Parse: f(a, ,c) as full form f(a, Null, c)

- `f(,b,c)` as full form `f(Null, b, c)` - `f(a,b,)` as full form `f(a, b, Null)` - ...
axkr · Aug 4, 2024 · 744846a · 744846a
1 parent eebbca7
commit 744846a
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Showing 4 changed files with 46 additions and 2 deletions.
diff --git a/...ndroid_library/matheclipse-core/src/main/java/org/matheclipse/core/parser/ExprParser.java b/...ndroid_library/matheclipse-core/src/main/java/org/matheclipse/core/parser/ExprParser.java
@@ -344,7 +344,11 @@ private PrefixExprOperator determinePrefixOperator() {
   /** construct the arguments for an expression */
   private void getArguments(final IASTAppendable function) throws SyntaxError {
     do {
-      function.append(parseExpression());
+      if (fToken == TT_COMMA) {
+        function.append(S.Null);
+      } else {
+        function.append(parseExpression());
+      }
 
       if (fToken != TT_COMMA) {
         break;

diff --git a/...ndroid_library/matheclipse-parser/src/main/java/org/matheclipse/parser/client/Parser.java b/...ndroid_library/matheclipse-parser/src/main/java/org/matheclipse/parser/client/Parser.java
@@ -172,7 +172,11 @@ private PrefixOperator determinePrefixOperator() {
   /** construct the arguments for an expression */
   private void getArguments(final FunctionNode function) throws SyntaxError {
     do {
-      function.add(parseExpression());
+      if (fToken == TT_COMMA) {
+        function.add(fFactory.createSymbol("Null"));
+      } else {
+        function.add(parseExpression());
+      }
 
       if (fToken != TT_COMMA) {
         break;

diff --git a/..._library/matheclipse-parser/src/test/java/org/matheclipse/parser/test/ParserTestCase.java b/..._library/matheclipse-parser/src/test/java/org/matheclipse/parser/test/ParserTestCase.java
@@ -716,4 +716,22 @@ void testParser84() {
     ASTNode obj = PARSE_UNRELAXED.parse("x \\[LessEqual] (x^3)");
     assertEquals("LessEqual(x, Power(x, 3))", obj.toString());
   }
+
+  @Test
+  void testParser85() {
+    ASTNode obj = PARSE_UNRELAXED.parse("f[,b,c]");
+    assertEquals("f(Null, b, c)", obj.toString());
+  }
+
+  @Test
+  void testParser86() {
+    ASTNode obj = PARSE_UNRELAXED.parse("f[a, ,c]");
+    assertEquals("f(a, Null, c)", obj.toString());
+  }
+
+  @Test
+  void testParser87() {
+    ASTNode obj = PARSE_UNRELAXED.parse("f[a,b,]");
+    assertEquals("f(a, b, Null)", obj.toString());
+  }
 }
diff --git a/...y/matheclipse-parser/src/test/java/org/matheclipse/parser/test/RelaxedParserTestCase.java b/...y/matheclipse-parser/src/test/java/org/matheclipse/parser/test/RelaxedParserTestCase.java
@@ -91,4 +91,22 @@ void testParser12() {
     ASTNode obj = PARSE_RELAXED.parse("I_m==a*c");
     assertEquals("Equal(I_m, Times(a, c))", obj.toString());
   }
+
+  @Test
+  void testParser13() {
+    ASTNode obj = PARSE_RELAXED.parse("f(,b,c)");
+    assertEquals("f(Null, b, c)", obj.toString());
+  }
+
+  @Test
+  void testParser14() {
+    ASTNode obj = PARSE_RELAXED.parse("f(a, ,c)");
+    assertEquals("f(a, Null, c)", obj.toString());
+  }
+
+  @Test
+  void testParser15() {
+    ASTNode obj = PARSE_RELAXED.parse("f(a,b,)");
+    assertEquals("f(a, b, Null)", obj.toString());
+  }
 }