public void TestMerge()
{
var scope1 = new InterpreterScope();
scope1.DefineVariable(new VariableDefinitionExpression("a"), new IntegerConstantExpression(1));
var scope2 = new InterpreterScope();
scope2.DefineVariable(new VariableDefinitionExpression("a"), new IntegerConstantExpression(4));
scope2.DefineVariable(new VariableDefinitionExpression("d"), new IntegerConstantExpression(5));
scope2.AddFunction(new FunctionDefinitionExpression("f1"));
var scope3 = new InterpreterScope();
scope3.DefineVariable(new VariableDefinitionExpression("b"), new IntegerConstantExpression(2));
scope3.DefineVariable(new VariableDefinitionExpression("c"), new IntegerConstantExpression(3));
var scope4 = new InterpreterScope();
scope4.AddFunction(new FunctionDefinitionExpression("f1"));
scope4.AddFunction(new FunctionDefinitionExpression("f2"));
var union = new InterpreterScope();
Assert.That(union.VariableCount, Is.EqualTo(0));
Assert.That(union.FunctionCount, Is.EqualTo(0));
union.Merge(scope1);
Assert.That(union.VariableCount, Is.EqualTo(1));
Assert.That(union.FunctionCount, Is.EqualTo(0));
union.Merge(scope2);
Assert.That(union.VariableCount, Is.EqualTo(2));
Assert.That(union.FunctionCount, Is.EqualTo(1));
Assert.That(union.GetVariable("a"), Is.EqualTo(new IntegerConstantExpression(4)));
union.Merge(scope3);
Assert.That(union.VariableCount, Is.EqualTo(4));
Assert.That(union.FunctionCount, Is.EqualTo(1));
union.Merge(scope4);
Assert.That(union.VariableCount, Is.EqualTo(4));
Assert.That(union.FunctionCount, Is.EqualTo(2));
}