WIP #937 N( Equal-expression ) does not return numeric result

Author: axkr

symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/BooleanFunctions.java

@@ -1734,11 +1734,6 @@ public IExpr evaluate(final IAST ast, EvalEngine engine) {
         return S.Undefined;
       }
 
-      IAST evalArgs = engine.evalArgsN(ast, ISymbol.NOATTRIBUTE);
-      if (evalArgs.isPresent()) {
-        return evalArgs;
-      }
-
       if (ast.size() > 2) {
         IExpr.COMPARE_TERNARY b = IExpr.COMPARE_TERNARY.UNDECIDABLE;
         if (ast.isAST2()) {
@@ -2216,11 +2211,6 @@ public IExpr evaluate(IAST ast, EvalEngine engine) {
         return S.True;
       }
 
-      IASTMutable evalArgs = engine.evalArgsN(ast, ISymbol.NOATTRIBUTE);
-      if (evalArgs.isPresent()) {
-        return evalArgs;
-      }
-
       IASTAppendable flattened;
       if ((flattened = EvalAttributes.flattenDeep(ast)).isPresent()) {
         ast = flattened;
@@ -4671,10 +4661,6 @@ private static final class Unequal extends Equal {
 
     @Override
     public IExpr evaluate(final IAST ast, EvalEngine engine) {
-      IASTMutable evalArgs = engine.evalArgsN(ast, ISymbol.NOATTRIBUTE);
-      if (evalArgs.isPresent()) {
-        return evalArgs;
-      }
       if (ast.exists(x -> x.equals(S.Undefined))) {
         return S.Undefined;
       }

symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/GraphicsFunctions.java

@@ -683,10 +683,6 @@ private static final class Labeled extends AbstractCoreFunctionEvaluator {
 
     @Override
     public IExpr evaluate(final IAST ast, EvalEngine engine) {
-      IASTMutable evalArgs = engine.evalArgsN(ast, ISymbol.NOATTRIBUTE);
-      if (evalArgs.isPresent()) {
-        return evalArgs;
-      }
       return F.NIL;
     }
 

symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/eval/EvalEngine.java

@@ -3,6 +3,7 @@
 import java.io.PrintStream;
 import java.io.Serializable;
 import java.util.ArrayDeque;
+import java.util.Arrays;
 import java.util.Deque;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -826,22 +827,6 @@ public void evalArg(final IASTMutable[] result0, final IAST ast, final IExpr arg
 
   }
 
-  /**
-   * Evaluate the arguments of the given <code>ast</code> numerically, if {@link #isNumericMode()}
-   * is <code>true</code> taking the attributes
-   * <code>HoldFirst, NHoldFirst, HoldRest, NHoldRest, NumericFunction</code> into account.
-   *
-   * @param ast
-   * @param attributes
-   * @return <code>F.NIL</code> is no evaluation was possible
-   */
-  public IASTMutable evalArgsN(final IAST ast, final int attributes) {
-    if (isNumericMode()) {
-      return evalArgs(ast, attributes, true);
-    }
-    return F.NIL;
-  }
-
   /**
    * Evaluate the arguments of the given ast, taking the attributes <code>
    * HoldFirst, NHoldFirst, HoldRest, NHoldRest, NumericFunction</code> into account.
@@ -856,6 +841,9 @@ public IASTMutable evalArgs(final IAST ast, final int attributes, boolean numeri
     final int astSize = ast.size();
 
     if (astSize > 1) {
+      if (!numericFunction) {
+        numericFunction = isNumericArg(ast);
+      }
       boolean numericMode = fNumericMode;
       boolean localNumericMode = fNumericMode;
       final boolean isNumericFunction;
@@ -956,6 +944,20 @@ public IASTMutable evalArgs(final IAST ast, final int attributes, boolean numeri
     return F.NIL;
   }
 
+  /**
+   * Test if the arguments of this <code>ast</code> should be evaluated numerically in numeric mode.
+   * 
+   * @param ast
+   * @return
+   */
+  private boolean isNumericArg(final IAST ast) {
+    int id = ast.headID();
+    if (id >= 0) {
+      return Arrays.binarySearch(F.SORTED_NUMERIC_ARGS_IDS, id) >= 0;
+    }
+    return false;
+  }
+
   /**
    * Evaluate an AST with only one argument (i.e. <code>head[arg1]</code>). The evaluation steps are
    * controlled by the header attributes.
@@ -1437,11 +1439,12 @@ private IExpr evalNoAttributes(IASTMutable mutableAST) {
     }
     final int astSize = mutableAST.size();
     final boolean localNumericMode = fNumericMode;
+    final boolean argNumericMode = isNumericArg(mutableAST);
     IASTMutable[] rlist = new IASTMutable[] {F.NIL};
     mutableAST.forEach(1, astSize, (arg, i) -> {
       if (!arg.isUnevaluated()) {
         fNumericMode = localNumericMode;
-        evalArg(rlist, mutableAST, arg, i, false);
+        evalArg(rlist, mutableAST, arg, i, argNumericMode);
       }
     });
     if (rlist[0].isPresent()) {

symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/expression/F.java

@@ -234,6 +234,13 @@ public void createUserSymbol(ISymbol symbol) {}
   public static final AbstractAST.NILPointer INVALID = AbstractAST.INVALID;
   // public final static ISymbol usage = initFinalHiddenSymbol("usage");
 
+  /**
+   * Built-in function IDs those arguments should be evaluated numerically in numeric mode:
+   */
+  public static final int[] SORTED_NUMERIC_ARGS_IDS = new int[] {//
+      ID.Equal, ID.Greater, ID.GreaterEqual, ID.Labeled, ID.Less, ID.LessEqual, ID.Unequal //
+  };
+
   /**
    * Used to represent a formal pattern <code>a_</code> that will be used only for predefined
    * pattern-matching rules and can match one expression.

symja_android_library/matheclipse-core/src/test/java/org/matheclipse/core/system/LowercaseTestCase.java

@@ -15984,6 +15984,10 @@ public void testN() {
         "x==-1.5708");
     check("ConditionalExpression(x==-157079632679/100000000000*C(1),C(1)∈Integers) // N", //
         "ConditionalExpression(x==-1.5708*C(1),C(1)∈Integers)");
+    check("f(1/3)//N", //
+        "f(0.333333)");
+    check("f(1/2*x)//N", //
+        "f(0.5*x)");
     check("N({Labeled(4/3,\"test\")})", //
         "{Labeled(1.33333,test)}");
     check("N(Labeled(4/3,\"test\"))", //