private static BoundScope CreateParentScope(BoundGlobalScope previous)
{
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 v in previous.Variables)
{
scope.TryDeclare(v);
}
parent = scope;
}
return(parent);
}
private BoundStatement BindVariableDeclaration(VariableDeclarationSyntax syntax)
{
var name = syntax.Identifier.Text;
var isReadOnly = syntax.Keyword.Kind == SyntaxKind.LetKeyword;
var expression = BindExpression(syntax.Initializer);
var variable = new VariableSymbol(name, isReadOnly, expression.Type);
if (!_scope.TryDeclare(variable))
{
_diagnostics.ReportVariableAlreadyDeclared(syntax.Identifier.Span, name);
}
return(new BoundVariableDeclaration(variable, expression));
}
private BoundStatement BindForStatement(ForStatementSyntax syntax)
{
var name = syntax.Identifier.Text;
var variable = new VariableSymbol(name, true, typeof(int));
_scope = new BoundScope(_scope);
if (!_scope.TryDeclare(variable))
{
_diagnostics.ReportVariableAlreadyDeclared(syntax.Identifier.Span, name);
}
var lowerBound = BindExpression(syntax.LowerBound, typeof(int));
var upperBound = BindExpression(syntax.UpperBound, typeof(int));
var body = BindStatement(syntax.Body);
_scope = _scope.Parent;
return(new BoundForStatement(variable, lowerBound, upperBound, body));
}
