A utility module to make troubleshooting problems by tracing Gradualizer internals more efficient. Configuration of this module is compile time, but using the tracing facilities is more efficient than traditional printf-debugging anyway.

Together with the shell interface of gradualizer, we can use this module to inspect or debug the inner workings of the type checker live. Watch out for the trace sizes - they can grow huge!

  > gradualizer_tracer:start().
  ok
  > gradualizer:type_of("[a]").
  {trace,<0.1296.0>,call,
         {typechecker,type_check_expr,[{venv,#{}},{cons,1,{atom,1,a},{nil,1}}]}}
  {trace,<0.1296.0>,call,{typechecker,type_check_expr,[{venv,#{}},{atom,1,a}]}}
  {trace,<0.1296.0>,return_from,
         {typechecker,type_check_expr,2},
         {{atom,0,a},{venv,#{}},{constraints,#{},#{},#{}}}}
  {trace,<0.1296.0>,return_to,{typechecker,do_type_check_expr,2}}
  {trace,<0.1296.0>,call,{typechecker,type_check_expr,[{venv,#{}},{nil,1}]}}
  {trace,<0.1296.0>,return_from,
         {typechecker,type_check_expr,2},
         {{type,0,nil,[]},{venv,#{}},{constraints,#{},#{},#{}}}}
  {trace,<0.1296.0>,return_to,{typechecker,do_type_check_expr,2}}
  {trace,<0.1296.0>,return_from,
         {typechecker,type_check_expr,2},
         {{type,0,nonempty_list,[{atom,0,a}]},
          {venv,#{}},
          {constraints,#{},#{},#{}}}}
  {trace,<0.1296.0>,return_to,{g,type_of,2}}
  {type,0,nonempty_list,[{atom,0,a}]}