private Expression GetControlExpression(int node, Dictionary <int, bool> visited)
{
if (visited.ContainsKey(node) && visited[node])
{
throw new InvalidGraphException("Infinite flow loop");
}
visited[node] = true;
var currentNode = GetNode(node);
var inputDataExpressions = new Expression[currentNode.Inputs.Length];
var outputFlowExpressions = new Expression[currentNode.Outputs.Length];
// ASSUMPTION: first input socket is a flow socket, the rest are data sockets
for (int i = 1; i < currentNode.Inputs.Length; i++)
{
var connection = currentNode.Inputs[i][0];
if (connection == null)
{
inputDataExpressions[i] = GetDefaultValueOfEmptyInput(currentNode.Type, i, currentNode.Data.Value);
}
else
{
inputDataExpressions[i] = GetDataExpression(node, i);
}
}
for (int i = 0; i < currentNode.Outputs.Length; i++)
{
var connection = currentNode.Outputs[i][0];
if (connection != null && !FunctionsFacade.IsPureFunction(GetNode(connection.Node).Type))
{
outputFlowExpressions[i] = GetControlExpression(connection.Node, visited);
}
else
{
outputFlowExpressions[i] = Expression.Empty();
}
}
visited[node] = false;
switch (currentNode.Type)
{
case FunctionNames.If:
return(Expression.IfThenElse(
Expression.Convert(inputDataExpressions.ElementAtOrDefault(1), typeof(bool)),
outputFlowExpressions.ElementAtOrDefault(0),
outputFlowExpressions.ElementAtOrDefault(1)
));
case FunctionNames.ForEach:
return(Expression.Block(
ExpressionUtils.ForEach(
inputDataExpressions.ElementAtOrDefault(1),
LoopVars[Tuple.Create(node, 1)],
outputFlowExpressions.ElementAtOrDefault(0)
),
outputFlowExpressions.ElementAtOrDefault(3)
));
case FunctionNames.For:
throw new NotImplementedException();
case FunctionNames.While:
throw new NotImplementedException();
case FunctionNames.Return:
return(Expression.Return(ReturnTarget, inputDataExpressions.ElementAtOrDefault(1)));
case FunctionNames.Set:
return(Expression.Block(
Expression.Assign(LocalVars[currentNode.Data.Value], inputDataExpressions.ElementAtOrDefault(1)),
outputFlowExpressions[0]
));
default:
throw new InvalidGraphException("Not a control function or is entry");
}
}
