Changelog for HLint (* = breaking change)

#1290, move reverse out of filter

3.3.4, released 2021-08-30

#1288, fix generation of Linux binaries

3.3.3, released 2021-08-29

#1286, compatibility with extra-1.7.10

#114, if OverloadedLists are enabled, don't suggest list literals

3.3.2, released 2021-08-28

#1244, add `only` restriction to modules

#1278, make --ignore-glob patterns also ignore directories

#1268, move nub/sort/reverse over catMaybes/lefts/rights

#1276, fix some incorrect unused LANGUAGE warnings

#1271, suggest foldr (<>) mempty ==> fold (not mconcat)

#1274, make the (& f) ==> f hint apply more

#1264, suggest eta reduction under a where

#1266, suggest () <$ x ==> void x

#1223, add some traverse laws

#1254, suggest null [x] ==> False

#1253, suggest reverse . init ==> tail . reverse

#1253, suggest null . concat ==> all null

#1255, suggest filter instead of list comprehension in teaching

3.3.1, released 2021-04-26

#1221, allow restrictions to use wildcards

#1225, treat A{} as not-atomic for bracket hints

#1233, -XHaskell98 and -XHaskell2010 now disable extensions too

#1226, don't warn on top-level splices with brackets

#1230, disable LexicalNegation by default

#1219, suggest uncurry f (a, b) ==> f a b

#1227, remove some excess brackets generated by refactoring

3.3, released 2021-03-14

#1212, don't suggest redundant brackets on $(x)

#1215, suggest varE 'foo ==> [|foo|]

#1215, allow matching on Template Haskell variables

#1216, require apply-refact 0.9.1.0

* #1209, switch to the GHC 9.0.1 parse tree

Drop GHC 8.6 support

#1206, require apply-refact 0.9.0.0 or higher

#1205, generalize hints which were with '&' form

3.2.7, released 2021-01-16

#1202, add missing parentheses for Avoid Lambda

#1201, allow matching through the & operator (similar to $)

#1196, fix removed parens with operator sections in some cases

3.2.6, released 2020-12-30

Fixes to the release generation script

3.2.5, released 2020-12-30

Fixes to the release generation script

3.2.4, released 2020-12-30

#1193, add warnings for redundant flip

#1183, allow matches where users specify unnecessary brackets

#1177, remove suggestions for fromMaybe False/fromMaybe True

#1176, suggest use of unzip

#1159, spot redundant brackets due to fixities, default ignored

#1172, suggest reusing fromLeft/fromRight

3.2.3, released 2020-11-23

#1160, never consult the .hscolour file for color preferences

#1171, do not refactor redundant lambda with case

#1169, default to -A32 (doubles speed for 4 CPU)

#1169, make -j actually use parallelism

#1167, enable refactoring for "Use lambda"

3.2.2, released 2020-11-15

#1166, detect more unboxed data to avoid suggesting newtype

#1153, fix incorrect redundant bracket with @($foo)

#1163, do not suggest "Use lambda" when there are guards

#1160, add showIdeaANSI to show Idea values with escape codes

3.2.1, released 2020-10-15

#1150, remove the Duplicate hint (was slow)

#1149, allow within to use module wildcards, e.g. **.Foo

#1141, make redundant return highlight just the return

#1142, suggest newtype instead of data for data family instances

#1138, show allowed fields in YAML error message

#1131, fix potential variable capture in zipWith/repeat hint

#1129, add hints to use const and \_ x -> x where appropriate

3.2, released 2020-09-14

#75, make Windows 10 use color terminals

Make sure the extension removed matches what you called it

* #1124, make test into a flag rather than a mode, use --test

#1073, add LHS/RHS hints to the summary

* Remove test --proof, --quickcheck and --typecheck, --tempdir

* #1123, delete grep mode

#1122, show the --refactor command line with --loud

#1120, enable refactoring for use section

#1114, enable refactoring for redundant as-pattern

#1116, enable refactoring for redundant section

#1115, more TVar/TMVar hints

#1113, suggest x >>= pure . f becomes x <&> f

#1111, add hint for \x y -> (x,y) to (,), and for (,,)

#1108, enable refactoring for redundant variable capture

#1105, enable refactoring for more redundant return hints

#1103, enable refactoring for Redundant void

#1083, add hints for mempty as a function

#1097, enable refactoring for more avoid lambda hints

#1094, error on `-XFoo` if `Foo` is not a known extension

#1090, improve --verbose to print more information

#1085, support eta-reduce refactoring

#780, ignore dist and dist-newstyle directories

#1076, fix -XNoCpp and CPP around LANGUAGE extensions

#1077, warn on unused StandaloneKindSignatures

#1070, warn on unused ImportQualifiedPost

#1067, require apply-refact 0.8.1.0 (fixes lots of bugs)

#1064, don't remove OverloadedLists if there is a []

3.1.6, released 2020-06-24

#1062, make sure matching inserts brackets if required

#1058, weaken the self-definition check to match more things

#1060, suggest [] ++ x and [] ++ x to x

3.1.5, released 2020-06-19

#1049, suggest or/and from True `elem` xs and False `notElem` xs

#1055, avoid incorrect hints with nested (.)'s

#1054, make isLitString work again

#1038, make -XNoTemplateHaskell imply -XNoTemplateHaskellQuotes

#970, require an arg to suggest fromMaybe True ==> (Just True ==)

#1047, suggest pushing take outside zip

#1041, fix language/pragma ordering in refactor

#1040, fix refactoring for "Avoid lambda"

#1042, fix redundant lambda refactoring

#1039, don't suggest move map inside list comp repeatedly

#1035, fix refactoring for "Use fewer imports" in some cases

#1036, disable refactoring for Use camelCase

#766, match quasi quotes properly in rules

Ignore [Char] to String hints by default

#1034, remove suggestions to use heirarchical module names

#1032, fix refactoring for "Use :"

#1028, add hints around sequenceA/traverse

#1027, pass enabled and disabled extensions to apply-refact

#1024, make the redundant bracket hints cover just the bracket

#1024, make redundant $ display more context on the command line

Suggest removing OverloadedLabels if there are no labels

#367, suggest removing OverloadedLists if there are no lists

#1023, speed up checking on large files (up to 12%)

3.1.4, released 2020-05-31

#1018, stop --cross being quadratic

#1019, more rules suggesting even/odd

3.1.3, released 2020-05-25

#1016, check scopes of restricted functions

3.1.2, released 2020-05-24

#1014, don't error on empty do blocks

#1008, make redundant do ignored by default

#1012, add CodeWorld hints around pictures

#1003, enable refactoring for (v1 . v2) <$> v3

#1002, warn on unused NumericUnderscores

3.1.1, released 2020-05-13

#993, deal with infix declarations in the module they occur

#993, make createModuleEx use the default HLint fixities

#995, add unpackSrcSpan to the API

3.1, released 2020-05-07

#979, suggest removing flip only for simple final variables

#978, do is not redundant with non-decreasing indentation

#969, wrong redundant bracket suggestion with BlockArguments

#970, detect redundant sections, (a +) b ==> a + b

* #974, split ParseFlags.extensions into enabled/disabled

#971, add support for -XNoFoo command line flags

#976, run refactor even if no hints

#971, add support for NoFoo language pragmas

3.0.4, released 2020-05-03

#968, fail on all parse errors

#967, enable TypeApplications by default

3.0.3, released 2020-05-03

#965, fix incorrect avoid lambda suggestion

3.0.2, released 2020-05-03

#963, don't generate use-section hints for tuples

#745, fix up free variables for A{x}, fixes list comp hints

3.0.1, released 2020-05-02

#961, don't crash on non-extension LANGUAGE pragmas, e.g. Safe

3.0, released 2020-05-02

Be more permissive with names'with'quotes'in

#953, fix incorrect suggestions with free variables and \case

#955, make --find generate fixity: not infix:

#952, improve refactorings with qualified imports

#945, suggest Map.fromList [] ==> Map.empty

#949, warn about redundant fmaps with binds

#950, reduce the span of "Redundant $" to only cover the "$"

#944, reduce the span of "Use let" to only cover the "let" line

#669, don't suggest replacing reverse . sort (it's quite fast)

#939, reduce the span of "Redundant where" to only cover the "where"

Remove support for GHC 8.4

Remove support for _eval,

#926, fix refactoring when the hint contains _noParen_

#933, improve the output for Redundant do hints

* Merge ParseMode into ParseFlags

* Rename Language.Haskell.HLint3,HLint4 to Language.Haskell.HLint

* Delete the old Language.Haskell.HLint

#881, add a monomorphic group of hints

#837, don't suggest redundant do if its being used for brackets

#923, don't suggest eta reducing infix definitions

#931, disable StaticPointers extension by default

#924, remove dependency on haskell-src-exts

#922, reduce the span of "Redundant do" to only cover the "do"

#919, more specific names for foldMap fusion rules

#918, warn on unused TypeOperators

#916, warn on unused InstanceSigs

Improve parse error context messages

* Most parse errors are fixed

#881, disable hints about maybe that are sometimes wrong

#909, be more careful about redundant bracket warnings

#905, match hints even if there is composition to the left

#904, suggest map/fromMaybe[] becomes maybe [] map

* Remove the hse command line argument, to parse a file with HSE

#901, warn on unused MultiWayIf

Don't raise a parse error if haskell-src-exts can't parse code

#899, warn on unused PatternSynonyms

#898, don't suggest removing NamedFieldPuns with record updates

* Make any --hint flag disable implicit .hlint.yaml search

* Delete the --with flag

* Haskell hint definitions are no longer supported (use YAML)

* Report hints with src-span information, e.g. file:1:1-10

* Delete resolveHints (it was the identity)

* Change to GHC types in the API

Add --with-group=future to add return ==> pure hint

#888, suggest foldr from (.) to ($) in some cases

#884, add more >=> operator hints

#875, fix the extension implication information

Add --with-group=extra to give extra library hints

#873, add more Applicative hints

#872, fix refactoring in hints to use lists

#871, warn when fmapping the result of gets or asks

#869, improve hints for maybe/fromMaybe on Bool

2.2.11, released 2020-02-09

#868, fix some brackets in refactoring suggestions

#865, suggest biList if generalise-for-conciseness is turned on

#859, suggest regular if instead of a simple multi-way if

#860, improve the sortBy/sortOn hints

#862, only suggest TupleSections for 2-tuples once

#854, add more generalise-for-conciseness hints for Either/Maybe

#852, change maybe to fromMaybe, when the function is duplicated

#851, add a rule for maybe Nothing Just

2.2.10, released 2020-02-02

#846, add splitAt warnings

#774, don't warn about 'Redundant compare' in == and /=

2.2.9, released 2020-01-27

Add any/map and all/map fusion hints

#837, don't warn about redundant do for BlockArguments

#842, fix parsing of <% operators in hlint.yaml files

#839, match hints inside instances

#833, UnboxedTuples can be necessary from newtype deriving

#817, add the ability to blacklist identifiers from a module

#834, move not out of any and all

2.2.8, released 2020-01-22

#802, suggest lambda instead of lambda-case for single alts

#811, add some foldMap/map hints

#822, generalise the map/zipWith hint

#824, embed HLint data files using TemplateHaskell

#826, remove curry/uncurry on lambdas

#820, make some hints work in more situations

Reenable PackageImport unused extension detectection

#821, warn on unless/not

#821, avoid curry/uncurry and vice versa

#819, fix a lot of bifunctor hints

#812, add some rules for generalised and/or/any/all

2.2.7, released 2020-01-11

#818, fix incorrect unused LANGUAGE BangPatterns hint

2.2.6, released 2020-01-09

#813, remove any/all with const predicates

Allow haskell-src-exts-1.23

#814, suggest find instead of listToMaybe/filter

Allow ghc-lib-parser-8.8.*

2.2.5, released 2019-12-06

#803, allow newer ghc-lib-8.8.1

#792, note that reverse/sort changes sort stability

#793, don't incorrectly suggest foldr

2.2.4, released 2019-11-02

Allow haskell-src-exts-1.22

#788, give less redundant context on unused variable capture

#334, add --ignore=glob flag

2.2.3, released 2019-09-29

#766, turn on more extensions when parsing config files

#255, don't match variables with type application

Switch to ghc-parser-8.8.1

Slightly restrict the replace case with fromMaybe hint

#701, add hints for replacing case with maybe

#724, suggest Data.Bifunctor in some places

#725, allow custom message for restricted items

2.2.2, released 2019-07-23

#716, upgrade to ghc-lib-parser 8.8.0.20190723

2.2.1, released 2019-07-22

#713, make sure -XNoPatternSynonyms works (fix regression)

#700, add some Monoid and Alternative hints

Add createModuleEx to the API

#698, don't suggest a replacement for DerivingStrategies

2.2, released 2019-06-26

* Remove functions and make some things abstract in HLint3 API

2.1.26, released 2019-06-26

Make sure unknown extensions don't cause errors

2.1.25, released 2019-06-26

#681, fix for extensions on the command line not being used

#686, suggest head (drop n x) ==> x !! max 0 n

#683, add Use DerivingStrategies hint, ignored by default

#685, skip running refactoring tool if there are no hints

#675, warn about redundant fmaps on Eithers and Maybes

Add back two $ hints removed in error

2.1.24, released 2019-06-10

Add Language.Haskell.HLint4

#658, ignore the previously undocumented {- LINT -} comments

#658, force parsing of all pragmas and comments eagerly

#665, make different fromMaybe hints have different names

#664, better name for the Use uncurry hint

#659, make hints with brackets at the root work

2.1.23, released 2019-06-09

Make it an error if your code does not parse with GHC

#662, don't warn on ($x), since it might not really be TH

#660, suggest tuple sections for \y -> (x,y) and similar

#667, warn on return x >> m and similar

#653, add symmetric versions of some == hints

#650, add a group of teaching hints

#651, warn on unused NamedFieldPuns

#646, switch to an HTML doctype

2.1.22, released 2019-05-25

#634, suggest modifyIORef ==> writeIORef when applicable

#642, suggest null in more places

#640, reenable GHC parsing

2.1.21, released 2019-05-19

#637, temporary workaround for GHC parser segfaults

2.1.20, released 2019-05-15

* Fix a dumb break in the API on parseModuleEx

2.1.19, released 2019-05-14

* Revert PVP breakage

2.1.18, released 2019-05-13

* Change parseModuleEx/ParseError by accident

#633, don't suggest changes inside RULES

#631, suggest typeOf ==> typeRep

Add matching on type variables

#627, restrict to GHC 8.4 and above

2.1.17, released 2019-04-17

#626, add operator wildcards with ?, ??, ??? etc

#625, fix an rnf/rhs typo

#562, make test --verbose show a list of matched hints

2.1.16, released 2019-04-15

Make `seq` and `rem` hints apply to prefix functions

#604, suggest rnf x `seq` () ==> rnf x

#619, require haskell-src-exts-util-0.2.5

#619, fix move guards forward with record puns

#618, add pure x <*> y ==> x <$> y

#611, add == and subst for more advanced match conditions

#612, add: Suggest f =<< instead of maybe Nothing f

#609, add code smells

#614, adds refactorings for camelCase and some list suggestions

#605, make command line arguments override the .yaml file

#603, QuasiQuotes can programatically use any extension

2.1.15, released 2019-02-27

#593, reorder guards in list comps where possible

#597, suggest pushing a map over a list comp inside

Say redundant pure, when the thing you are removing is pure

#554, add more verbosity

Don't test with GHC 7.4 to 7.8

#590, say which extensions should be deleted

#591, be careful about encoding on stdin

2.1.14, released 2019-01-28

#587, fix extensions implied by ImplicitParams

#588, suggest optional from attoparsec

2.1.13, released 2019-01-23

#583, suggest left sections to avoid lambdas

#580, remove redundant LANGUAGE pragmas which are implied by others

#575, add fixities for lattice

#564, fix hint around withFile with AppendMode

2.1.12, released 2018-12-10

Require haskell-src-exts-1.21

2.1.11, released 2018-12-02

#553, define __HLINT__=1 for the C preprocessor

#546, suggest `x $> y` for `const x <$> y`, `pure x <$> y`, and `return x <$> y`

#546, suggest `x <$ y` for `x <&> const y`, `x <&> pure y`, and `x <&> return y`

#556, disable a few incorrect lens hints

#545, don't suggest turning type applications into sections

#466, avoid false positives for Esqueleto

#535, more lens hints

Allow {-# HLINT #-} and {- HLINT -} pragmas

#532, generate requested report files even if there are no hints

#524, don't suggest newtype for existentials

#521, add a hint for f x@_ = ... ==> f x = ...

2.1.10, released 2018-08-16

#516, don't require a .hlint.yaml when running tests

Prefer .hlint.yaml to HLint.hs for settings

#513, add section links in the HTML report

2.1.9, released 2018-08-08

Add QuickCheck fixities

Warn on redundant EmptyCase extension

2.1.8, released 2018-07-06

#509, remove incorrect suggestions around sequence/pure

2.1.7, released 2018-07-03

#483, don't break quasi quotes when suggesting const

#404, remove the "Unnecessary hiding" hint introduced in #338

#162, make avoiding lambda with `infix` give a different name

#507, rename id x ==> x to redundant id

#286, improve the duplicate pragma message

#399, suggest (& f) ==> f

#136, don't suggest eta-reducing runST

#345, add catMaybes/fmap ==> mapMaybe

#345, add foldMap id ==> fold

#364, suggest >> instead of >>= \_ ->

#502, DeriveTraversable implies DeriveFoldable and DeriveFunctor

Add hints about fusing traverse/map

Better names for mapM/map fusion hints and others

#498, change the output to say "Perhaps:" rather than "Why not:"

2.1.6, released 2018-06-16

Match on explicit brackets at the root of a match expression

#470, suggest TupleSections

#496, suggest sequence/fmap ==> mapM

#473, warn on redundant void, _ <- and return ()

Make use of <$> more general, but in simpler cases

Warn about returns in the middle of do blocks

#471, suggest readTVarIO

#468, suggest using sortOn/Down

#458, document the restriction feature

#494, don't suggest newtype for unboxed tuples

#488, avoid warning about more test prefixes

2.1.5, released 2018-05-05

#478, take account of deriving strategies for extension use

#477, don't warn about unit_ as tasty-discover recommends it

2.1.4, released 2018-05-01

Don't warn about redundant $ for a $ b{c=d}

2.1.3, released 2018-04-18

Improve the performance of the camelCase hint

Don't suggest camelCase for record fields

Add a --timing flag to detect what is slow

2.1.2, released 2018-04-16

#407, don't error on unknown extensions on the command line

Require extra-1.6.6

#464, add more hints for concatMap

#462, ignore home directory when it isn't present

2.1.1, released 2018-03-24

#457, suggest turning on LambdaCase if necessary

#457, add RequiresExtension note

#454, add fixities for the HSpec `should*` functions

#455, add some more sequence hints

#453, allow pure in a few Monad hints as well as return

#451, add --with-group command line option

#424, suggest Foldable.forM_ in a few more places

#445, add suggestions for reader/state monad

#443, suggest join (x <$> y) ==> x =<< y

2.1, released 2018-02-07

* #433, make ideas span multiple modules/declarations

#433, allow ignoring statement-level duplication hint

#439, add more fixities for new base operators

#437, --json output should be finite

#425, avoid misparsing use of Gtk2Hs `on` function

#353, detect unused results from for/traverse/sequenceA

#428, add a few rules for the lens package

#429, spot restricted functions in infix operators

#427, don't eta reduce variables in the presence of quasi-quotes

Improve the HTML slightly

#416, add lens package fixities

2.0.15, released 2018-01-18

#426, don't suggest removing brackets for "x . (x +? x . x)"

#426, better results with haskell-src-exts-util-0.2.2

2.0.14, released 2018-01-14

#376, apply the "use fmap" hint in fewer places

#421, binaries available for OS X

2.0.13, released 2018-01-12

#376, suggest <$> instead of x <- foo; return $ f x

#401, suggest removing brackets for (f . g) <$> x

Add Semigroup instances

2.0.12, released 2017-12-12

Don't suggest Control.Arrow

Upgrade to haskell-src-exts-1.20

2.0.11, released 2017-11-30

#411, parse the YAML file with lots of HSE extensions turned on

#408, use the same config file logic in argsSettings as in hlint

Don't use unexported type synonyms in the public API

#405, fix false positives on MagicHash due to unboxed literals

2.0.10, released 2017-11-03

#377, suggest lambda case

Add CodeClimate support

#378, suggest map for degenerate foldr

#395, suggest x $> y from x *> pure y and x *> return y

#395, suggest x <$ y from pure x <* y and return x <* y

#393, suggest f <$> m from m >>= pure . f and pure . f =<<

#366, avoid the github API for prebuilt hlint, is rate limited

#352, suggest maybe for fromMaybe d (f <$> x)

#338, warn about things imported hidden but not used

#337, add --git flag to additionally check files in git

#353, suggest _ <- mapM to mapM_

#357, warn on unnecessary use of MagicHash

2.0.9, released 2017-06-13

#346, don't suggest explicit export lists

#344, fix the API so it works with hlint.yaml by default

2.0.8, released 2017-05-21

#342, add back support for - to mean stdin

2.0.7, released 2017-05-16

#340, fix for directory arguments in the .hlint.yaml

2.0.6, released 2017-05-08

Do statements are not redundant if they change an operator parse

#333, simplify labels on Parse error, makes it easier to ignore

2.0.5, released 2017-04-19

If the datadir is missing use data/ relative to the executable

Fix test mode to obey --datadir

2.0.4, released 2017-04-17

--default adds ignores for any warnings it finds

2.0.3, released 2017-04-12

#312, suggest removing the DeriveAnyClass extension

Suggest removing the DeriveLift extension

Remove redundant parts from list comprehensions, e.g. [a | True]

#326, fix up the bounds on the eta-reduce hint

2.0.2, released 2017-04-10

#323, try and avoid malformatted JSON

#324, use `backticks` in notes

#324, remove double escaping in note for --json

#322, fix the YAML syntax in default.yaml

2.0.1, released 2017-04-07

#320, still read ./HLint.hs if it exists

2.0, released 2017-04-06

#319, add a hint \x -> f <$> g x ==> fmap f . g

Don't say how many hints were ignored

Add a --default flag

#314, allow arguments in YAML configuration files

Add maybe False (== x) ==> (== Just x) hint, plus for /=

Remove the ability to pass the file on stdin using - as the file

Remove encoding from ParseFlags

Remove the --encoding/--utf8 options, always use UTF8

#311, suggest writeFile instead of withFile/hPutStr

#288, add configurable restrictions

Suggest using an export list on modules

Look for nearby .hlint.yaml files to supply configuration

Support YAML configuration files

#308, don't suggest newtype for unboxed types

Remove the import "hint" feature for hint inclusion

Builtin hints do not need to be imported, can only be ignored

Delete HLint2 API

#290, add hints suggesting traverse/traverse_

#303, detect unused OverloadedStrings extension

#302, detect unused TupleSections extension

1.9.41, released 2017-02-09

#299, warn in some cases when NumDecimals extension is unused

#300, warn when LambdaCase extension is unused

#301, when suggesting newtype remove strictness annotations

#297, better testing that there isn't a performance regression

#167, add -j flag for number of threads

#292, add fst/snd . unzip ==> map fst/snd

Don't suggest module export trick, breaks Haddock

1.9.40, released 2017-01-22

#293, fix the JSON format of the output

1.9.39, released 2016-12-04

#287, don't incorrectly suggest newtype

1.9.38, released 2016-11-24

#279, suggest newtype instead of data

#262, add rules to detect redundant castPtr calls

Detect unused TypeApplications extension

#277, don't enable TypeApplications extension by default

Allow haskell-src-exts-1.19

#276, remove multiple redundant parens in one go

#160, add a --only CLI option

#237, fix incorrect quasi quotes extension warning

#257, better bang pattern hints

1.9.37, released 2016-08-08

#255, don't suggest id @Int ==> @Int

#252, avoid clashes with GHCJS in the interim

1.9.36, released 2016-07-25

Require haskell-src-exts-1.18

#249, suggest avoiding elem on singletons

1.9.35, released 2016-06-10

#245, fix parse error reports

#243, update hlint.ghci to work with modern GHC

Require extra-1.4.9

1.9.34, released 2016-06-01

#154, fix some incorrect line numbers in literate Haskell

#161, fix literate Haskell and CPP

1.9.33, released 2016-05-30

#240, remove type-incorrect "on" hint

#234, warn about join seq

#232, suggest <|> instead of mplus in a few cases

1.9.32, released 2016-03-23

#53, require cpphs-1.20.1, has important fixes

#224, treat select $ specially, as per esqueleto conventions

#231, don't modify qualification on substitutions

#229, add void/mapM_/forM_ hints

1.9.31, released 2016-03-01

#222, don't suggest removing ~ if the Strict extension is on

1.9.30, released 2016-02-26

#220, fix incorrect hints of foldr/foldl on a tuple accumulator

1.9.29, released 2016-02-25

#219, add warnings about foldable methods on tuple

Put warnings before suggestions in the HTML report

1.9.28, released 2016-02-04

#215, spot newtype deriving inside classes

1.9.27, released 2016-02-01

#203, avoid recompiling everything twice

#213, don't suggest removing bang patterns on let

Rename HintStructure to HintPattern

#208, add an hlint function to the HLint3 API

#1, warn about unused DefaultSignatures extension

#137, add -XHaskell2010 and fix -XHaskell98

Allow checking even if a function has different arities

#193, don't warn on a -> (b -> c), it's sometimes sensible

#182, make parse errors severity Error

#181, warn on otherwise in a pattern variable

#163, eta reduce fun x = f $ x

#132, don't ever suggest liftM

#99, downgrade built in hints, Error => Warning => Suggestion

#99, add a Suggestion level severity

#207, make sure you close file handles

#205, add hint compare x y == EQ and /=

#204, add hint concatMap id ==> concat

#202, include refactorings is --json output

1.9.26, released 2016-01-02

#200, fix all lint warnings

#143, expose argsSettings

1.9.25, released 2015-11-24

#192, fix stdin output and --refactor

1.9.24, released 2015-11-22

#188, improve spotting redundant brackets around patterns

#138, reenable redundant where hint

1.9.23, released 2015-11-19

#184, require haskell-src-exts-1.17

#183, allow test_ as a prefix

1.9.22, released 2015-10-28

Don't suggest redundant lambda on view patterns

Add --no-exit-code flag

#174, don't suggest string literals

#175, disable 'rec' stealing extensions by default

#170, add hints for eta-reduced operators

#149, integrate a --refactor flag

#147, fix the -fglasgow-exts hint

#140, better name for moving brackets to eliminate $

Extra hints for <$>

Remove a redundant fmap hint

#131, add =<< rules in addition to >>=

1.9.21, released 2015-05-26

#130, ignore a BOM if it exists

#128, don't find files starting with . when searching directories

Suggest concat even if the [] is written ""

1.9.20, released 2015-04-21

#122, fix the zipWith/repeat hint

1.9.19, released 2015-03-26

#119, don't remove RecursiveDo if they use the rec statement

Add a suggestion concatMap/map ==> concatMap

1.9.18, released 2015-03-17

More GHC 7.10 warnings and build support

1.9.17, released 2015-02-25

#116, support hscolour-1.21

1.9.16, released 2015-01-09

#108, make "hlint ." work again

1.9.15, released 2015-01-03

#106, avoid warnings with GHC 7.10

#105, build with GHC 7.10

1.9.14, released 2014-12-24

#649, don't suggest const for values using RecordWildCards

1.9.13, released 2014-11-30

#97, remove the encoding bits of the API

#98, add an HLint3 prototype API

#93, make the --quickcheck tests work on GHC 7.8

Add --tempdir flag to the test mode

1.9.12, released 2014-11-09

#96, fix the --utf8 flag

Make Encoding an alias for TextEncoding

Default to UTF8 encoding

1.9.11, released 2014-11-07

#95, don't suggest camel case for names containing digits

Add a dependency on the extra package

#92, use a new way for determining the color default

Add a dependency on ansi-terminal

1.9.10, released 2014-10-19

Spot unsafePerformIO without NOINLINE

1.9.9, released 2014-10-13

#89, fix compiling the executable with --flag=-gpl

1.9.8, released 2014-10-08

#82, don't crash on XmlHybrid modules

#88, allow avoiding HsColour, as it is GPL licensed

#87, don't push if down, since it can be type incorrect

1.9.7, released 2014-10-02

#86, don't use color unless $TERM claims to support it

1.9.6, released 2014-09-30

#85, fix the free variable matching check for lambda

#84, suggest fmap for Either

Make --json put each hint on a different line

Support -X for extensions to the hse mode

1.9.5, released 2014-09-14

Remove support for GHC 7.2

Upgrade to haskell-src-exts-1.16

1.9.4, released 2014-08-27

#81, fixes for GHC 7.9

#78, add hints for list patterns

#72, make --color the default on Linux

1.9.3, released 2014-07-28

#73, fix multithreading and exceptions

1.9.2, released 2014-07-23

#68, add --no-summary

1.9.1, released 2014-07-21

#65, add flip (>>=) ==> (=<<) and the reverse

#61, add --json flag

1.9, released 2014-06-30

Remove not (isControl x) ==> isPrint (not true for '\173')

#57, warn on invalid pragmas

Make the API pass and require comments

#59, make sure qualified operators match properly

Rename notTypeSafe annotation to noTypeCheck

Remove an invalid rule suggesting tanh

#13, add a --quickcheck flag to test the hints

Add --typecheck flag to test mode to type check the hints

Remove incorrect for intercalate to unlines

#37, remove incorrect hint for isAlphaNum

#45, add mapMaybe id ==> catMaybes

#42, add some repeat hints

1.8.61, released 2014-04-14

#40, allow haskell-src-exts-1.15

Don't detect redundant Generics extension

1.8.60, released 2014-04-02

#33, add --cpp-file to preinclude a file

#34, add back --quiet flag

#639, don't suggest evaluate, because not all Monad's are IO

#31, delete the elem/notElem hints

#30, remove weird "free module" matching

#15, add prototype grep mode

Change to make test a separate mode

#12, more list based suggestions

#637, turn off QuasiQuotes by default

1.8.59, released 2014-03-13

#27, fix up directory file searching

1.8.58, released 2014-03-11

Move the API to Language.Haskell.HLint2

#638, ensure $! doesn't break strictness with strict fields

#24, don't remove DeriveFunctor even when only on a newtype

#22, turn off UnboxedTuples by default

#21, strip /* C style */ comments

#635 and #18, require cpphs-1.18.1

Switch to CmdArgs for command line parsing

Remove -x as a synonym for --cross

1.8.57, released 2014-02-04

#6, add a preview of an API

#331, improve parse error locations for literate Haskell

1.8.56, released 2014-01-30

Remove support for GHC 6.12 and below

#317, tone down the void hint

#16, match not . not (and reverse . reverse etc)

Suggest <$> instead of fmap f $ ...

Tweak some priorities, make >=> a warn and void an error

#3, make top of the file ANN pragmas work

#10, add a suggestion to use unlines

#11, add a few hints about characters

#8, add CHANGES.txt to the Cabal package

1.8.55, released 2013-11-29

#627, fix the UnboxedTuples extension warning

1.8.54, released 2013-11-28

Fix a bug when suggesting const

1.8.53, released 2013-09-24

Fix some corner cases when suggesting foldr etc.

#517, don't introduce new free variables in a replacement

1.8.52, released 2013-09-24

#2, Generic is not newtype derivable

1.8.51, released 2013-08-20

Upgrade to haskell-src-exts-1.14

1.8.50, released 2013-08-18

Eliminate upper bounds on all dependencies

#617, fix up notIn to take account of Template Haskell variables

#573, suggest removing various deriving language extensions

1.8.49, released 2013-07-23

Remove ^^ ==> ** hint

Remove a duplicate sqrt hint

Ensure that --test failures throws an error

Fix up the copyright year in --help

1.8.48, released 2013-07-16

Brackets at the root of annotations are fine

Reduce a few more lambda expressions

1.8.47, released 2013-06-28

#613, compatibility with base-4.7

1.8.46, released 2013-06-06

Remove incorrect isPrefixOf hints

#586, add span/break/takeWhile/dropWhile hints

#588, add sort/reverse hints

#601, add replicate/map/repeat hints

Add a hint about reverse/reverse

Add side as an alias for _

Add hint as an alias for error

1.8.45, released 2013-05-12

#600, hints for unnecessary lazy annotations

1.8.44, released 2013-04-21

#598, warn on unnecessary bang patterns

1.8.43, released 2013-01-27

Change some hint error/warning levels

1.8.42, released 2013-01-23

Allow cpphs-1.16

1.8.41, released 2013-01-19

#586, add a rule for takeWhile/dropWhile ==> span

#522, add hints for the state monad

#499, fix up the test suite

Fix the side conditions for the `isPrefixOf` hint

Add hints about take/drop on non positive numbers

Add isNat/isPos/isNeg/isNegPos as notes

Make the notes a structured type

Add --proof feature

Retire the Prelude.catch hint

Additional boolean equality hints

1.8.40, released 2013-01-06

#585, lots of additional list based hints

1.8.39, released 2012-12-06

#582, don't suggest renaming with trailingHashes#

#578, treat _ bindings differently in lambdas

1.8.37, released 2012-12-01

#575, allow cpphs-1.15

1.8.36, released 2012-11-27

Make --with imply no default Hint files

1.8.35, released 2012-11-17

#567, avoid duplicate hints around (.) hints

1.8.34, released 2012-11-06

Switch license from GPL to BSD3

1.8.33, released 2012-10-23

Lots more hints on laziness, foldable and a few others

Use mapM_ etc in more situations, when using explicit >>=

1.8.32, released 2012-10-23

Add notes about how to deal with imported fixites

Add a --with flag for passing settings on the command line

#563, make sure TypeSig hints get the right function name

Update the copyright year to 2012

#564, allow brackets and type signatures on annotations

Add a note that about using !! if the index is negative

1.8.31, released 2012-08-18

Avoid incomplete patterns when reading ANN pragmas

#555, top-level expressions require TemplateHaskell

1.8.30, released 2012-07-11

Add elemIndex/elemIndices hints

Allow cpphs-1.14

#551, allow case_ as a name with an underscore

1.8.29, released 2012-06-01

Allow hscolor-1.20.*

#574, add a hint to for mapM/zip ==> zipWithM

1.8.28, released 2012-04-01

Fix a bug, >=> hint was missing check about removal of free var

1.8.27, released 2012-03-30

Allow haskell-src-exts-1.13.*

1.8.26, released 2012-03-27

Allow haskell-src-exts-1.12.*

Don't suggest redundant brackets when turning ++ into :

Add hints suggesting >=> and <=<

1.8.25, released 2012-03-25

Update the copyright year in the Cabal file

Allow transformers-0.3.*

1.8.24, released 2012-02-20

#531, Make hlint.ghci well formed again

1.8.23, released 2012-02-05

Add hints for redundant seq/evaluate using isWHNF

#526, don't hint for return $! (x :: Int)

1.8.22, released 2012-02-04

Add hint for $! where the RHS is not a variable

1.8.21, released 2012-01-26

#508, add lots of hints from the base library

#317, add hints for a >> return () to void

Add a fromMaybe/fmap ==> maybe hint

#304, don't backet tuple sections

Add foldl (++) [] ==> concat

#512, detect unnecessary case construct

When finding hints, don't abort on a parse error

#507, add exitSuccess hint

#505, suggest record patterns

1.8.20, released 2011-11-29

#500, make sure eta reduction has position information

1.8.19, released 2011-11-27

#498, eta reduce even if there is a where block

#497, don't produce an incorrect lambda when suggesting flip

1.8.18, released 2011-11-05

#438, use Foo.Bar to mean Foo/Bar.hs

Add a --path command line option to say where files live

#441, avoid bad matches due to automatically eta reducing rules

#489, import Foo as Foo is redundant

#481, suggest liftM instead of fmap when using the Monad laws

1.8.17, released 2011-10-01

#479, allow - as the file to specify using stdin

1.8.16, released 2011-09-28

#478, allow cpphs-1.13.1

Never suggest view patterns (they aren't sufficiently better)

Don't suggest use of Data.Ord.comparing, using `on` is better

Only suggest elem/notElem on 3 or more items

1.8.15, released 2011-08-13

Add --cpp-ansi to turn on ANSI compat in cpphs

1.8.14, released 2011-08-12

#455, GHC 7.2 compatibility

Add lots of hints from Lennart Augustsson

1.8.13, released 2011-07-05

#302, add a backup fixity analysis, if the HSE one fails

Fix x /= y || x /= z ==> x `notElem` [y,z], should be &&

1.8.12, released 2011-07-03

Allow cpphs-1.12

1.8.11, released 2011-06-18

#440, suggest removing redundant brackets under do

#439, don't add redundant brackets under do

1.8.10, released 2011-06-12

Upgrade to hscolour-1.19

1.8.9, released 2011-05-26

#436, add a hint about mapMaybe/map

Upgrade to haskell-src-exts-1.11.1

Add a --cross flag, to detect hints between multiple modules

#428, don't suggest using String in an instance head

1.8.8, released 2011-04-03

#384, suggest collapsing multiple imports/exports

#374, don't suggest the removal of necessary brackets

#337, suggest Control.Exception.catch instead of Prelude.catch

#412, add hints based on Control.Exception

#378, suggest removing fromInteger/fromIntegral on literals

#369, add notes to a few hints about possible pitfalls

#409, fix a few cases where definitions suggested themselves

#410, Support test* as ignored items in settings files

#414, add isLit* pattern, and hint about ^^ ==> **

#420, make the suggestion to use let a warning

#408, rework the when/unless hints, don't suggest on itself

Add duplicate detector, for copy/pasted code

#285, don't show duplicate filepath separators

If the user enters directories containing no files then say

Make suggesting curry/uncurry a warning instead of an error

1.8.7, released 2011-01-31

Relax the transformers dependency, works with 0.0.* and 0.1.*

1.8.6, released 2011-01-27

Export suggestionSeverity/Severity from the API

Allow hint imports with "hlint", as well as the existing "hint"

1.8.5, released 2011-01-23

Update the copyright year to 2011

#400, support more encoding strings, give useful errors

#401, rename the report template to report_template.html

Replace filter f x /= [] with any f x, and 2 more similar

1.8.4, released 2011-01-12

#308, allow haskell-src-exts-1.10.1, which parses Unicode better

import qualified Char ==> import qualified Data.Char as Char

#393, fix suggestion for import IO, requires more than System.IO

#376, note that RecordWildCards implies DisambiguateRecordFields

1.8.3, released 2010-11-10

Allow uniplate-1.6

Switch from mtl to transformers

#373, require haskell-src-exts-1.9.6

Add a type signature for GHC 7

Suggest [x | x <- xs] ==> xs, if x is a variable

1.8.2, released 2010-10-23

#371, foo (\x -> y :: Int -> Int) is not a redundant bracket

Add a hint to use just equality rather than isJust/fromJust

1.8.1, released 2010-10-15

Massive speed up for files with many naming hints

#361, keep module names when suggesting infix

Add support for wildcard matching on module names

#357, don't camel case suggest on FOO_A

#370, fix building with GHC 6.10.4

#313, upgrade to haskell-src-exts-1.9.4

Workaround for #358, disable empty where hints

#355, make "--ignore=Parse error" work

Add --cpp-simple to run a simple CPP to strip lines begining #

Add bracketing information if the parent is a case

Suggest intercalate

1.8, released 2010-09-11

Make --test --hint=file typecheck a file for valid hints

#347, Suggest use of otherwise, instead of True, in pattern guards

Add hints about redundant where statements

Suggest removal of redundant guards

Make hints about guards work on patterns/infix matches/case alts

Make finding guards look a child functions

Correctly collapse functions and lambdas using the same patterns

Suggest promoting patterns bound to lambdas to functions

Allow collapsing lambdas sharing pattern variables correctly

#344, only give one warning for multiple collapsable lambdas

#300, substantially improve module name resolution with imports

BREAKING: imports in hint files require import "hint" HintFile

#335, redundant id should only generate one warning

Add a hint for using map (f &&& g)

#328, for foo'bar suggest the naming fooBar

#323, detect redundant brackets in field declarations

#321, force the whole file before displaying a parse error

Make --find more robust, fixes a potential parse error

1.7.3, released 2010-07-25

Upgrade to hscolour-1.17

1.7.2, released 2010-06-11

#318, match rules by expanding out (.)

#319, don't remove lambdas on the right of infix operators

1.7.1, released 2010-06-07

Add a --quiet flag, to supress stdout (mainly for API users)

1.7, released 2010-06-06

Add support for HLint.Builtin.All

Fix crash on (\x -> x)

Make the library correctly honour the data directory

Improve the manual, mainly language changes and hyperlinking

Fix a bug in ListRec, could have _recursive_ in the result

#315, spot list rec hints through $ and let

Add hints based on (f $) ==> f, and change in ListRec hints

Changes to the lambda suggestions, now gives a few more hints

Don't suggest importing modules in old-locale/old-time

Make the API return the suggestions, rather than just the count

#278, add -XNoCpp to disable the C preprocessor

#279, add -XExt/-XNoExt to choose extensions

Remove some redundant brackets in type replacements

#286, remove redundant brackets in match

Additional bracket removal, application under sections

#299, rework hints to use flip (suggest infix in some cases)

Add some fromMaybe hints

Fix bug where hints didn't always get names

#306, make --find use the hints if there are files specified

Upgrade to haskell-src-exts-1.9

#303, allow fixities to be specified in hint files

1.6.21, released 2010-04-07

#287, warn about Haskell 98 imports

#297, add a hint to use mplus

#288, detect redundant brackets under a lambda

#302, remove error about ambiguous fixities

#281, enhance the redundant monad return warnings

#293, eliminate _noParen_ from the result

#284, eliminate ViewPatterns from FindHints, hits compiler bug

#283, don't suggest removal of RecordWildCards

Add some hints about concat and (++)

#273, require haskell-src-exts >= 1.8.2

1.6.20, released 2010-02-10

#275, add more acknowledgements (still very incomplete)

#254, remove the foldr1/map hint

Compress nested lambdas, \x -> \y -> ... ==> \x y -> ...

Fix minor bug on \x -> \x -> foo x x

#274, add redundant bracket inside record update/construct

#272, don't mess up creating sections from qualified names

Add some hints to suggest elem

Add Paths_hlint to the .cabal file, or the library doesn't link

#271, rewrite the match engine in terms of SYB

1.6.19, released 2010-02-06

#251, add automatic definition hunting with --find