Custom Function are great, but it's infuriating that if you've a multi-file solution, you have to re)create the CF you want to use in every file where it's needed. It's a nightmare for code maintenance and a terrible waste of time.
So this proposed calc function would just call the CF from another file to be executed in the current file, as if the CF was created in that current file.
This would allow us to have one file as the custom function repository.
So if we have a WorkingHour(time) CF in fileA that returns one if the passed time is a working hour.
Then from fileB we would write in hours calcs :
Of course ideally this could be done by a modification of the current CF calling method. A non declared final parameter could be used to pass the filename like :
WorkingHour(time;"fileA") rather than failing, filemaker would consider that extra parameter as the filename where resides the CF
Or it could use a special reserved parameter name like
Of course some badly created CF that depends on fields of the file they reside in won't work with that call, but that's a very few percentage of all existing CF, and ideal they shouldn't exist anyway.