Don't compact things as relative IRIs that look like keywords.

Make sure that all keywords that are compacted use `vocab: true`.

Author: gkellogg

lib/json/ld/api.rb

@@ -311,7 +311,7 @@ def self.flatten(input, context, expanded: false, **options)
         if context && !flattened.empty?
           # Otherwise, return the result of compacting flattened according the Compaction algorithm passing context ensuring that the compaction result uses the @graph keyword (or its alias) at the top-level, even if the context is empty or if there is only one element to put in the @graph array. This ensures that the returned document has a deterministic structure.
           compacted = as_array(compact(flattened))
-          kwgraph = self.context.compact_iri('@graph')
+          kwgraph = self.context.compact_iri('@graph', vocab: true)
           flattened = self.context.
             serialize(provided_context: context).
             merge(kwgraph => compacted)
@@ -457,7 +457,7 @@ def self.frame(input, frame, expanded: false, **options)
         result = if !compacted.is_a?(Array)
           compacted
         else
-          kwgraph = context.compact_iri('@graph')
+          kwgraph = context.compact_iri('@graph', vocab: true)
           {kwgraph => compacted}
         end
         # Only add context if one was provided

lib/json/ld/compact.rb

@@ -145,7 +145,7 @@ def compact(element,
             end
 
             unless compacted_value.empty?
-              al = context.compact_iri('@reverse')
+              al = context.compact_iri('@reverse', vocab: true)
               log_debug("", depth: log_depth.to_i) {"remainder: #{al} => #{compacted_value.inspect}"}
               result[al] = compacted_value
             end

lib/json/ld/context.rb

@@ -1455,6 +1455,8 @@ def compact_iri(iri, base: nil, reverse: false, value: nil, vocab: nil)
       if !vocab
         # transform iri to a relative IRI using the document's base IRI
         iri = remove_base(self.base || base, iri)
+        # Make . relative if it has the form of a keyword.
+        iri = "./#{iri}" if iri.match?(/^@[a-zA-Z]+$/)
         return iri
       else
         return iri

spec/context_spec.rb

@@ -1148,7 +1148,6 @@ def containers
       "nil" => [nil, nil],
       "absolute IRI"  => ["http://example.com/", "http://example.com/"],
       "prefix:suffix" => ["ex:suffix",           "http://example.org/suffix"],
-      "keyword"       => ["@type",               "@type"],
       "unmapped"      => ["foo",                 "foo"],
       "bnode"         => [JSON::LD::JsonLdError:: IRIConfusedWithPrefix, RDF::Node("a")],
       "relative"      => ["foo/bar",             "http://base/foo/bar"],
@@ -1338,7 +1337,6 @@ def containers
         "nil" => [nil, nil],
         "absolute IRI"  => ["http://example.com/", "http://example.com/"],
         "prefix:suffix" => ["ex:suffix",           "http://example.org/suffix"],
-        "keyword"       => ["@type",               "@type"],
         "unmapped"      => ["foo",                 "foo"],
         "bnode"         => [JSON::LD::JsonLdError:: IRIConfusedWithPrefix, RDF::Node("a")],
         "relative"      => ["foo/bar",             "http://base/foo/bar"],