247 lines
		
	
	
		
			9.3 KiB
		
	
	
	
		
			Haskell
		
	
	
	
	
	
			
		
		
	
	
			247 lines
		
	
	
		
			9.3 KiB
		
	
	
	
		
			Haskell
		
	
	
	
	
	
{-# LANGUAGE CPP, FlexibleContexts, TypeFamilies #-}
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-- | Debugging helpers
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-- more:
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-- http://hackage.haskell.org/packages/archive/TraceUtils/0.1.0.2/doc/html/Debug-TraceUtils.html
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-- http://hackage.haskell.org/packages/archive/trace-call/0.1/doc/html/Debug-TraceCall.html
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-- http://hackage.haskell.org/packages/archive/htrace/0.1/doc/html/Debug-HTrace.html
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-- http://hackage.haskell.org/packages/archive/traced/2009.7.20/doc/html/Debug-Traced.html
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module Hledger.Utils.Debug (
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  module Hledger.Utils.Debug
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  ,module Debug.Trace
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  ,ppShow
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)
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where
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import           Control.Monad (when)
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import           Control.Monad.IO.Class
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import           Data.List hiding (uncons)
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import qualified Data.Text as T
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import           Debug.Trace
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import           Hledger.Utils.Parse
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import           Safe (readDef)
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import           System.Environment (getArgs)
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import           System.Exit
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import           System.IO.Unsafe (unsafePerformIO)
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import           Text.Megaparsec
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import           Text.Printf
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import           Text.Show.Pretty (ppShow)
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pprint :: Show a => a -> IO ()
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pprint = putStrLn . ppShow
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-- | Trace (print to stderr) a showable value using a custom show function.
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traceWith :: (a -> String) -> a -> a
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traceWith f a = trace (f a) a
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-- | Parsec trace - show the current parsec position and next input,
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-- and the provided label if it's non-null.
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ptrace :: String -> TextParser m ()
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ptrace msg = do
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  pos <- getPosition
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  next <- (T.take peeklength) `fmap` getInput
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  let (l,c) = (sourceLine pos, sourceColumn pos)
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      s  = printf "at line %2d col %2d: %s" (unPos l) (unPos c) (show next) :: String
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      s' = printf ("%-"++show (peeklength+30)++"s") s ++ " " ++ msg
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  trace s' $ return ()
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  where
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    peeklength = 30
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-- | Global debug level, which controls the verbosity of debug output
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-- on the console. The default is 0 meaning no debug output. The
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-- @--debug@ command line flag sets it to 1, or @--debug=N@ sets it to
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-- a higher value (note: not @--debug N@ for some reason).  This uses
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-- unsafePerformIO and can be accessed from anywhere and before normal
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-- command-line processing. When running with :main in GHCI, you must
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-- touch and reload this module to see the effect of a new --debug option.
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-- After command-line processing, it is also available as the @debug_@
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-- field of 'Hledger.Cli.CliOptions.CliOpts'.
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-- {-# OPTIONS_GHC -fno-cse #-} 
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-- {-# NOINLINE debugLevel #-}
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debugLevel :: Int
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debugLevel = case snd $ break (=="--debug") args of
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               "--debug":[]  -> 1
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               "--debug":n:_ -> readDef 1 n
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               _             ->
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                 case take 1 $ filter ("--debug" `isPrefixOf`) args of
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                   ['-':'-':'d':'e':'b':'u':'g':'=':v] -> readDef 1 v
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                   _                                   -> 0
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    where
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      args = unsafePerformIO getArgs
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-- | Convenience aliases for tracePrettyAt.
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-- Always pretty-print a message and the showable value to the console, then return it.
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-- ("dbg" without the 0 clashes with megaparsec 5.1).
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dbg0 :: Show a => String -> a -> a
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dbg0 = tracePrettyAt 0
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-- | Pretty-print a message and the showable value to the console when the debug level is >= 1, then return it. Uses unsafePerformIO.
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dbg1 :: Show a => String -> a -> a
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dbg1 = tracePrettyAt 1
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dbg2 :: Show a => String -> a -> a
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dbg2 = tracePrettyAt 2
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dbg3 :: Show a => String -> a -> a
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dbg3 = tracePrettyAt 3
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dbg4 :: Show a => String -> a -> a
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dbg4 = tracePrettyAt 4
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dbg5 :: Show a => String -> a -> a
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dbg5 = tracePrettyAt 5
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dbg6 :: Show a => String -> a -> a
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dbg6 = tracePrettyAt 6
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dbg7 :: Show a => String -> a -> a
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dbg7 = tracePrettyAt 7
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dbg8 :: Show a => String -> a -> a
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dbg8 = tracePrettyAt 8
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dbg9 :: Show a => String -> a -> a
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dbg9 = tracePrettyAt 9
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-- | Convenience aliases for tracePrettyAtIO.
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-- Like dbg, but convenient to insert in an IO monad.
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-- XXX These have a bug; they should use traceIO, not trace,
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-- otherwise GHC can occasionally over-optimise
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-- (cf lpaste a few days ago where it killed/blocked a child thread).
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dbg0IO :: (MonadIO m, Show a) => String -> a -> m ()
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dbg0IO = tracePrettyAtIO 0
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dbg1IO :: (MonadIO m, Show a) => String -> a -> m ()
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dbg1IO = tracePrettyAtIO 1
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dbg2IO :: (MonadIO m, Show a) => String -> a -> m ()
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dbg2IO = tracePrettyAtIO 2
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dbg3IO :: (MonadIO m, Show a) => String -> a -> m ()
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dbg3IO = tracePrettyAtIO 3
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dbg4IO :: (MonadIO m, Show a) => String -> a -> m ()
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dbg4IO = tracePrettyAtIO 4
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dbg5IO :: (MonadIO m, Show a) => String -> a -> m ()
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dbg5IO = tracePrettyAtIO 5
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dbg6IO :: (MonadIO m, Show a) => String -> a -> m ()
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dbg6IO = tracePrettyAtIO 6
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dbg7IO :: (MonadIO m, Show a) => String -> a -> m ()
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dbg7IO = tracePrettyAtIO 7
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dbg8IO :: (MonadIO m, Show a) => String -> a -> m ()
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dbg8IO = tracePrettyAtIO 8
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dbg9IO :: (MonadIO m, Show a) => String -> a -> m ()
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dbg9IO = tracePrettyAtIO 9
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-- | Pretty-print a message and a showable value to the console if the debug level is at or above the specified level.
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-- At level 0, always prints. Otherwise, uses unsafePerformIO.
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tracePrettyAt :: Show a => Int -> String -> a -> a
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tracePrettyAt lvl = dbgppshow lvl
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-- tracePrettyAtM :: (Monad m, Show a) => Int -> String -> a -> m a
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-- tracePrettyAtM lvl lbl x = tracePrettyAt lvl lbl x `seq` return x
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-- XXX Could not deduce (a ~ ())
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-- from the context (Show a)
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--   bound by the type signature for
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--              dbgM :: Show a => String -> a -> IO ()
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--   at hledger/Hledger/Cli/Main.hs:200:13-42
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--   ‘a’ is a rigid type variable bound by
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--       the type signature for dbgM :: Show a => String -> a -> IO ()
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--       at hledger/Hledger/Cli/Main.hs:200:13
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-- Expected type: String -> a -> IO ()
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--   Actual type: String -> a -> IO a
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tracePrettyAtIO :: (MonadIO m, Show a) => Int -> String -> a -> m ()
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tracePrettyAtIO lvl lbl x = liftIO $ tracePrettyAt lvl lbl x `seq` return ()
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log0 :: Show a => String -> a -> a
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log0 = logPrettyAt 0
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-- | Log a message and a pretty-printed showable value to ./debug.log, 
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-- if the debug level is at or above the specified level.
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-- At level 0, always logs. Otherwise, uses unsafePerformIO.
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logPrettyAt :: Show a => Int -> String -> a -> a
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logPrettyAt lvl
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    | lvl > 0 && debugLevel < lvl = flip const
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    | otherwise = \s a -> 
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        let p = ppShow a
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            ls = lines p
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            nlorspace | length ls > 1 = "\n"
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                      | otherwise     = " " ++ take (10 - length s) (repeat ' ')
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            ls' | length ls > 1 = map (" "++) ls
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                | otherwise     = ls
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            output = s++":"++nlorspace++intercalate "\n" ls'
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        in unsafePerformIO $ appendFile "debug.log" output >> return a
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-- | print this string to the console before evaluating the expression,
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-- if the global debug level is at or above the specified level.  Uses unsafePerformIO.
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-- dbgtrace :: Int -> String -> a -> a
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-- dbgtrace level
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--     | debugLevel >= level = trace
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--     | otherwise           = flip const
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-- | Print a showable value to the console, with a message, if the
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-- debug level is at or above the specified level (uses
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-- unsafePerformIO).
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-- Values are displayed with show, all on one line, which is hard to read.
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-- dbgshow :: Show a => Int -> String -> a -> a
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-- dbgshow level
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--     | debugLevel >= level = ltrace
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--     | otherwise           = flip const
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-- | Print a showable value to the console, with a message, if the
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-- debug level is at or above the specified level (uses
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-- unsafePerformIO).
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-- Values are displayed with ppShow, each field/constructor on its own line.
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dbgppshow :: Show a => Int -> String -> a -> a
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dbgppshow level
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    | level > 0 && debugLevel < level = flip const
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    | otherwise = \s a -> let p = ppShow a
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                              ls = lines p
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                              nlorspace | length ls > 1 = "\n"
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                                        | otherwise     = " " ++ take (10 - length s) (repeat ' ')
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                              ls' | length ls > 1 = map (" "++) ls
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                                  | otherwise     = ls
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                          in trace (s++":"++nlorspace++intercalate "\n" ls') a
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-- -- | Print a showable value to the console, with a message, if the
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-- -- debug level is at or above the specified level (uses
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-- -- unsafePerformIO).
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-- -- Values are displayed with pprint. Field names are not shown, but the
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-- -- output is compact with smart line wrapping, long data elided,
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-- -- and slow calculations timed out.
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-- dbgpprint :: Data a => Int -> String -> a -> a
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-- dbgpprint level msg a
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--     | debugLevel >= level = unsafePerformIO $ do
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--                               pprint a >>= putStrLn . ((msg++": \n") ++) . show
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--                               return a
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--     | otherwise           = a
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-- | Like dbg, then exit the program. Uses unsafePerformIO.
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dbgExit :: Show a => String -> a -> a
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dbgExit msg = const (unsafePerformIO exitFailure) . dbg0 msg
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-- | Print a message and parsec debug info (parse position and next
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-- input) to the console when the debug level is at or above
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-- this level. Uses unsafePerformIO.
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-- pdbgAt :: GenParser m => Float -> String -> m ()
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pdbg :: Int -> String -> TextParser m ()
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pdbg level msg = when (level <= debugLevel) $ ptrace msg
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-- | Like dbg, but writes the output to "debug.log" in the current directory.
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-- Uses unsafePerformIO. Can fail due to log file contention if called too quickly
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-- ("*** Exception: debug.log: openFile: resource busy (file is locked)").
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dbglog :: Show a => String -> a -> a
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dbglog label a =
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  (unsafePerformIO $
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    appendFile "debug.log" $ label ++ ": " ++ ppShow a ++ "\n")
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  `seq` a
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