public IEnumerable <BsonValue> Execute(StringScanner s, LiteEngine engine)
{
var col = this.ReadCollection(engine, s);
// single document update
if (s.Match(@"\s*\{"))
{
var doc = JsonSerializer.Deserialize(s.ToString()).AsDocument;
s.ThrowIfNotFinish();
yield return(engine.Update(col, doc));
}
// query update
else
{
// db.colName.update
// field = value,
// array += valueToAdd,
// where _id = 1
// and ...
var query = Query.All();
var updates = new Update();
while (!s.HasTerminated)
{
var path = BsonExpression.ReadExpression(s, true, true).Source;
var action = s.Scan(@"\s*\+?=\s*").Trim().ThrowIfEmpty("Invalid operator (support = or +=)", s);
var value = this.ReadBsonValue(s);
var expr = value == null?BsonExpression.ReadExpression(s, true, false)?.Source : null;
if (action == "+=" && value != null)
{
updates.Add(path, value);
}
else if (action == "+=" && expr != null)
{
updates.AddExpr(path, expr);
}
else if (action == "=" && value != null)
{
updates.Set(path, value);
}
else if (action == "=" && expr != null)
{
updates.SetExpr(path, expr);
}
else
{
throw LiteException.SyntaxError(s);
}
s.Scan(@"\s*");
if (s.Scan(@",\s*").Length > 0)
{
continue;
}
else if (s.Scan(@"where\s*").Length > 0 || s.HasTerminated)
{
break;
}
else
{
throw LiteException.SyntaxError(s);
}
}
if (!s.HasTerminated)
{
query = this.ReadQuery(s, false);
}
s.ThrowIfNotFinish();
yield return(engine.Update(col, query, updates));
}
}