hledger/hledger-lib/Hledger/Utils.hs
2019-01-26 15:52:58 -08:00

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{-|
Standard imports and utilities which are useful everywhere, or needed low
in the module hierarchy. This is the bottom of hledger's module graph.
-}
{-# LANGUAGE OverloadedStrings, LambdaCase #-}
module Hledger.Utils (---- provide these frequently used modules - or not, for clearer api:
-- module Control.Monad,
-- module Data.List,
-- module Data.Maybe,
-- module Data.Time.Calendar,
-- module Data.Time.Clock,
-- module Data.Time.LocalTime,
-- module Data.Tree,
-- module Text.RegexPR,
-- module Text.Printf,
---- all of this one:
module Hledger.Utils,
module Hledger.Utils.Debug,
module Hledger.Utils.Parse,
module Hledger.Utils.Regex,
module Hledger.Utils.String,
module Hledger.Utils.Text,
module Hledger.Utils.Test,
module Hledger.Utils.Color,
module Hledger.Utils.Tree,
-- Debug.Trace.trace,
-- module Data.PPrint,
-- module Hledger.Utils.UTF8IOCompat
SystemString,fromSystemString,toSystemString,error',userError',usageError,
-- the rest need to be done in each module I think
)
where
import Control.Monad (liftM, when)
-- import Data.Char
import Data.Default
import Data.FileEmbed (makeRelativeToProject, embedFile)
import Data.List
-- import Data.Maybe
-- import Data.PPrint
import Data.String.Here (hereFile)
import Data.Text (Text)
import qualified Data.Text.IO as T
import Data.Time.Clock
import Data.Time.LocalTime
-- import Data.Text (Text)
-- import qualified Data.Text as T
import Language.Haskell.TH.Quote (QuasiQuoter(..))
import Language.Haskell.TH.Syntax (Q, Exp)
import System.Directory (getHomeDirectory)
import System.FilePath((</>), isRelative)
import System.IO
-- import Text.Printf
-- import qualified Data.Map as Map
import Hledger.Utils.Debug
import Hledger.Utils.Parse
import Hledger.Utils.Regex
import Hledger.Utils.String
import Hledger.Utils.Text
import Hledger.Utils.Test
import Hledger.Utils.Color
import Hledger.Utils.Tree
-- import Prelude hiding (readFile,writeFile,appendFile,getContents,putStr,putStrLn)
-- import Hledger.Utils.UTF8IOCompat (readFile,writeFile,appendFile,getContents,putStr,putStrLn)
import Hledger.Utils.UTF8IOCompat (SystemString,fromSystemString,toSystemString,error',userError',usageError)
-- tuples
first3 (x,_,_) = x
second3 (_,x,_) = x
third3 (_,_,x) = x
first4 (x,_,_,_) = x
second4 (_,x,_,_) = x
third4 (_,_,x,_) = x
fourth4 (_,_,_,x) = x
first5 (x,_,_,_,_) = x
second5 (_,x,_,_,_) = x
third5 (_,_,x,_,_) = x
fourth5 (_,_,_,x,_) = x
fifth5 (_,_,_,_,x) = x
first6 (x,_,_,_,_,_) = x
second6 (_,x,_,_,_,_) = x
third6 (_,_,x,_,_,_) = x
fourth6 (_,_,_,x,_,_) = x
fifth6 (_,_,_,_,x,_) = x
sixth6 (_,_,_,_,_,x) = x
-- lists
splitAtElement :: Eq a => a -> [a] -> [[a]]
splitAtElement x l =
case l of
[] -> []
e:es | e==x -> split es
es -> split es
where
split es = let (first,rest) = break (x==) es
in first : splitAtElement x rest
-- text
-- time
getCurrentLocalTime :: IO LocalTime
getCurrentLocalTime = do
t <- getCurrentTime
tz <- getCurrentTimeZone
return $ utcToLocalTime tz t
getCurrentZonedTime :: IO ZonedTime
getCurrentZonedTime = do
t <- getCurrentTime
tz <- getCurrentTimeZone
return $ utcToZonedTime tz t
-- misc
instance Default Bool where def = False
isLeft :: Either a b -> Bool
isLeft (Left _) = True
isLeft _ = False
isRight :: Either a b -> Bool
isRight = not . isLeft
-- | Apply a function the specified number of times,
-- which should be > 0 (otherwise does nothing).
-- Possibly uses O(n) stack ?
applyN :: Int -> (a -> a) -> a -> a
applyN n f | n < 1 = id
| otherwise = (!! n) . iterate f
-- from protolude, compare
-- applyN :: Int -> (a -> a) -> a -> a
-- applyN n f = X.foldr (.) identity (X.replicate n f)
-- | Convert a possibly relative, possibly tilde-containing file path to an absolute one,
-- given the current directory. ~username is not supported. Leave "-" unchanged.
-- Can raise an error.
expandPath :: FilePath -> FilePath -> IO FilePath -- general type sig for use in reader parsers
expandPath _ "-" = return "-"
expandPath curdir p = (if isRelative p then (curdir </>) else id) `liftM` expandHomePath p
-- | Expand user home path indicated by tilde prefix
expandHomePath :: FilePath -> IO FilePath
expandHomePath = \case
('~':'/':p) -> (</> p) <$> getHomeDirectory
('~':'\\':p) -> (</> p) <$> getHomeDirectory
('~':_) -> ioError $ userError "~USERNAME in paths is not supported"
p -> return p
firstJust ms = case dropWhile (==Nothing) ms of
[] -> Nothing
(md:_) -> md
-- | Read text from a file,
-- handling any of the usual line ending conventions,
-- using the system locale's text encoding,
-- ignoring any utf8 BOM prefix (as seen in paypal's 2018 CSV, eg) if that encoding is utf8.
readFilePortably :: FilePath -> IO Text
readFilePortably f = openFile f ReadMode >>= readHandlePortably
-- | Like readFilePortably, but read from standard input if the path is "-".
readFileOrStdinPortably :: String -> IO Text
readFileOrStdinPortably f = openFileOrStdin f ReadMode >>= readHandlePortably
where
openFileOrStdin :: String -> IOMode -> IO Handle
openFileOrStdin "-" _ = return stdin
openFileOrStdin f m = openFile f m
readHandlePortably :: Handle -> IO Text
readHandlePortably h = do
hSetNewlineMode h universalNewlineMode
menc <- hGetEncoding h
when (fmap show menc == Just "UTF-8") $ -- XXX no Eq instance, rely on Show
hSetEncoding h utf8_bom
T.hGetContents h
-- | Total version of maximum, for integral types, giving 0 for an empty list.
maximum' :: Integral a => [a] -> a
maximum' [] = 0
maximum' xs = maximumStrict xs
-- | Strict version of sum that doesnt leak space
{-# INLINABLE sumStrict #-}
sumStrict :: Num a => [a] -> a
sumStrict = foldl' (+) 0
-- | Strict version of maximum that doesnt leak space
{-# INLINABLE maximumStrict #-}
maximumStrict :: Ord a => [a] -> a
maximumStrict = foldl1' max
-- | Strict version of minimum that doesnt leak space
{-# INLINABLE minimumStrict #-}
minimumStrict :: Ord a => [a] -> a
minimumStrict = foldl1' min
-- | This is a version of sequence based on difference lists. It is
-- slightly faster but we mostly use it because it uses the heap
-- instead of the stack. This has the advantage that Neil Mitchells
-- trick of limiting the stack size to discover space leaks doesnt
-- show this as a false positive.
{-# INLINABLE sequence' #-}
sequence' :: Monad f => [f a] -> f [a]
sequence' ms = do
h <- go id ms
return (h [])
where
go h [] = return h
go h (m:ms) = do
x <- m
go (h . (x :)) ms
{-# INLINABLE mapM' #-}
mapM' :: Monad f => (a -> f b) -> [a] -> f [b]
mapM' f = sequence' . map f
-- | Like embedFile, but takes a path relative to the package directory.
-- Similar to hereFileRelative ?
embedFileRelative :: FilePath -> Q Exp
embedFileRelative f = makeRelativeToProject f >>= embedFile
-- | Like hereFile, but takes a path relative to the package directory.
-- Similar to embedFileRelative ?
hereFileRelative :: FilePath -> Q Exp
hereFileRelative f = makeRelativeToProject f >>= hereFileExp
where
QuasiQuoter{quoteExp=hereFileExp} = hereFile
tests_Utils = tests "Utils" [
tests_Text
]