topic Re: Why does the explained syntax of the functions' arguments have the format: [,argument] (see example)? in QlikView

Why does the explained syntax of the functions' arguments have the format: [,argument] (see example)?

julioarriaga — Wed, 25 Nov 2020 16:16:04 GMT

I can't get my head around why this happens. Thanks in advance.

Re: Why does the explained syntax of the functions' arguments have the format: [,argument] (see example)?

swuehl — Tue, 21 Mar 2017 16:43:54 GMT

That's used to state an optional argument.

Re: Why does the explained syntax of the functions' arguments have the format: [,argument] (see example)?

Peter_Cammaert — Tue, 21 Mar 2017 16:45:24 GMT

Means that rank is optional, as the two examples demonstrate..

If you want to learn about the QlikView-specific BNF-syntax, read What is Backus-Naur formalism? ‒ QlikView

Re: Why does the explained syntax of the functions' arguments have the format: [,argument] (see example)?

swuehl — Tue, 21 Mar 2017 16:54:36 GMT

But I would agree that the Qlik implementation (edit: of BNF) could be sometimes confusing. For example

should [{SetExpression}] in

Min([{SetExpression}] [TOTAL [<fld {,fld}>]] expr [,rank])

be read as "the - optional - SetExpression can be repeated zero or more times"? Which is not true.

Re: Why does the explained syntax of the functions' arguments have the format: [,argument] (see example)?

Peter_Cammaert — Tue, 21 Mar 2017 17:02:05 GMT

In this case, the curly braces are not part of the BNF specification... More often than not, the QlikView documentation says that "...a set expression must be enclosed by braces..." which IMHO means that braces are required but they're not part of the set expression itself. They're just delimiters.

Documentation, you know...

Re: Why does the explained syntax of the functions' arguments have the format: [,argument] (see example)?

swuehl — Tue, 21 Mar 2017 17:03:33 GMT

Yeah, but then it should be printed BOLD?

All terminal symbols are printed in a bold face font. For example, "(" should be interpreted as a parenthesis defining precedence, whereas "(" should be interpreted as a character to be printed in the script.

But my eyes are weak, maybe they are in fact {} ...

Re: Why does the explained syntax of the functions' arguments have the format: [,argument] (see example)?

Peter_Cammaert — Tue, 21 Mar 2017 17:10:59 GMT

You're right. And no, you're eyes are ok.

This hasn't been corrected with respect to the exact same specification in the PDF-version of the manual. Like many other things. Shall we propose a friendly takeover of the documentaiton site?

Re: Why does the explained syntax of the functions' arguments have the format: [,argument] (see example)?

swuehl — Tue, 21 Mar 2017 19:23:31 GMT

This hasn't been corrected with respect to the exact same specification in the PDF-version of the manual. Like many other things. Shall we propose a friendly takeover of the documentaiton site?

Peter, I had some similar thoughts from time to time, like a community based, editable or commentable version of the HELP (maybe like a Wiki page or its comments section), the results of the discussion could then be feed back to the Official help from time to time by the Qlik officials.

There are still some errors in the HELP (though the Qlik functions haven't changed for years ) which should be fixed some day.