/// <summary>
/// Registers an item for usage in a particular direction
/// </summary>
/// <param name="scope">The scope to use</param>
/// <param name="item">The item to register</param>
/// <param name="direction">The direction to register</param>
/// <param name="sourceExpr">The source expression used for error messages</param>
public void RegisterItemUsageDirection(Instance.IParameterizedInstance scope, object item, ItemUsageDirection direction, AST.ParsedItem sourceExpr)
{
if (scope == null)
{
throw new ArgumentNullException(nameof(scope));
}
if (item == null)
{
throw new ArgumentNullException(nameof(item));
}
if (!ItemDirection.TryGetValue(scope, out var usagescope))
{
ItemDirection[scope] = usagescope = new Dictionary <object, ItemUsageDirection>();
}
if (item is Instance.Signal signalInstance)
{
// Get list of parameters with direction from instantiation
var directionParam = scope
.MappedParameters
.Zip(
Enumerable.Range(0, scope.MappedParameters.Count),
(x, i) => new
{
Direction = scope.SourceParameters[i].Direction,
Bus = x.MappedItem
}
)
.Where(x => x.Bus == signalInstance.ParentBus)
.FirstOrDefault();
// Local bus is bi-directional and does not need checking
if (directionParam != null)
{
var definedDirection = directionParam.Direction;
// Flip the signal if it has inverse direction
if (signalInstance.Source.Direction == SignalDirection.Inverse)
{
definedDirection =
definedDirection == ParameterDirection.In
? ParameterDirection.Out
: ParameterDirection.In;
}
if (definedDirection == ParameterDirection.Out && direction != ItemUsageDirection.Write)
{
throw new ParserException($"Can only write to output signal: {signalInstance.Name}", sourceExpr);
}
if (definedDirection == ParameterDirection.In && direction != ItemUsageDirection.Read)
{
throw new ParserException($"Can only read from input signal: {signalInstance.Name}", sourceExpr);
}
}
}
if (!usagescope.TryGetValue(item, out var d))
{
usagescope[item] = direction;
}
else if (d != direction)
{
usagescope[item] = ItemUsageDirection.Both;
}
}
/// <summary>
/// Tries to add a new symbol to the table and throws an exception pointing to the offending location
/// </summary>
/// <param name="name">The name of the item to add</param>
/// <param name="item">The item to add</param>
/// <param name="token">The token used in the error message</param>
public void TryAddSymbol(string name, object item, AST.ParsedItem token)
{
TryAddSymbol(name, item, token.SourceToken);
}