Add RDF.Resource.t type

CHANGELOG.md

@@ -11,6 +11,7 @@ This project adheres to [Semantic Versioning](http://semver.org/) and
 
 - `:implicit_base` option on the `RDF.Turtle.Encoder`
 - `:base_description` option on the `RDF.Turtle.Encoder`
+- `RDF.Resource.t` type
 - `RDF.Triple.coercible_t`, `RDF.Quad.coercible_t`, `RDF.Star.Triple.coercible_t`  
   and `RDF.Star.Quad.coercible_t` types
 

lib/rdf/resource.ex

@@ -0,0 +1,5 @@
+defmodule RDF.Resource do
+  alias RDF.{IRI, BlankNode}
+
+  @type t :: IRI.t() | BlankNode.t()
+end

lib/rdf/statement.ex

@@ -5,13 +5,13 @@ defmodule RDF.Statement do
   An RDF statement is either a `RDF.Triple` or a `RDF.Quad`.
   """
 
-  alias RDF.{BlankNode, IRI, Literal, Quad, Term, Triple, PropertyMap}
+  alias RDF.{Resource, BlankNode, IRI, Literal, Quad, Term, Triple, PropertyMap}
   import RDF.Guards
 
-  @type subject :: IRI.t() | BlankNode.t()
-  @type predicate :: IRI.t() | BlankNode.t()
-  @type object :: IRI.t() | BlankNode.t() | Literal.t()
-  @type graph_name :: IRI.t() | BlankNode.t() | nil
+  @type subject :: Resource.t()
+  @type predicate :: Resource.t()
+  @type object :: Resource.t() | Literal.t()
+  @type graph_name :: Resource.t() | nil
 
   @type coercible_subject :: subject | atom | String.t()
   @type coercible_predicate :: predicate | atom | String.t()

lib/rdf/term.ex

@@ -11,7 +11,7 @@ defprotocol RDF.Term do
   see <https://www.w3.org/TR/sparql11-query/#defn_RDFTerm>
   """
 
-  @type t :: RDF.IRI.t() | RDF.BlankNode.t() | RDF.Literal.t()
+  @type t :: RDF.Resource.t() | RDF.Literal.t()
 
   @doc """
   Checks if the given value is a RDF term.