// Block
private Result RewriteBlockExpression(Expression expr, Stack stack)
{
BlockExpression node = (BlockExpression)expr;
int count = node.ExpressionCount();
RewriteAction action = RewriteAction.None;
Expression[] clone = null;
for (int i = 0; i < count; i++)
{
Expression expression = node.GetExpression(i);
// All statements within the block execute at the
// same stack state.
Result rewritten = RewriteExpression(expression, stack);
action |= rewritten.Action;
if (clone == null && rewritten.Action != RewriteAction.None)
{
clone = Clone(node.Expressions, i);
}
if (clone != null)
{
clone[i] = rewritten.Node;
}
}
if (action != RewriteAction.None)
{
// okay to wrap since we know no one can mutate the clone array
expr = node.Rewrite(null, clone);
}
return(new Result(action, expr));
}
