System.Console.Haskeline.History

This module provides a low-level API to the line history stored in the InputT monad transformer.

For most application, it should suffice to instead use the following Settings flags:

• autoAddHistory: add nonblank lines to the command history (True by default).
• historyFile: read/write the history to a file before and after the line input session.

If you do want custom history behavior, you may need to disable the above default setting(s).

Documentation

data History

Instances

Show History

Defined in System.Console.Haskeline.History

Methods

showsPrec :: Int -> History -> ShowS

show :: History -> String

showList :: [History] -> ShowS

emptyHistory :: History

addHistory :: String -> History -> History

addHistoryUnlessConsecutiveDupe :: String -> History -> History

Add a line to the history unless it matches the previously recorded line.

addHistoryRemovingAllDupes :: String -> History -> History

Add a line to the history, and remove all previous entries which are the same as it.

historyLines :: History -> [String]

The input lines stored in the history (newest first)

readHistory :: FilePath -> IO History

Reads the line input history from the given file. Returns emptyHistory if the file does not exist or could not be read.

writeHistory :: FilePath -> History -> IO ()

Writes the line history to the given file. If there is an error when writing the file, it will be ignored.

stifleHistory :: Maybe Int -> History -> History

Limit the number of lines stored in the history.

stifleAmount :: History -> Maybe Int

The maximum number of lines stored in the history. If Nothing, the history storage is unlimited.