using uCalcSoftware;

var uc = 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
double[] myHostVar = new double[] { 1234.5 };

// 2. Pin the array
var 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
var expr = uc.Parse("myVar * 10");
for (myHostVar[0] = 1; myHostVar[0] <= 5; myHostVar[0]++) {
   Console.WriteLine(expr.Evaluate());
}

// Don't forget to free the handle when you are completely done with the parser instance
myHostVarHandle.Free();