Invalid JSON-LD syntax

[hsolbrig]

The empty string ("") is not a valid JSON-LD key. See: https://w3c.github.io/json-ld-syntax/#terms.

https://github.com/prefixcommons/biocontext/blob/master/registry/monarch_context.jsonld as an example. The JSON-LD Playground can be used to test validity -- see: http://tinyurl.com/tvdm7qe for example of monarch issue.

Is the intent of the empty string to define the context for ':'?

[hsolbrig]

@micheldumontier or @cmungall -- can you respond to w3c/json-ld-api#379 (comment) ?