RFC: Allow language Tag support in GraphQL

Users GraphQL
14

Using this feature or any of the described combinations from language-support with IRIs as a predicate name fails for me with a parsing error.

version: v23.1
running on Docker
GraphQL Endpoint: http(s)://{host}:{port}/admin/schema

Steps to reproduce:

Trying to deploy a GraphQL schema with:

type Concept implements Thing {    
    prefLabel: String @dgraph(pred: "<http://www.w3.org/2004/02/skos/core#prefLabel>@.")
    ...
}

results in:

{"errors":[{"message":"resolving updateGQLSchema failed because line xxx column xx: Missing colon in type declaration. Got @ (Locations: [{Line: 3, Column: 4}])","extensions":{"code":"Error"}}]}

Using it without, succeeds but delivers no results, as in my case there are only tagged strings.

type Concept implements Thing {    
    prefLabel: String @dgraph(pred: "<http://www.w3.org/2004/02/skos/core#prefLabel>")
    ...
}

{"data":{"code":"Success","message":"Done"}}

Is there a way to overcome this issue within the GraphQL generator?

I have chosen Dgraph for my use-case because of the mentioned support for IRIs predicate names and the ability to map those into a GraphQL API through @dgraph directive.