Creating an error handler that automatically defines variables on the fly by checking for an 'Undefined Identifier' error.

ID: 326

See: Code = [ErrorCode], Error = [ErrorInfo], Error handling and control flow 
				
					using uCalcSoftware;

var uc = new uCalc();

static void AutoDefineHandler(Handle_uCalc h) {
   var uc = new uCalc(h);
   // Check if the error is specifically an undefined identifier
   if (uc.Error.Code == ErrorCode.Undefined_Identifier) {
      // If so, define the missing variable and instruct uCalc to resume
      Console.WriteLine($"Auto-defining variable: '{uc.Error.Symbol}'");
      uc.DefineVariable(uc.Error.Symbol);
      uc.Error.Response = ErrorHandlerResponse.Resume;
   }
}


uc.Error.AddHandler(AutoDefineHandler);

// 'x' doesn't exist, but the handler will intercept the error and create it.
var Result = uc.EvalStr("x = 10; x * 5");
Console.WriteLine($"Result: {Result}");
				
			
Auto-defining variable: 'x'
Result: 50
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

void ucalc_call AutoDefineHandler(Handle_uCalc h) {
   auto uc = uCalc(h);
   // Check if the error is specifically an undefined identifier
   if (uc.Error().Code() == ErrorCode::Undefined_Identifier) {
      // If so, define the missing variable and instruct uCalc to resume
      cout << "Auto-defining variable: '" << uc.Error().Symbol() << "'" << endl;
      uc.DefineVariable(uc.Error().Symbol());
      uc.Error().Response(ErrorHandlerResponse::Resume);
   }
}

int main() {
   uCalc uc;
   uc.Error().AddHandler(AutoDefineHandler);

   // 'x' doesn't exist, but the handler will intercept the error and create it.
   auto Result = uc.EvalStr("x = 10; x * 5");
   cout << "Result: " << Result << endl;
}
				
			
Auto-defining variable: 'x'
Result: 50
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   
   Public Sub AutoDefineHandler(ByVal h As Handle_uCalc)
      Dim uc As New uCalc(h)
      '// Check if the error is specifically an undefined identifier
      If uc.Error.Code = ErrorCode.Undefined_Identifier Then
         '// If so, define the missing variable and instruct uCalc to resume
         Console.WriteLine($"Auto-defining variable: '{uc.Error.Symbol}'")
         uc.DefineVariable(uc.Error.Symbol)
         uc.Error.Response = ErrorHandlerResponse.Resume
      End If
   End Sub
   
   Public Sub Main()
      Dim uc As New uCalc()
      uc.Error.AddHandler(AddressOf AutoDefineHandler)
      
      '// 'x' doesn't exist, but the handler will intercept the error and create it.
      Dim Result = uc.EvalStr("x = 10; x * 5")
      Console.WriteLine($"Result: {Result}")
   End Sub
End Module
				
			
Auto-defining variable: 'x'
Result: 50
Explore 600+ other examples