Re: [NTG-context] METAPOST vardef returning multiple and non-numeric types as a single answer?

Hola! So, the arguments passed to macros are by reference and not by value? I could have known of course, they are simple expansions, but I’d like to be sure. IfI assign to a variable inside a vardef macro and that variable is not ’save’d I’m changing the original? G

On 16 Mar 2020, at 09:31, Taco Hoekwater wrote:

...

On 15 Mar 2020, at 11:22, Gerben Wierda wrote:

I would like a vardef macro to return the pair of a picture and a bounding box. I don't want to use the setbound operator, because as soon as I do that, I cannot access the components of the picture anymore with pathpart.

I found metapost vardef returning multiple values on StackExchange but that is about returning multiple values of the same numeric type. Is it possible to have vardef return a set of (picture, path) or (picture, picture) in some way? If not, I need to make two vardef macros for each result type.

Sure, using that same endgroup,begingroup trick. But since there is no multi-assignment in metapost that doesn’t you help much. Either two separate vardefs or passing the to-be-assigned variable(s) as an extra argument(s) are generally more practical.

Best wishes, Taco

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