Thu May 24 23:08:04 EDT 2018

Generic tracer works

  let log = do
        -- This is the compile time context.
        -- Compile a pseudo instruction that will query Time at run time.
        pseudo $ do
          -- This is the run time context.
          t <- loadm Time
          tell $ "sample: " ++ show t ++ "\n"

Now it is a bit confusing due to the compile time / run time

What his does is to insert a pseudo instruction in the stream with the
provided behavior.