Support Unicode signs when parsing usage info

In some terms (notably Japanese ones) full-width sings are used instead
of regular '<' and '>' when denoting usage info.

lib/iev/termbase/term_attrs_parser.rb

@@ -92,10 +92,17 @@ def extract_part_of_speech(str)
       end
 
       def extract_usage_info(str)
-        info_rx = /<(.*?)>/
+        info_rx = %r{
+          # regular ASCII less and greater than signs
+          < (?<inner>.*?) >
+          |
+          # ＜ and ＞, i.e. full-width less and greater than signs
+          # which are used instead of ASCII signs in some CJK terms
+          \uFF1C (?<inner>.*?) \uFF1E
+        }x.freeze
 
         remove_from_string(str, info_rx) do |md|
-          @usage_info = md[1].strip
+          @usage_info = md[:inner].strip
         end
       end
 

spec/iev/termbase/term_attrs_parser_spec.rb

@@ -157,6 +157,15 @@
       string: "a whatever" do
       expect(subject.usage_info).to be(nil)
     end
+
+    it "supports full-width signs", string: "a string \uFF1Cinfo\uFF1E" do
+      expect(subject.usage_info).to eq("info")
+    end
+
+    it "disallows mixing regular and full-width signs",
+      string: "a string \uFF1Cinfo>" do
+      expect(subject.usage_info).to be(nil)
+    end
   end
 
   describe "geographical area" do