1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51
|
-- | Functions that help you with debugging.
-- Most would make sense in the Debug.Trace module.
module Debug.Util
(debug, debugM, debugMsg, debugMsgIf, ltrace, ltraceM, strace, traceId)
where
import Debug.Trace (trace)
-- | A version of Debug.Trace.trace that just prints a value.
-- This should be included in Debug.Trace
debug :: Show a => a -> a
debug = ltrace "DEBUG"
-- | A version of Debug.Trace.trace that just prints a value and a message.
-- This should be included in Debug.Trace
debugMsg :: Show a => String -> a -> a
debugMsg msg = ltrace ("DEBUG: " ++ msg)
-- | A version of Debug.Trace.trace that just prints a value and a message.
-- This should be included in Debug.Trace
debugMsgIf :: Show a => String -> (a -> Bool) -> a -> a
debugMsgIf msg cond x = if cond x then ltrace ("DEBUG: " ++ msg) x else x
-- | Monadic debug - like debug, but works as a standalone line in a monad.
--
-- TODO: TH version with error loaction info
debugM :: (Monad m, Show a) => a -> m a
debugM a = debug a `seq` return a
-- | Trace (print on stderr at runtime) a showable expression
-- like 'debug', but do not print \"DEBUG: \".
--
-- \"strace\" stands for \"show trace\".
strace :: Show a => a -> a
strace a = trace (show a) a
-- Alias for 'strace'.
--
-- \"traceId\" means it returns itself after tracing like the 'id' function.
traceId :: Show a => a -> a
traceId = strace
-- | Labelled trace - like 'strace', but with a label prepended.
ltrace :: Show a => String -> a -> a
ltrace l a = trace (l ++ ": " ++ show a) a
-- | Monadic debug - like debug, but works as a standalone line in a monad.
--
-- TODO: TH version with error loaction info
ltraceM :: (Monad m, Show a) => String -> a -> m a
ltraceM str a = ltrace str a `seq` return a
|