[m-rev.] Bug in API documentation

[Volker Wysk]

Am Mittwoch, dem 12.11.2025 um 01:37 +1100 schrieb Zoltan Somogyi:
> 
> I am *guessing* that what Volker wants is to replace code like this:
> 
>   ( if multi_map.search(Map, Key, ValuesPrime) then
>     Values = ValuesPrime
>   else
>     Values = []
>   )
> 
> with a single call. It would be to a predicate that is still a search, not
> a lookup,
> but expresses the failure of the search not by failing, but by returning
> the empty list.

Your guess is right. 

In my case, having no occurrences of values for a given key is perfectly
okay. It doesn't mean failure. It should result in an empty list. 

I have a mapping from file names (last path component of each path) to the
full paths. There can be none, one or multiple such paths for such a file
name. When there are none, the result should be an empty list.

> This could work even in one_or_more_map: the output argument of this
> predicate would
> of course have to have type list(T), not one_or_more(T).
> 
> We could provide such a predicate in both modules. The tricky part is
> naming it.
> That is because your program would be more readable with the five lines of
> code above
> than with a single line of code containing a call to a predicate with a
> non-crystal-clear name.

If you want a crystal-clear name, it will be a long one. But what about
"occurrences" or maybe "occurs"?

Cheers
Volker