Empty frame [] should not destroy triples

I'm not sure if this is a bug, a design decision, or the unintended
but necessary consequence of a design decision... but I realized that
part of what makes it difficult for me to construct useful frames is
the behavior of am empty array frame:  [].

As far as I'm concerned, an empty frame ought to preserve the triples
in the input graph. But the current behavior is more subtle:  when a
predicate has multiple URI objects, sometimes these objects are not
preserved in the output.  Here's the simplest case I can construct
that demonstrates the issue:

1.  Input asserts three URI nodes:  a "looker" which canSee "spotted"
and "forgotten".   Input also re-asserts that "spotted" exists.
2.  Frame is [].
3.  Output loses this triple:  <looker> <canSee> <forgotten>.

    "@subject": [{
        "@subject": "looker",
        "canSee": [{
            "@iri": "forgotten"
        }, {
            "@iri": "spotted"
    }, {
        "@subject": "spotted"


OUTPUT (where's "forgotten"?)
    "@subject": {
        "@iri": "looker"
    "canSee": {
        "@iri": "spotted"
}, {
    "@subject": {
        "@iri": "spotted"

The thing that's really giving me grief is probably a downstream
consequence of this behavior.  But I figured I'd start at the root of
the problem. Is the behavior known, understood, or intended?

Thanks again,


Received on Wednesday, 23 November 2011 14:51:55 UTC