PR to #21

[flrdv]

renamed walker closure's named return value to exit instead of err, as considered in #21

[flrdv]

It would make sense to update the documentation as well by adding the following sentence where relevant:

If fn returns true, <FuncName> immediately stops and returns ErrorCodeCallback.

Should those be in docstrings or distributed across the code by itself?

[romshark]

Should those be in docstrings or distributed across the code by itself?

In the doc comments of the individual functions/methods, like:

// ScanOne calls fn for every encountered value including objects and arrays.
// When an object or array is encountered fn will also be called for each of its
// member and element values.
// If fn returns true, ScanOne immediately stops and returns ErrorCodeCallback.
//
// ...

[flrdv]

Any updates?