Add RDF.PrefixMap.drop/2

lib/rdf/prefix_map.ex

@@ -212,6 +212,26 @@ defmodule RDF.PrefixMap do
     delete(prefix_map, String.to_atom(prefix))
   end
 
+  @doc """
+  Drops the given `prefixes` from the given `prefix_map`.
+
+  If `prefixes` contains prefixes that are not in `prefix_map`, they're simply ignored.
+  """
+  def drop(prefix_map, prefixes)
+
+  def drop(%__MODULE__{map: map}, prefixes) do
+    %__MODULE__{
+      map:
+        Map.drop(
+          map,
+          Enum.map(prefixes, fn
+            prefix when is_binary(prefix) -> String.to_atom(prefix)
+            other -> other
+          end)
+        )
+    }
+  end
+
   @doc """
   Returns the namespace for the given prefix in the given `RDF.PrefixMap`.
 

test/unit/prefix_map_test.exs

@@ -208,6 +208,20 @@ defmodule RDF.PrefixMapTest do
     end
   end
 
+  describe "drop/2" do
+    test "when a mapping of the given prefix exists" do
+      assert PrefixMap.drop(@example3, [:ex3, :ex2, :ex]) == @example1
+    end
+
+    test "when no mapping of the given prefix exists" do
+      assert PrefixMap.drop(@example1, [:ex2]) == @example1
+    end
+
+    test "with the prefixes are given as strings" do
+      assert PrefixMap.drop(@example3, ["ex3", :ex2]) == @example1
+    end
+  end
+
   describe "namespace/2" do
     test "when a mapping of the given prefix exists" do
       assert PrefixMap.namespace(@example2, :ex2) == @ex_ns2