngine engine) {
           }
 
           if (arg1.isTimes() || arg1.isPower()) {
-            IExpr[] parts = Algebra.fractionalPartsTimesPower((IAST) arg1, true, false, false,
-                false, false, false);
-            if (parts != null && !parts[1].isOne()
-                && !(parts[1].isAST(S.Sign) || parts[0].isAST(S.Sign))) {
-              final IExpr numerator = parts[0];
-              final IExpr denominator = parts[1];
-              IExpr tmp = engine.evaluate(F.Times(F.Sign(numerator), //
-                  F.Power(F.Sign(denominator), F.CN1)));
-              if (!tmp.equals(arg1)) {
-                return F.DirectedInfinity(tmp);
+            Optional<IExpr[]> parts = Algebra.fractionalPartsTimesPower((IAST) arg1, true, false,
+                false, false, false, false);
+            if (parts.isPresent()) {
+              final IExpr numerator = parts.get()[0];
+              final IExpr denominator = parts.get()[1];
+              if (!denominator.isOne() && !(denominator.isAST(S.Sign) || numerator.isAST(S.Sign))) {
+                IExpr tmp = engine.evaluate(F.Times(F.Sign(numerator), //
+                    F.Power(F.Sign(denominator), F.CN1)));
+                if (!tmp.equals(arg1)) {
+                  return F.DirectedInfinity(tmp);
+                }
               }
             }
           }

diff --git a/..._library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/MinMaxFunctions.java b/..._library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/MinMaxFunctions.java
@@ -4,6 +4,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Optional;
 import java.util.function.Supplier;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -396,10 +397,10 @@ public IExpr visit(IASTMutable ast) {
           return F.NIL;
         }
         if (ast.isTimes()) {
-          IExpr[] parts = Algebra.fractionalParts(ast, false);
-          if (parts != null) {
-            IExpr numerator = parts[0];
-            IExpr denominator = parts[1];
+          Optional<IExpr[]> parts = Algebra.fractionalParts(ast, false);
+          if (parts.isPresent()) {
+            IExpr numerator = parts.get()[0];
+            IExpr denominator = parts.get()[1];
             if (!denominator.isFree(variable)) {
               numerator.accept(this);
               return roots(denominator);

diff --git a/..._library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/SeriesFunctions.java b/..._library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/SeriesFunctions.java
@@ -3,6 +3,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.function.Function;
 import javax.annotation.Nullable;
 import org.matheclipse.core.basic.Config;
@@ -828,12 +829,12 @@ private static IExpr substituteInfinity(final IAST arg1, LimitData data, EvalEng
       IExpr y = F.Power(x, F.CN1); // substituting by 1/x
       IExpr temp = F.evalQuiet(F.subst(arg1, x, y));
       if (temp.isTimes()) {
-        IExpr[] parts =
+        Optional<IExpr[]> parts =
             Algebra.fractionalPartsTimesPower((IAST) temp, false, false, true, true, true, true);
-        if (parts != null) {
-          if (!parts[1].isOne()) { // denominator != 1
+        if (parts.isPresent()) {
+          if (!parts.get()[1].isOne()) { // denominator != 1
             LimitData ndData = new LimitData(x, F.C0, F.Rule(x, F.C0), data.direction());
-            temp = numeratorDenominatorLimit(parts[0], parts[1], ndData, engine);
+            temp = numeratorDenominatorLimit(parts.get()[0], parts.get()[1], ndData, engine);
             if (temp.isPresent()) {
               return temp;
             }
@@ -849,9 +850,9 @@ private static IExpr timesLimit(final IAST timesAST, LimitData data, EvalEngine
       if (!isFreeResult.arg1().isOne()) {
         return F.Times(isFreeResult.arg1(), data.limit(isFreeResult.arg2()));
       }
-      IExpr[] parts =
+      Optional<IExpr[]> parts =
           Algebra.fractionalPartsTimesPower(timesAST, false, false, true, true, true, true);
-      if (parts == null) {
+      if (parts.isEmpty()) {
         IAST[] timesPolyFiltered = timesAST.filter(x -> x.isPolynomial(data.variable));
         if (timesPolyFiltered[0].size() > 1 && timesPolyFiltered[1].size() > 1) {
           IExpr first = engine.evaluate(data.limit(timesPolyFiltered[0].oneIdentity1()));
@@ -886,8 +887,8 @@ private static IExpr timesLimit(final IAST timesAST, LimitData data, EvalEngine
         }
       } else {
 
-        IExpr numerator = parts[0];
-        IExpr denominator = parts[1];
+        IExpr numerator = parts.get()[0];
+        IExpr denominator = parts.get()[1];
         IExpr limit = data.limitValue();
         ISymbol symbol = data.variable();
         if (limit.isInfinity() || limit.isNegativeInfinity()) {
@@ -901,7 +902,7 @@ private static IExpr timesLimit(final IAST timesAST, LimitData data, EvalEngine
           }
         }
 
-        IExpr plusResult = Algebra.partsApart(parts, symbol, engine);
+        IExpr plusResult = Algebra.partsApart(parts.get(), symbol, engine);
         // Algebra.partialFractionDecompositionRational(new PartialFractionGenerator(),
         // parts,symbol);
         if (plusResult.isPlus()) {
@@ -1095,9 +1096,10 @@ public IExpr evaluate(final IAST ast, EvalEngine engine) {
               return F.NIL;
             }
             if (function.isTimes()) {
-              IExpr[] numeratorDenominatorParts = Algebra.fractionalParts(function, false);
-              if (numeratorDenominatorParts != null) {
-                return quotientTaylorFunction(numeratorDenominatorParts, x, x0, m, n);
+              Optional<IExpr[]> numeratorDenominatorParts =
+                  Algebra.fractionalParts(function, false);
+              if (numeratorDenominatorParts.isPresent()) {
+                return quotientTaylorFunction(numeratorDenominatorParts.get(), x, x0, m, n);
               }
             }
 
@@ -1693,10 +1695,10 @@ public static ASTSeriesData seriesDataRecursive(final IExpr function, IExpr x, I
         return temp;
       }
     } else if (function.isTimes()) {
-      IExpr[] numeratorDenominatorParts = Algebra.fractionalParts(function, false);
-      if (numeratorDenominatorParts != null) {
+      Optional<IExpr[]> numeratorDenominatorParts = Algebra.fractionalParts(function, false);
+      if (numeratorDenominatorParts.isPresent()) {
         ASTSeriesData sd =
-            Algebra.polynomialTaylorSeries(numeratorDenominatorParts, x, x0, n, denominator);
+            Algebra.polynomialTaylorSeries(numeratorDenominatorParts.get(), x, x0, n, denominator);
         if (sd != null) {
           return sd;
         }

diff --git a/...ry/matheclipse-core/src/main/java/org/matheclipse/core/form/mathml/MathMLFormFactory.java b/...ry/matheclipse-core/src/main/java/org/matheclipse/core/form/mathml/MathMLFormFactory.java
@@ -6,6 +6,7 @@
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apfloat.Apcomplex;
@@ -961,13 +962,14 @@ public boolean convert(final StringBuilder buf, final IAST f, final int preceden
      */
     public boolean convertTimesFraction(final StringBuilder buf, final IAST f, final int precedence,
         final boolean caller) {
-      IExpr[] parts = Algebra.fractionalPartsTimesPower(f, false, true, false, false, false, false);
-      if (parts == null) {
+      Optional<IExpr[]> parts =
+          Algebra.fractionalPartsTimesPower(f, false, true, false, false, false, false);
+      if (parts.isEmpty()) {
         convertTimesOperator(buf, f, precedence, false, caller);
         return true;
       }
-      final IExpr numerator = parts[0];
-      final IExpr denominator = parts[1];
+      final IExpr numerator = parts.get()[0];
+      final IExpr denominator = parts.get()[1];
       precedenceOpen(buf, precedence);
       if (!denominator.isOne()) {
         boolean arg1Negate = false;

diff --git a/.../matheclipse-core/src/main/java/org/matheclipse/core/form/output/ASCIIPrettyPrinter3.java b/.../matheclipse-core/src/main/java/org/matheclipse/core/form/output/ASCIIPrettyPrinter3.java
@@ -1,6 +1,7 @@
 package org.matheclipse.core.form.output;
 
 import java.io.PrintWriter;
+import java.util.Optional;
 import org.matheclipse.core.builtin.Algebra;
 import org.matheclipse.core.expression.S;
 import org.matheclipse.core.interfaces.IAST;
@@ -207,14 +208,15 @@ private void convertTimes(IAST times, final int precedence, boolean caller) {
    * @param ast
    */
   private void convertTimesPowerFraction(IAST ast, final int precedence) {
-    IExpr[] parts = Algebra.fractionalPartsTimesPower(ast, true, false, false, false, false, false);
+    Optional<IExpr[]> parts =
+        Algebra.fractionalPartsTimesPower(ast, true, false, false, false, false, false);
     // IExpr[] parts = Algebra.getFractionalParts(ast, false);
-    if (parts == null) {
+    if (parts.isEmpty()) {
       print(ast.toString());
       return;
     }
-    final IExpr numerator = parts[0];
-    final IExpr denominator = parts[1];
+    final IExpr numerator = parts.get()[0];
+    final IExpr denominator = parts.get()[1];
     if (!denominator.isOne()) {
       printFraction(numerator.toString(), denominator.toString());
     } else {

diff --git a/...ry/matheclipse-core/src/main/java/org/matheclipse/core/form/output/DoubleFormFactory.java b/...ry/matheclipse-core/src/main/java/org/matheclipse/core/form/output/DoubleFormFactory.java
@@ -2,6 +2,7 @@
 
 import java.io.IOException;
 import java.math.BigInteger;
+import java.util.Optional;
 import org.apfloat.Apcomplex;
 import org.apfloat.Apfloat;
 import org.hipparchus.linear.RealMatrix;
@@ -577,20 +578,20 @@ private void convertPlusOperatorReversed(final StringBuilder buf, final IAST plu
 
   private void convertTimesFraction(final StringBuilder buf, final IAST timesAST,
       final InfixOperator oper, final int precedence, boolean caller) {
-    IExpr[] parts =
+    Optional<IExpr[]> parts =
         Algebra.fractionalPartsTimesPower(timesAST, true, false, false, false, false, false);
-    if (parts == null) {
+    if (parts.isEmpty()) {
       convertTimesOperator(buf, timesAST, oper, precedence, caller);
       return;
     }
-    final IExpr numerator = parts[0];
-    final IExpr denominator = parts[1];
+    final IExpr numerator = parts.get()[0];
+    final IExpr denominator = parts.get()[1];
     if (!denominator.isOne()) {
       int currPrecedence = oper.getPrecedence();
       if (currPrecedence < precedence) {
         append(buf, "(");
       }
-      final IExpr fraction = parts[2];
+      final IExpr fraction = parts.get()[2];
       if (fraction != null) {
         convertNumber(buf, (IReal) fraction, Precedence.PLUS, caller);
         append(buf, "*");

diff --git a/...ry/matheclipse-core/src/main/java/org/matheclipse/core/form/output/OutputFormFactory.java b/...ry/matheclipse-core/src/main/java/org/matheclipse/core/form/output/OutputFormFactory.java
@@ -3,6 +3,7 @@
 import java.io.IOException;
 import java.math.BigInteger;
 import java.util.List;
+import java.util.Optional;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apfloat.Apcomplex;
@@ -904,20 +905,20 @@ public void convertPlusArgument(final Appendable buf, IExpr plusArg, boolean cal
 
   private void convertTimesFraction(final Appendable buf, final IAST timesAST,
       final InfixOperator oper, final int precedence, boolean caller) throws IOException {
-    IExpr[] parts =
+    Optional<IExpr[]> parts =
         Algebra.fractionalPartsTimesPower(timesAST, true, false, false, false, false, false);
-    if (parts == null) {
+    if (parts.isEmpty()) {
       convertTimesOperator(buf, timesAST, oper, precedence, caller);
       return;
     }
-    final IExpr numerator = parts[0];
-    final IExpr denominator = parts[1];
+    final IExpr numerator = parts.get()[0];
+    final IExpr denominator = parts.get()[1];
     if (!denominator.isOne()) {
       int currPrecedence = oper.getPrecedence();
       if (currPrecedence < precedence) {
         append(buf, "(");
       }
-      final IExpr fraction = parts[2];
+      final IExpr fraction = parts.get()[2];
       if (fraction != null) {
         convertNumber(buf, (IReal) fraction, Precedence.PLUS, caller);
         append(buf, "*");

diff --git a/..._library/matheclipse-core/src/main/java/org/matheclipse/core/form/tex/TeXFormFactory.java b/..._library/matheclipse-core/src/main/java/org/matheclipse/core/form/tex/TeXFormFactory.java
@@ -4,6 +4,7 @@
 import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Optional;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apfloat.Apcomplex;
@@ -1113,21 +1114,21 @@ public boolean convert(final StringBuilder buffer, final IAST f, final int prece
 
     private void convertTimesFraction(final StringBuilder buf, final IAST timesAST,
         final InfixOperator oper, final int precedence, boolean caller) {
-      IExpr[] parts =
+      Optional<IExpr[]> parts =
           Algebra.fractionalPartsTimesPower(timesAST, true, false, false, false, false, false);
-      if (parts == null) {
+      if (parts.isEmpty()) {
         convertTimesOperator(buf, timesAST, oper, precedence, caller);
         return;
       }
-      IExpr numerator = parts[0];
-      final IExpr denominator = parts[1];
+      IExpr numerator = parts.get()[0];
+      final IExpr denominator = parts.get()[1];
       if (!denominator.isOne()) {
         boolean isNegative = numerator.isNegativeSigned();
         if (isNegative) {
           numerator = numerator.negate();
         }
         precedenceOpen(buf, precedence);
-        final IExpr fraction = parts[2];
+        final IExpr fraction = parts.get()[2];
         if (fraction != null) {
           fFactory.convertNumber(buf, fraction, Precedence.PLUS, caller);
           buf.append(fFactory.symbolOptions.getTimesSymbol());

diff --git a/...rary/matheclipse-core/src/main/java/org/matheclipse/core/reflection/system/Integrate.java b/...rary/matheclipse-core/src/main/java/org/matheclipse/core/reflection/system/Integrate.java
@@ -8,6 +8,7 @@
 import static org.matheclipse.core.expression.F.Times;
 import static org.matheclipse.core.expression.S.Integrate;
 import java.util.HashSet;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -675,9 +676,9 @@ private static IExpr callRestIntegrate(IAST arg1, final IExpr x, final EvalEngin
 
       if (arg1AST.size() >= 3 && arg1AST.isFree(S.Integrate) && arg1AST.isPlusTimesPower()) {
         if (!arg1AST.isEvalFlagOn(IAST.IS_DECOMPOSED_PARTIAL_FRACTION) && x.isSymbol()) {
-          IExpr[] parts = Algebra.fractionalParts(arg1, true);
-          if (parts != null) {
-            IExpr temp = Algebra.partsApart(parts, x, engine);
+          Optional<IExpr[]> parts = Algebra.fractionalParts(arg1, true);
+          if (parts.isPresent()) {
+            IExpr temp = Algebra.partsApart(parts.get(), x, engine);
             if (temp.isPresent() && !temp.equals(arg1)) {
               if (temp.isPlus()) {
                 return mapIntegrate((IAST) temp, x);

diff --git a/...se-core/src/main/java/org/matheclipse/core/reflection/system/InverseLaplaceTransform.java b/...se-core/src/main/java/org/matheclipse/core/reflection/system/InverseLaplaceTransform.java
@@ -1,5 +1,6 @@
 package org.matheclipse.core.reflection.system;
 
+import java.util.Optional;
 import org.matheclipse.core.basic.Config;
 import org.matheclipse.core.builtin.Algebra;
 import org.matheclipse.core.eval.EvalEngine;
@@ -159,9 +160,9 @@ public IExpr evaluate(final IAST ast, EvalEngine engine) {
           }
         }
         if (arg1.isTimes() || arg1.isPower()) {
-          IExpr[] parts = Algebra.fractionalParts(arg1, false);
-          if (parts != null) {
-            IExpr temp = Algebra.partsApart(parts, s, engine);
+          Optional<IExpr[]> parts = Algebra.fractionalParts(arg1, false);
+          if (parts.isPresent()) {
+            IExpr temp = Algebra.partsApart(parts.get(), s, engine);
             // IExpr temp = Algebra.partialFractionDecompositionRational(new
             // PartialFractionGenerator(),
             // parts,s);

diff --git a/...roid_library/matheclipse-core/src/test/java/org/matheclipse/core/system/MainTestCase.java b/...roid_library/matheclipse-core/src/test/java/org/matheclipse/core/system/MainTestCase.java
@@ -1,7 +1,8 @@
 package org.matheclipse.core.system;
 
+import static org.junit.Assert.assertEquals;
 import java.io.StringWriter;
-
+import java.util.Optional;
 import org.junit.Test;
 import org.matheclipse.core.basic.Config;
 import org.matheclipse.core.builtin.Algebra;
@@ -12,8 +13,6 @@
 import org.matheclipse.core.interfaces.IExpr;
 import org.matheclipse.parser.client.ParserConfig;
 
-import static org.junit.Assert.assertEquals;
-
 /** Tests system.reflection classes */
 public class MainTestCase extends ExprEvaluatorTestCase {
 
@@ -3343,9 +3342,9 @@ public void testSystem400() {
     EvalEngine engine = EvalEngine.get();
     IExpr exprNumerator = engine.parse("8+12*x+20*x^2+12*x^3+8*x^4+3*x^5");
     IExpr exprDenominator = engine.parse("8*x+12*x^3+6*x^5+x^7");
-    IExpr[] result = Algebra.cancelGCD(exprNumerator, exprDenominator);
-    assertEquals(result[0].toString(), "1");
-    assertEquals(result[1].toString(), "4+6*x+8*x^2+3*x^3");
+    Optional<IExpr[]> result = Algebra.cancelGCD(exprNumerator, exprDenominator);
+    assertEquals(result.get()[0].toString(), "1");
+    assertEquals(result.get()[1].toString(), "4+6*x+8*x^2+3*x^3");
   }
 
   @Test