protobufs:int64_zigzag

int64_zigzag_when(?Original, ?Encoded) is det[private]

Convert between a signed integer value and its zigzag encoding, used for the protobuf sint32 and sint64 types. This is a low-level predicate; normally, you should use template_message/2 and the appropriate template term.

SWI-Prolog allows integer values greater than 64 bits, so a range check is done.

This predicate delays until either Original or Encoded is sufficiently instantiated.

There is also a non-delayed int64_zigzag/2

Arguments:

`Original`	- an integer in the original form
`Encoded`	- the zigzag encoding of `Original`

Errors

- Type,Domain if Original or Encoded are of the wrong type or out of range.

- instantiation error if both Original and Encoded are uninstantiated.