RIO.Logger

Documentation

data LogLevel

Constructors

LevelDebug

LevelInfo

LevelWarn

LevelError

LevelOther !Text

Instances

Eq LogLevel

Methods

(==) :: LogLevel -> LogLevel -> Bool

(/=) :: LogLevel -> LogLevel -> Bool

Ord LogLevel

Methods

compare :: LogLevel -> LogLevel -> Ordering

(<) :: LogLevel -> LogLevel -> Bool

(<=) :: LogLevel -> LogLevel -> Bool

(>) :: LogLevel -> LogLevel -> Bool

(>=) :: LogLevel -> LogLevel -> Bool

max :: LogLevel -> LogLevel -> LogLevel

min :: LogLevel -> LogLevel -> LogLevel

Read LogLevel

Methods

readsPrec :: Int -> ReadS LogLevel

readList :: ReadS [LogLevel]

readPrec :: ReadPrec LogLevel

readListPrec :: ReadPrec [LogLevel]

Show LogLevel

Methods

showsPrec :: Int -> LogLevel -> ShowS

show :: LogLevel -> String

showList :: [LogLevel] -> ShowS

HasLogFunc LogFunc

Methods

logFuncL :: SimpleGetter LogFunc LogFunc

type LogSource = Text

type LogStr = DisplayBuilder

type LogFunc = CallStack -> LogSource -> LogLevel -> LogStr -> IO ()

data CallStack :: *

CallStacks are a lightweight method of obtaining a partial call-stack at any point in the program.

A function can request its call-site with the HasCallStack constraint. For example, we can define

errorWithCallStack :: HasCallStack => String -> a

as a variant of error that will get its call-site. We can access the call-stack inside errorWithCallStack with callStack.

errorWithCallStack :: HasCallStack => String -> a
errorWithCallStack msg = error (msg ++ "n" ++ prettyCallStack callStack)

Thus, if we call errorWithCallStack we will get a formatted call-stack alongside our error message.

>>> errorWithCallStack "die"
*** Exception: die
CallStack (from HasCallStack):
  errorWithCallStack, called at <interactive>:2:1 in interactive:Ghci1

GHC solves HasCallStack constraints in three steps:

1. If there is a CallStack in scope -- i.e. the enclosing function has a HasCallStack constraint -- GHC will append the new call-site to the existing CallStack.
2. If there is no CallStack in scope -- e.g. in the GHCi session above -- and the enclosing definition does not have an explicit type signature, GHC will infer a HasCallStack constraint for the enclosing definition (subject to the monomorphism restriction).
3. If there is no CallStack in scope and the enclosing definition has an explicit type signature, GHC will solve the HasCallStack constraint for the singleton CallStack containing just the current call-site.

CallStacks do not interact with the RTS and do not require compilation with -prof. On the other hand, as they are built up explicitly via the HasCallStack constraints, they will generally not contain as much information as the simulated call-stacks maintained by the RTS.

A CallStack is a [(String, SrcLoc)]. The String is the name of function that was called, the SrcLoc is the call-site. The list is ordered with the most recently called function at the head.

NOTE: The intrepid user may notice that HasCallStack is just an alias for an implicit parameter ?callStack :: CallStack. This is an implementation detail and should not be considered part of the CallStack API, we may decide to change the implementation in the future.

Since: 4.8.1.0

Instances

IsList CallStack

Be aware that 'fromList . toList = id' only for unfrozen CallStacks, since toList removes frozenness information.

Since: 4.9.0.0

Associated Types

type Item CallStack :: *

Methods

fromList :: [Item CallStack] -> CallStack

fromListN :: Int -> [Item CallStack] -> CallStack

toList :: CallStack -> [Item CallStack]

Show CallStack

Since: 4.9.0.0

Methods

showsPrec :: Int -> CallStack -> ShowS

show :: CallStack -> String

showList :: [CallStack] -> ShowS

NFData CallStack

Since: 1.4.2.0

Methods

rnf :: CallStack -> ()

HasLogFunc LogFunc

Methods

logFuncL :: SimpleGetter LogFunc LogFunc

type Item CallStack

type Item CallStack = (String, SrcLoc)

class HasLogFunc env where

Minimal complete definition

logFuncL

Methods

logFuncL :: SimpleGetter env LogFunc

Instances

HasLogFunc NoLogging

Methods

logFuncL :: SimpleGetter NoLogging LogFunc

HasLogFunc LogFunc

Methods

logFuncL :: SimpleGetter LogFunc LogFunc

logGeneric :: (MonadIO m, MonadReader env m, HasLogFunc env, HasCallStack) => LogSource -> LogLevel -> LogStr -> m ()

logDebug :: (MonadIO m, MonadReader env m, HasLogFunc env, HasCallStack) => LogStr -> m ()

logInfo :: (MonadIO m, MonadReader env m, HasLogFunc env, HasCallStack) => LogStr -> m ()

logWarn :: (MonadIO m, MonadReader env m, HasLogFunc env, HasCallStack) => LogStr -> m ()

logError :: (MonadIO m, MonadReader env m, HasLogFunc env, HasCallStack) => LogStr -> m ()

logDebugS :: (MonadIO m, MonadReader env m, HasLogFunc env, HasCallStack) => LogSource -> LogStr -> m ()

logInfoS :: (MonadIO m, MonadReader env m, HasLogFunc env, HasCallStack) => LogSource -> LogStr -> m ()

logWarnS :: (MonadIO m, MonadReader env m, HasLogFunc env, HasCallStack) => LogSource -> LogStr -> m ()

logErrorS :: (MonadIO m, MonadReader env m, HasLogFunc env, HasCallStack) => LogSource -> LogStr -> m ()

logOther

Arguments

:: (MonadIO m, MonadReader env m, HasLogFunc env, HasCallStack)

=> Text

level

-> LogStr

-> m ()

logSticky :: (MonadIO m, HasCallStack, MonadReader env m, HasLogFunc env) => LogStr -> m ()

Write a "sticky" line to the terminal. Any subsequent lines will overwrite this one, and that same line will be repeated below again. In other words, the line sticks at the bottom of the output forever. Running this function again will replace the sticky line with a new sticky line. When you want to get rid of the sticky line, run logStickyDone.

logStickyDone :: (MonadIO m, HasCallStack, MonadReader env m, HasLogFunc env) => LogStr -> m ()

This will print out the given message with a newline and disable any further stickiness of the line until a new call to logSticky happens.

It might be better at some point to have a runSticky function that encompasses the logSticky->logStickyDone pairing.

runNoLogging :: MonadIO m => ReaderT NoLogging m a -> m a

data NoLogging

Constructors

NoLogging

Instances

HasLogFunc NoLogging

Methods

logFuncL :: SimpleGetter NoLogging LogFunc

withStickyLogger :: MonadUnliftIO m => LogOptions -> (LogFunc -> m a) -> m a

data LogOptions

Constructors

LogOptions

Fields

• logMinLevel :: !LogLevel
• logVerboseFormat :: !Bool
• logTerminal :: !Bool
• logUseTime :: !Bool
• logUseColor :: !Bool
• logSend :: !(Builder -> IO ())

displayCallStack :: CallStack -> DisplayBuilder

mkLogOptions

Arguments

:: MonadIO m

=> Handle

-> Bool

verbose?

-> m LogOptions