Comment by jimmygrapes

IIRC even QuickBASIC 4.5 had a form of "IntelliSense" in the form of hints as to the defined data structure, if provided in DECLARE statements. F1 hints are mentioned elsewhere for built-ins but I seem to recall it (or a similar quick action) also working for a smart of "what kind of data are you allowed to pass to this user defined subroutine or function".