úÎ ¼0like Prelude.error, but gives the file location  $(err "OH NO!)  main:Main main.hs:4:10 OH NO! 4like Prelude.undefined, but gives the file location # use trace to output the location. : this way we still use undefined instead of calling error  $(undef) " main:Main main.hs:4:10 undefined  err: Prelude.undefined 9A version of Debug.Trace.trace that just prints a value. ( This should be included in Debug.Trace CA TH version of Debug.Trace.trace that prints location information $ TODO: make a debug version of this error-location-0.1.3 ErrorLocationerrundefdebugtrclocationToString