Nice to meet you, GHC Developers! I'm new to contributing to GHC. Today let me suggest new APIs of the Debug.Trace http://hackage.haskell.org/package/base-4.11.1.0/docs/Debug-Trace.html module, named: - taggedTraceShowId :: Show a => String -> a -> a - taggedTraceWith :: (a -> String) -> String -> a -> a These are inspired by Elm's Debug.log http://package.elm-lang.org/packages/elm-lang/core/5.1.1/Debug#log function. The prefix "tagged" is named after its argument https://github.com/elm-lang/core/blob/5.1.1/src/Native/Debug.js#L5. I mean, these new APIs prepend a string as a tag to the output by traceShowId etc. It helps us recognize what the printed values stand for. I frequently want such functions and write them manually or copy-and-paste from the Debug.TraceUtils. I'm tired of that. That's why I made this suggestion. *Comparison with the existing solution* - Debug.TraceUtils http://hackage.haskell.org/package/TraceUtils-0.1.0.2/docs/Debug-TraceUtils.... : - Essentially, this suggestion is to add APIs already implemented by TraceUtils. - As the document of TraceUtils suggests, we can copy and paste the functions from its source, but it's still tiresome. - Combine Debug.Trace.traceShowId with Debug.Trace.trace: - e.g. trace "Tag" $ traceShowId x - A bit hard to type. - trace always prints a newline, which makes it difficult to tell the tags from the printed value. After receiving some feedback here, I'm going to submit to https://github.com/ghc-proposals/ghc-proposals Thanks in advance! -- Yuji Yamamoto twitter: @igrep GitHub: https://github.com/igrep GitLab: https://gitlab.com/igrep Facebook: http://www.facebook.com/igrep Google+: https://plus.google.com/u/0/+YujiYamamoto_igrep