@hackage error-location0.1.5.2

Error functions that give file location information

$(err "OH NO!")

main:Main main.hs:16:1 OH NO!

Notice how it displays package:module file:line:character It exposes the functions err (error), undef (undefined), and trc (Debug.Trace.trace). All of these behave the same as their normal counterpart but also spit out a location.

I also included my favorite helper, debug, which is like trace but just show the value.

debug [1,2,3]

DEBUG: [1,2,3]
[1,2,3]

And The Template Haskell version.

$(dbg) [1,2,3]

DEBUG main:Main main.hs:1:3 [1,2,3]
[1,2,3]

See module for a listing of all the functions with short descriptions, and the homepage for some more examples https://github.com/gregwebs/ErrorLocation.hs