/// <summary>
/// Prepares locals corresponding to the variables of the declaration.
/// The locals are kept in a tree which captures the nesting of variables.
/// Each local is either a simple local (when its type is known) or a deconstruction local pending inference.
/// The caller is responsible for releasing the nested ArrayBuilders.
/// </summary>
private ArrayBuilder <DeconstructionVariable> BindDeconstructionDeclarationLocals(VariableComponentAssignmentSyntax node, TypeSyntax closestTypeSyntax, DiagnosticBag diagnostics)
{
var deconstructionVariable = BindDeconstructionDeclarationLocals(node.VariableComponent, diagnostics);
Debug.Assert(deconstructionVariable.HasNestedVariables);
return(deconstructionVariable.NestedVariables);
}
/// <summary>
/// Prepares locals corresponding to the variables of the declaration.
/// The locals are kept in a tree which captures the nesting of variables.
/// Each local is either a simple local (when its type is known) or a deconstruction local pending inference.
/// The caller is responsible for releasing the nested ArrayBuilders.
/// </summary>
private ArrayBuilder<DeconstructionVariable> BindDeconstructionDeclarationLocals(VariableComponentAssignmentSyntax node, TypeSyntax closestTypeSyntax, DiagnosticBag diagnostics)
{
var deconstructionVariable = BindDeconstructionDeclarationLocals(node.VariableComponent, diagnostics);
Debug.Assert(deconstructionVariable.HasNestedVariables);
return deconstructionVariable.NestedVariables;
}
private IEnumerable<TypeInferenceInfo> InferTypeInVariableComponentAssignment(
VariableComponentAssignmentSyntax variableComponentAssigment, ExpressionSyntax expression)
{
if (expression == variableComponentAssigment.Value)
{
var variableComponent = variableComponentAssigment.VariableComponent;
if (variableComponent.IsKind(SyntaxKind.TypedVariableComponent))
{
var typedVariable = (TypedVariableComponentSyntax)variableComponent;
return GetTypes(typedVariable.Type);
}
else if (variableComponent.IsKind(SyntaxKind.ParenthesizedVariableComponent))
{
// We have something of the form:
// (int a, int b) = ...
//
// This is a deconstruction, and a decent deconstructable type we can infer here
// is ValueTuple<int,int>.
var parenthesizedVariable = (ParenthesizedVariableComponentSyntax)variableComponent;
var tupleType = GetTupleType(parenthesizedVariable);
if (tupleType != null)
{
return SpecializedCollections.SingletonEnumerable(new TypeInferenceInfo(tupleType));
}
}
}
return SpecializedCollections.EmptyEnumerable<TypeInferenceInfo>();
}
