Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      
      '// This example is mainly meant for C++ where it works with ordinary scalar variables
      '// See the other example where we work with a uCalc array
      
      '// 1. Use an array so the data lives on the heap as a reference type
      '// Boxing is used for scalar variables; a boxed copy of the scalar disconnected from the uCalc
      '// variable would prevent the example from working as expected.
      '// You technically can get around this with the C# "unsafe" directive, but it's not recommended
      Dim myHostVar() As Double = { 1234.5 }
      
      '// 2. Pin the array
      Dim myHostVarHandle = System.Runtime.InteropServices.GCHandle.Alloc(myHostVar, System.Runtime.InteropServices.GCHandleType.Pinned)
      
      '// 3. Bind the uCalc variable to the pinned memory address
      uc.DefineVariable("myVar", myHostVarHandle.AddrOfPinnedObject())
      
      Console.WriteLine(uc.Eval("myVar")) '// Output: 1234.5
      
      '// Changing the uCalc variable updates the pinned array
      uc.Eval("myVar = 456")
      
      '// The change is reflected in the C# array
      Console.WriteLine(myHostVar(0)) '// Output: 456
      
      '// Changing the C# array updates uCalc
      myHostVar(0) = 9876
      
      Console.WriteLine(uc.Eval("myVar")) '// Output: 9876
      
      '// Fast Parse & Evaluate loop
      Dim expr = uc.Parse("myVar * 10")
      For myHostVar(0) = 1 To 5
         Console.WriteLine(expr.Evaluate())
      Next
      '// Don't forget to free the handle when you are completely done with the parser instance
      myHostVarHandle.Free()
      
   End Sub
End Module