protected override Expression VisitBinary(BinaryExpression binary)
{
if ((binary.NodeType == ExpressionType.Assign) &&
(binary.Left.NodeType == ExpressionType.Parameter) &&
!JoinedAssignedVariables.Contains(binary.Left) &&
!_assignedAssignments.Contains(binary))
{
var variable = (ParameterExpression)binary.Left;
if (VariableHasNotYetBeenAccessed(variable))
{
if (_constructs.Any())
{
_constructsByAssignment.Add(binary, _constructs.Peek());
}
JoinedAssignments.Add(binary);
_accessedVariables.Add(variable);
JoinedAssignedVariables.Add(variable);
}
AddAssignmentIfAppropriate(binary.Right);
}
return(base.VisitBinary(binary));
}
protected override Expression VisitParameter(ParameterExpression variable)
{
if (VariableHasNotYetBeenAccessed(variable))
{
_accessedVariables.Add(variable);
}
if (!JoinedAssignedVariables.Contains(variable))
{
return(base.VisitParameter(variable));
}
var joinedAssignmentData = _constructsByAssignment
.Where(kvp => kvp.Key.Left == variable)
.Select(kvp => new
{
Assignment = kvp.Key,
Construct = kvp.Value
})
.FirstOrDefault();
if ((joinedAssignmentData == null) || _constructs.Contains(joinedAssignmentData.Construct))
{
return(base.VisitParameter(variable));
}
// This variable was assigned within a construct but is being accessed
// outside of that scope, so the assignment shouldn't be joined:
JoinedAssignedVariables.Remove(variable);
JoinedAssignments.Remove(joinedAssignmentData.Assignment);
_constructsByAssignment.Remove(joinedAssignmentData.Assignment);
return(base.VisitParameter(variable));
}
