git-annex/Git/AutoCorrect.hs
Joey Hess e213ef310f git-annex (5.20140717) unstable; urgency=high
* Fix minor FD leak in journal code. Closes: #754608
  * direct: Fix handling of case where a work tree subdirectory cannot
    be written to due to permissions.
  * migrate: Avoid re-checksumming when migrating from hashE to hash backend.
  * uninit: Avoid failing final removal in some direct mode repositories
    due to file modes.
  * S3: Deal with AWS ACL configurations that do not allow creating or
    checking the location of a bucket, but only reading and writing content to
    it.
  * resolvemerge: New plumbing command that runs the automatic merge conflict
    resolver.
  * Deal with change in git 2.0 that made indirect mode merge conflict
    resolution leave behind old files.
  * sync: Fix git sync with local git remotes even when they don't have an
    annex.uuid set. (The assistant already did so.)
  * Set gcrypt-publish-participants when setting up a gcrypt repository,
    to avoid unncessary passphrase prompts.
    This is a security/usability tradeoff. To avoid exposing the gpg key
    ids who can decrypt the repository, users can unset
    gcrypt-publish-participants.
  * Install nautilus hooks even when ~/.local/share/nautilus/ does not yet
    exist, since it is not automatically created for Gnome 3 users.
  * Windows: Move .vbs files out of git\bin, to avoid that being in the
    PATH, which caused some weird breakage. (Thanks, divB)
  * Windows: Fix locking issue that prevented the webapp starting
    (since 5.20140707).

# imported from the archive
2014-07-17 11:27:25 -04:00

71 lines
2.1 KiB
Haskell

{- git autocorrection using Damerau-Levenshtein edit distance
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Git.AutoCorrect where
import Common
import Git.Types
import qualified Git.Config
import Text.EditDistance
import Control.Concurrent
{- These are the same cost values as used in git. -}
gitEditCosts :: EditCosts
gitEditCosts = EditCosts
{ deletionCosts = ConstantCost 4
, insertionCosts = ConstantCost 1
, substitutionCosts = ConstantCost 2
, transpositionCosts = ConstantCost 0
}
{- Git's source calls this "an empirically derived magic number" -}
similarityFloor :: Int
similarityFloor = 7
{- Finds inexact matches for the input among the choices.
- Returns an ordered list of good enough matches, or an empty list if
- nothing matches well. -}
fuzzymatches :: String -> (c -> String) -> [c] -> [c]
fuzzymatches input showchoice choices = fst $ unzip $
sortBy comparecost $ filter similarEnough $ zip choices costs
where
distance = restrictedDamerauLevenshteinDistance gitEditCosts input
costs = map (distance . showchoice) choices
comparecost a b = compare (snd a) (snd b)
similarEnough (_, cst) = cst < similarityFloor
{- Takes action based on git's autocorrect configuration, in preparation for
- an autocorrected command being run. -}
prepare :: String -> (c -> String) -> [c] -> Repo -> IO ()
prepare input showmatch matches r =
case readish $ Git.Config.get "help.autocorrect" "0" r of
Just n
| n == 0 -> list
| n < 0 -> warn
| otherwise -> sleep n
Nothing -> list
where
list = error $ unlines $
[ "Unknown command '" ++ input ++ "'"
, ""
, "Did you mean one of these?"
] ++ map (\m -> "\t" ++ showmatch m) matches
warn =
hPutStr stderr $ unlines
[ "WARNING: You called a command named '" ++
input ++ "', which does not exist."
, "Continuing under the assumption that you meant '" ++
showmatch (Prelude.head matches) ++ "'"
]
sleep n = do
warn
hPutStrLn stderr $ unwords
[ "in"
, show (fromIntegral n / 10 :: Float)
, "seconds automatically..."]
threadDelay (n * 100000) -- deciseconds to microseconds