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Hi,

i would try something like:




Hope it helps,
Tuur

Hi )

As far as I understand it 'calc()' (without semicolon) is a 'parameter in action' while 'calc();' is an action. You can use first one inside comparisons.

see this line in documentation:

The calc(expression) action is a special action that can be only used as parameter when calling other actions or when accessing array elements.



Therefore, 'if(A GT calc(B - 10), do_smth();); is OK and 'if(A GT calc(B - 10); , do_smth(); );' might throw an error.


Or like this one:


set(A, calc(B - 10));
or shorter would be:
calc(A, B - 10);

yes calc() is a special case.
i remember mails w klaus about this, but forgot the rules .-)

calc(expression) differs from calc(dest, expession)
the first one is used in comparisons or instead of get() for example
for the latter you need a semicolon in some cases.

in this example its not obvious to me, too
why calc() doesn't recognize its 2 arguments and tries to evaluate both as one expression

Seems it's impossible to use calc() without semicolon and WITH destination variable:



First two traces work the same, while the third one fails.

trace(calc(dest, 'test' + '_me')); => trace(calc(dest + 'test' + '_me'));

if(true, calc(test,5+3)); --> test = null
if(true, calc(test,5+3);); --> test = 8

you need the semicolon, the question is why :)
my bet is, internally 2 separate functions, one has 1 parameter, one has 2 parameters

Hi,

right, there are two different 'calc' cases:

- one is a normal action call


- and the other is special case to evalute an expression before passing its result to an action:


I have tried showing that also here in the documentation:
https://krpano.com/docu/actions/#calc

That parser of the action calls doesn't know it in advance if an action might get a callback string or just a normal parameter and because the parameters are type-less it can't differ between action-calls and strings. And further the parsing of the given parameters of an action happens in a later parsing step, so it can't count the number of the parameters in advance to differ between both cases.

That means an action( calc(...) ) call always results in the second case, but when ending the calc with ';' or adding other actions to the call, it is not longer a valid get/calc parameter call and the parameters is handled as normal string parameter.

That also means a calc(dest, expression) doesn't 'always' requires a terminating semicolon, but it would require one, when using that in a parameter of another action call.

I will try adding that case a special note in the documentation.

Best regards,
Klaus

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