Module CPM.ErrorLogger

Contains combinators for chaining IO actions that can fail and log messages.

Summary of exported operations:

logLevelOf
                  ::  LogEntry -> LogLevel

getLogLevel
                  ::  IO LogLevel

Gets the global log level.

setLogLevel
                  ::  LogLevel -> IO ()

Sets the global log level.

setWithShowTime
                  ::  Bool -> IO ()

Sets the "show time" information.

(|>=)
                  ::  IO ([LogEntry],Either LogEntry a) -> (a -> IO ([LogEntry],Either LogEntry b)) -> IO ([LogEntry],Either LogEntry b)

Chains two actions passing the result from the first to the second.

(|>)
                  ::  IO ([LogEntry],Either LogEntry a) -> IO ([LogEntry],Either LogEntry b) -> IO ([LogEntry],Either LogEntry b)

Chains two actions ignoring the result of the first.

(|->)
                  ::  IO ([LogEntry],Either LogEntry a) -> IO ([LogEntry],Either LogEntry b) -> IO ([LogEntry],Either LogEntry a)

Chains two actions ignoring the result of the second.

(|>>)
                  ::  IO a -> IO ([LogEntry],Either LogEntry b) -> IO ([LogEntry],Either LogEntry b)

Chains a standard IO action (where the result is ignored) with an error logger action.

mapEL
                  ::  (a -> IO ([LogEntry],Either LogEntry b)) -> [a] -> IO ([LogEntry],Either LogEntry [b])

Maps an action over a list of values.

foldEL
                  ::  (a -> b -> IO ([LogEntry],Either LogEntry a)) -> a -> [b] -> IO ([LogEntry],Either LogEntry a)

Folds a list of values using an action.

showLogEntry
                  ::  LogEntry -> IO ()

Renders a log entry to stderr.

levelGte
                  ::  LogLevel -> LogLevel -> Bool

Compares two log levels.

succeedIO
                  ::  a -> IO ([LogEntry],Either LogEntry a)

Create an IO action that always succeeds.

failIO
                  ::  String -> IO ([LogEntry],Either LogEntry a)

Create an IO action that always fails.

log
                  ::  LogLevel -> String -> IO ([LogEntry],Either LogEntry ())

Create an IO action that logs a message.

infoMessage
                  ::  String -> IO ()

Prints an info message in the standard IO monad.

debugMessage
                  ::  String -> IO ()

Prints a debug message in the standard IO monad.

errorMessage
                  ::  String -> IO ()

Prints an error message in the standard IO monad.

fromErrorLogger
                  ::  IO ([LogEntry],Either LogEntry a) -> IO a

Transforms an error logger actions into a standard IO action.

showExecCmd
                  ::  String -> IO Int

Executes a system command and show the command as debug message.

execQuietCmd
                  ::  (String -> String) -> IO Int

Executes a parameterized system command.

Exported datatypes:

ErrorLogger

An error logger.

Type synonym: ErrorLogger a = ([LogEntry],Either LogEntry a)

LogEntry

A log entry.

Constructors:

LogLevel

A log level.

Constructors:

Quiet :: LogLevel
Info :: LogLevel
Debug :: LogLevel
Error :: LogLevel
Critical :: LogLevel

Exported operations:

logLevelOf :: LogEntry -> LogLevel

Further infos:

solution complete, i.e., able to compute all solutions

getLogLevel :: IO LogLevel

Gets the global log level. Messages below this level will not be printed.

setLogLevel :: LogLevel -> IO ()

Sets the global log level. Messages below this level will not be printed.

setWithShowTime :: Bool -> IO ()

Sets the "show time" information. If true, then timing information will be shown with every log information.

(|>=) :: IO ([LogEntry],Either LogEntry a) -> (a -> IO ([LogEntry],Either LogEntry b)) -> IO ([LogEntry],Either LogEntry b)

Chains two actions passing the result from the first to the second.

Further infos:

defined as left-associative infix operator with precedence 0

(|>) :: IO ([LogEntry],Either LogEntry a) -> IO ([LogEntry],Either LogEntry b) -> IO ([LogEntry],Either LogEntry b)

Chains two actions ignoring the result of the first.

Further infos:

defined as left-associative infix operator with precedence 0

(|->) :: IO ([LogEntry],Either LogEntry a) -> IO ([LogEntry],Either LogEntry b) -> IO ([LogEntry],Either LogEntry a)

Chains two actions ignoring the result of the second.

Further infos:

defined as left-associative infix operator with precedence 0

(|>>) :: IO a -> IO ([LogEntry],Either LogEntry b) -> IO ([LogEntry],Either LogEntry b)

Chains a standard IO action (where the result is ignored) with an error logger action.

Further infos:

defined as left-associative infix operator with precedence 0

mapEL :: (a -> IO ([LogEntry],Either LogEntry b)) -> [a] -> IO ([LogEntry],Either LogEntry [b])

Maps an action over a list of values. Fails if one of the actions fails.

foldEL :: (a -> b -> IO ([LogEntry],Either LogEntry a)) -> a -> [b] -> IO ([LogEntry],Either LogEntry a)

Folds a list of values using an action. Fails if one of the actions fails.

showLogEntry :: LogEntry -> IO ()

Renders a log entry to stderr.

levelGte :: LogLevel -> LogLevel -> Bool

Compares two log levels.

Further infos:

solution complete, i.e., able to compute all solutions

succeedIO :: a -> IO ([LogEntry],Either LogEntry a)

Create an IO action that always succeeds.

failIO :: String -> IO ([LogEntry],Either LogEntry a)

Create an IO action that always fails.

log :: LogLevel -> String -> IO ([LogEntry],Either LogEntry ())

Create an IO action that logs a message.

infoMessage :: String -> IO ()

Prints an info message in the standard IO monad.

debugMessage :: String -> IO ()

Prints a debug message in the standard IO monad.

errorMessage :: String -> IO ()

Prints an error message in the standard IO monad.

fromErrorLogger :: IO ([LogEntry],Either LogEntry a) -> IO a

Transforms an error logger actions into a standard IO action. It shows all messages and, if the result is not available, exits with a non-zero code.

showExecCmd :: String -> IO Int

Executes a system command and show the command as debug message.

execQuietCmd :: (String -> String) -> IO Int

Executes a parameterized system command. The parameter is set to -q unless the LogLevel is Debug.