/// <summary>
/// Decodes an LNode as a type definition.
/// </summary>
/// <param name="node">The node to decode.</param>
/// <param name="state">The decoder's state.</param>
/// <returns>A decoded type.</returns>
public static IrType Decode(LNode node, DecoderState state)
{
QualifiedName name;
if (!FeedbackHelpers.AssertArgCount(node, 4, state.Log) ||
!state.AssertDecodeQualifiedName(node.Args[0], out name))
{
return(null);
}
else if (node.Calls(TypeParameterDefinitionSymbol))
{
return(new IrGenericParameter(node, state));
}
else if (node.Calls(TypeDefinitionSymbol))
{
return(new IrType(node, state));
}
else
{
state.Log.LogSyntaxError(
node,
FeedbackHelpers.QuoteEven(
"expected ",
TypeDefinitionSymbol.Name,
" or ",
TypeParameterDefinitionSymbol.Name,
"."));
return(null);
}
}
/// <summary>
/// Decodes an assembly from an LNode.
/// </summary>
/// <param name="data">The LNode to decode.</param>
/// <param name="state">The decoder to use.</param>
/// <returns>
/// A decoded assembly if the node can be decoded;
/// otherwise, <c>null</c>.
/// </returns>
public static IrAssembly Decode(LNode data, DecoderState state)
{
QualifiedName name;
if (!FeedbackHelpers.AssertArgCount(data, 2, state.Log) ||
!state.AssertDecodeQualifiedName(data.Args[0], out name))
{
return(null);
}
else
{
return(new IrAssembly(data, state));
}
}
/// <inheritdoc/>
public override IType Decode(LNode data, DecoderState state)
{
if (data.Calls(pointerSymbol))
{
if (!FeedbackHelpers.AssertArgCount(data, 2, state.Log))
{
return(ErrorType.Instance);
}
var elemType = state.DecodeType(data.Args[0]);
PointerKind kind;
if (AssertDecodePointerKind(data.Args[1], state, out kind))
{
return(elemType.MakePointerType(kind));
}
else
{
return(ErrorType.Instance);
}
}
else if (data.Calls(genericParameterSymbol))
{
if (!FeedbackHelpers.AssertArgCount(data, 2, state.Log))
{
return(ErrorType.Instance);
}
IGenericMember parent;
SimpleName name;
if (state.AssertDecodeGenericMember(data.Args[0], out parent) &&
state.AssertDecodeSimpleName(data.Args[1], out name))
{
var types = state.TypeResolver.ResolveGenericParameters(parent, name);
if (AssertSingleChildType(types, data, state, "generic declaration"))
{
return(types[0]);
}
}
return(ErrorType.Instance);
}
else if (data.Calls(CodeSymbols.Of))
{
if (!FeedbackHelpers.AssertMinArgCount(data, 2, state.Log))
{
return(ErrorType.Instance);
}
var genericDecl = state.DecodeType(data.Args[0]);
var genericArgs = data.Args.Slice(1).EagerSelect <LNode, IType>(state.DecodeType);
int count = genericDecl.GenericParameters.Count;
if (count != genericArgs.Count)
{
FeedbackHelpers.LogSyntaxError(
state.Log,
data,
FeedbackHelpers.QuoteEven(
"type ",
FeedbackHelpers.Print(data.Args[0]),
" is instantiated with ",
genericArgs.Count.ToString(),
" arguments but has only ",
count.ToString(),
" parameters."));
return(ErrorType.Instance);
}
return(genericDecl.MakeGenericType(genericArgs));
}
else if (data.Calls(CodeSymbols.Dot))
{
if (!FeedbackHelpers.AssertArgCount(data, 2, state.Log))
{
return(ErrorType.Instance);
}
SimpleName childName;
if (!state.AssertDecodeSimpleName(data.Args[1], out childName))
{
return(ErrorType.Instance);
}
var parentType = state.DecodeType(data.Args[0]);
if (parentType == ErrorType.Instance)
{
// Make sure that we don't log an additional error
// just because the parent type was wrong.
return(ErrorType.Instance);
}
var childTypes = state.TypeResolver.ResolveNestedTypes(parentType, childName);
if (AssertSingleChildType(childTypes, data, state, "type"))
{
return(childTypes[0]);
}
else
{
return(ErrorType.Instance);
}
}
else
{
QualifiedName fullName;
if (state.AssertDecodeQualifiedName(data, out fullName))
{
var types = state.TypeResolver.ResolveTypes(fullName);
if (AssertSingleGlobalType(types, data, state))
{
return(types[0]);
}
else
{
return(ErrorType.Instance);
}
}
else
{
return(ErrorType.Instance);
}
}
}
