refactor: delete a less meaningful file

Author: mame

lib/typeprof/core.rb

@@ -23,7 +23,6 @@
 require_relative "core/env/value_entity"
 require_relative "core/env/method"
 require_relative "core/env/static_read"
-require_relative "core/graph"
 require_relative "core/graph/change_set"
 require_relative "core/graph/vertex"
 require_relative "core/graph/filter"

lib/typeprof/core/graph.rb

@@ -42,6 +42,7 @@ def check_match(genv, changes, vtx)
     end
 
     def show
+      Fiber[:show_rec] ||= Set[]
       if Fiber[:show_rec].include?(self)
         "untyped"
       else
@@ -117,6 +118,7 @@ def remove_edge(genv, nvtx)
     end
 
     def show
+      Fiber[:show_rec] ||= Set[]
       if Fiber[:show_rec].include?(self)
         "...(recursive)..."
       else