Refactor .reject.each and .reject.map to not allocate temporary array.

Author: jperville

lib/json/ld/api.rb

@@ -277,7 +277,9 @@ def self.flatten(input, context, options = {})
         create_node_map(value, graph_maps)
 
         default_graph = graph_maps['@default']
-        graph_maps.keys.kw_sort.reject {|k| k == '@default'}.each do |graph_name|
+        graph_maps.keys.kw_sort.each do |graph_name|
+          next if graph_name == '@default'
+
           graph = graph_maps[graph_name]
           entry = default_graph[graph_name] ||= {'@id' => graph_name}
           nodes = entry['@graph'] ||= []

lib/json/ld/context.rb

@@ -800,7 +800,7 @@ def from_vocabulary(graph)
       # Add term definitions for each class and property not in vocab, and
       # for those properties having an object range
       statements.each do |subject, values|
-        types = values.select {|v| v.predicate == RDF.type}.map(&:object)
+        types = values.each_with_object([]) { |v, memo| memo << v.object if v.predicate == RDF.type }
         is_property = types.any? {|t| t.to_s.include?("Property")}
 
         term = subject.to_s.split(/[\/\#]/).last

lib/json/ld/frame.rb

@@ -154,7 +154,9 @@ def frame(state, subjects, frame, **options)
         end
 
         # handle defaults in order
-        frame.keys.kw_sort.reject {|p| p.start_with?('@')}.each do |prop|
+        frame.keys.kw_sort.each do |prop|
+          next if prop.start_with?('@')
+
           # if omit default is off, then include default values for properties that appear in the next frame but are not in the matching subject
           n = frame[prop].first || {}
           omit_default_on = get_frame_flag(n, options, :omitDefault)