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 BoundStatement BindForStatement(ForStatementSyntax syntax)
{
var lowerBound = BindExpression(syntax.LowerBound, TypeSymbol.Int);
var upperBound = BindExpression(syntax.UpperBound, TypeSymbol.Int);
_scope = new BoundScope(_scope);
var variable = BindVariable(syntax.Identifier, TypeSymbol.Int, true);
var body = BindStatement(syntax.Body);
_scope = _scope.Parent;
return(new BoundForStatement(variable, lowerBound, upperBound, body));
}
private BoundStatement BindBlockStatement(BlockStatementSyntax syntax)
{
var statements = ImmutableArray.CreateBuilder <BoundStatement>();
_scope = new BoundScope(_scope);
foreach (var statementSyntax in syntax.Statements)
{
var statement = BindStatement(statementSyntax);
statements.Add(statement);
}
_scope = _scope.Parent;
return(new BoundBlockStatement(statements.ToImmutable()));
}
public BoundScope(BoundScope parent)
{
_variables = new Dictionary <string, VariableSymbol>();
Parent = parent;
}
private Binder(BoundScope parent)
{
Diagnostics = new DiagnosticsBag();
_scope = new BoundScope(parent);
}
