It is quite a late answer for you but, Deluge does not natively support while loops. that is why it is expecting you to close the line of code but instead it gets a curly brace.

see [this link][1] to elaborate on how you could create a for each loop to act like a while loop.

[1]: https://functiondynamic.com/knowledge-base/zoho-deluge-while-loops/#:~:text=Though%20Zoho%20deluge%20doesn't,one%20that%20we%20often%20use).