private static BoundScope CreateParentScope(BoundGlobalScope previous)
{
// submission 3 -> submission 2 -> submission 1
// submission 1 -> submission 2 -> submission 3
var stack = new Stack <BoundGlobalScope>();
while (previous != null)
{
stack.Push(previous);
previous = previous.Previous;
}
BoundScope parent = null;
while (stack.Count > 0)
{
previous = stack.Pop();
var scope = new BoundScope(parent);
foreach (var variable in previous.Variables)
{
scope.TryDeclare(variable);
}
parent = scope;
}
return(parent);
}
private VariableSymbol BindVariable(SyntaxToken identifier, TypeSymbol type, bool isReadonly)
{
var name = identifier.Text ?? "?";
var declare = !identifier.IsMissing;
var variable = new VariableSymbol(name, isReadonly, type);
if (declare && !_scope.TryDeclare(variable))
{
if (isReadonly)
{
Diagnostics.ReportCannotAssign(identifier.Span, name);
}
else
{
Diagnostics.ReportVariableAlreadyDeclared(identifier.Span, name);
}
}
return(variable);
}