@hackage print-debugger0.0

Print debugging with stack trace for Haskell (formatted for the IDE).

HaskellPrintDebugger

Prints lines with IDE friendly stack traces in Haskell.


Example:

debugTraceIO "foobar"

foobar in thread "1" :

    at Main.call(Main.hs:41)

See screenshot: http://i.imgur.com/KCXYHNk.png


Instructions:

  1. Add the file "StackTraceDebug.hs" to your Haskell project.
  2. Add "import StackTraceDebug" if you want to call the function
  3. Call "debugTraceIO" with any String argument.
  4. When you are done, remove or comment out all calls to debugTraceIO.
  5. Optionally, set value "debugMode" to "False" in "StackTraceDebug.hs" to mute all calls to "debugTraceIO".

Benefits:

  • Does not require to be compiled with "-prof"
  • Easier to locate your print statements
  • Location of print statement can be highlighted in an IDE
  • Easy to turn print statemments on/off without having to manually uncomment each one.
  • Public Domain

Requirements:

  • GHC 7.10.1 (or greater)
  • "-XImplicitParams" compiler option
  • "split" package or addition of ", split" to "build-depends" line in ".cabal" file

Configuration:

Sample ".cabal" file:

name: HaskellProject1

version: 1.0

Build-Type: Simple

cabal-version: >= 1.2

executable HaskellProject1

main-is: Main.hs

hs-source-dirs: src

build-depends: base, split

Sample compilation:

    $> ghc StackTraceDebug.hs -Wall -Werror -XImplicitParams


Know bugs:

http://stackoverflow.com/questions/35354153/haskell-cannot-import-ghc-srcloc

^ Doesn't build correctly on Caball Ubuntu 14.04 with old (ubuntu LTS repo) version of GHC.

(but compiles fine on Windows with "ghc StackTraceDebug.hs -Wall -Werror -XImplicitParams")

To report or pinpoint bugs, email johnmichaelreedfas@gmail.com