feat: modify implicit logic to support double equals expression

Author: atulya-srivastava

src/core/Core/Application.cpp

@@ -257,16 +257,43 @@ ExitStatus App::Application::run() {
 
         // check for implicit form: f(x,y) = g(x,y)
         if (!plotted) {
-          size_t equals_pos = findTopLevelEquals(func_str);
+          size_t equals_pos = findTopLevelEquals(func_str);      
+          bool has_double_equals = hasEqualsEqualsOperator(func_str);
+
+          if (equals_pos != std::string::npos || has_double_equals) {
 
-          if (equals_pos != std::string::npos) {
-            // split into LHS and RHS
-            std::string lhs = trim(func_str.substr(0, equals_pos));
-            std::string rhs = trim(func_str.substr(equals_pos + 1));
-            
-            // create expression: LHS - RHS
-            std::string implicit_expr = "(" + lhs + ") - (" + rhs + ")";
-            
+            std::string implicit_expr;
+
+            if (has_double_equals) {
+              // Handle == operator
+              std::string temp_str = func_str;
+              int depth = 0;
+              size_t eq_pos = std::string::npos;
+              
+              for (size_t i = 0; i < temp_str.size() - 1; ++i) {
+                char c = temp_str[i];
+                if (c == '(') ++depth;
+                else if (c == ')') --depth;
+                else if (depth == 0 && c == '=' && temp_str[i+1] == '=') {
+                  eq_pos = i;
+                  break;
+                }
+              }
+              
+              if (eq_pos != std::string::npos) {
+                std::string lhs = trim(temp_str.substr(0, eq_pos));
+                std::string rhs = trim(temp_str.substr(eq_pos + 2)); // +2 to skip ==
+                implicit_expr = "(" + lhs + ") - (" + rhs + ")";
+              }
+            } else {
+              // Handle = operator
+              std::string lhs = trim(func_str.substr(0, equals_pos));
+              std::string rhs = trim(func_str.substr(equals_pos + 1));
+              implicit_expr = "(" + lhs + ") - (" + rhs + ")";
+            }
+
+            if (!implicit_expr.empty()) {
+              
             // setup exprtk with x and y variables
             double x = 0.0, y = 0.0;
             exprtk::symbol_table<double> symbolTable;
@@ -341,7 +368,8 @@ ExitStatus App::Application::run() {
                 }
               }
 
-              plotted = true;
+                plotted = true;
+              }
             }
           }
         }