git.iko.soy/typeable/validationt
on dafd336 help sign in
.travis.ymldeleted−38
since splitsnapshots
unifiedsplit
@@ -1,38 +0,0 @@
1−sudo: true
2−language: haskell
3−
4−git:
5− depth: 5
6−
7−cache:
8− directories:
9− - "$HOME/.cabal/store"
10− - "$HOME/.stack"
11− - "$TRAVIS_BUILD_DIR/.stack-work"
12−
13−jobs:
14− include:
15− - ghc: 8.10.2
16− env: SNAPSHOT="nightly-2020-11-03"
17− - ghc: 8.8.4
18− env: SNAPSHOT="lts-16.20"
19− - ghc: 8.6.5
20− env: SNAPSHOT="lts-14.22"
21− - ghc: 8.4.4
22− env: SNAPSHOT="lts-12.26"
23−
24−install:
25− - |
26− # install stack
27− curl -sSL https://get.haskellstack.org/ | sh
28−
29− # build project with stack
30− stack --version
31− stack build --system-ghc --test --bench --no-run-tests --no-run-benchmarks --resolver=$SNAPSHOT
32−
33−script:
34− - |
35− stack test --system-ghc
36−
37−notifications:
38− email: false
ChangeLog.md+2−16
@@ -1,19 +1,5 @@
1# Revision history for validationt
1# Revision history for validationt
2
2
3−## 0.3.0
3+## 0.1.0.0 -- YYYY-mm-dd
4
4
5−* Added documentation.
5+* First version. Released on an unsuspecting world.
6−* Fixed `textErrors` behaviour.
7−* Dropped `transformers-lift` dependency.
8−
9−## 0.2.1.0
10−
11−* GHC 8.4 support
12−
13−## 0.2.0.0
14−
15−* Fixes
16−
17−## 0.1.0.0
18−
19−* Initial release
README.mddeleted−76
@@ -1,76 +0,0 @@
1−![Travis CI Badge](https://img.shields.io/travis/typeable/validationt)
2−
3−# ValidationT
4−
5−A simple data validation library. The main idea is to provide an easy way to
6−validate web form data by aggregating errors for each field.
7−
8−## Usage
9−
10−Suppose you want to validate some data from the user. Say, that the password adheres to some rules.
11−
12−You might do something like this:
13−
14−```haskell
15−validatePassword :: Monad m => String -> ValidationT [String] m ()
16−validatePassword password = do
17− vLength password
18− vAlpha password
19− vNum password
20− where
21− vLength p = when (length p < 8)
22− $ vWarning ["The password should be at least 8 characters long."]
23− vAlpha p = unless (any isAlpha p)
24− $ vWarning ["The password should contain at least one alphabetic character."]
25− vNum p = unless (any isDigit p)
26− $ vWarning ["The password should contain at least one numeric character."]
27−```
28−
29−`ValidationT e m a` essentially just gathers the errors thrown by `vWarning`.
30−
31−```haskell
32−vWarning :: (Monad m, Monoid e) => e -> ValidationT e m ()
33−```
34−
35−`vWarning` `mappend`s the given `e` to the already collected errors. This is why the warnings are contained inside a list.
36−
37−There is also `vError`. The only difference between `vWarning` and `vError` is that `vError` stops further execution (and further collection of errors and warnings).
38−
39−You would use the validation like this:
40−
41−```haskell
42−main :: IO ()
43−main = do
44− password <- getLine
45− result <- runValidationTEither . validatePassword $ password
46− putStrLn $ case result of
47− Left errs -> unlines err
48− Right () -> "You are fine."
49−```
50−
51−You could, of course, do more complicated things like use `vWarningL` and `vErrorL` to add an error to a `mempty` structure, which gets `mappend`ed with other errors.
52−
53−The library comes with a `MonoidMap` `newtype` wrapper around `Map`, which `mappend`s the values themselves on conflict. This can be useful if you have a multiple points of failure and you want to distinguich between them -- validating a username and a password for example:
54−
55−```haskell
56−data Piece
57− = Password
58− | UserName
59− deriving (Eq, Show, Ord)
60−
61−validatePassword :: Monad m => String -> ValidationT (MonoidMap Piece [String]) m ()
62−validatePassword password = do
63− vLength password
64− vAlpha password
65− vNum password
66− where
67− warning = mmSingleton UserName
68− vLength p = when (length p < 8)
69− $ warning ["The password should be at least 8 characters long."]
70− vAlpha p = unless (any isAlpha p)
71− $ warning ["The password should contain at least one alphabetic character."]
72− vNum p = unless (any isDigit p)
73− $ warning ["The password should contain at least one numeric character."]
74−```
75−
76−(`mmSingleton` is a covenience initializer for `MonoidMap`.)
src/Control/Monad/Validation.hs+39−187
@@ -1,77 +1,37 @@
1−{-# LANGUAGE CPP #-}
1+module Common.Monad.Validation where
2−{-# LANGUAGE GeneralizedNewtypeDeriving #-}
3−{-# LANGUAGE OverloadedStrings #-}
4−{-# LANGUAGE TemplateHaskell #-}
5−{-# LANGUAGE TypeFamilies #-}
6−{-# LANGUAGE UndecidableInstances #-}
7
2
8−module Control.Monad.Validation
9− ( ValidationT(..)
10− , runValidationT
11− , runValidationTEither
12− , handleValidationT
13− , vError
14− , vWarning
15− , vErrorL
16− , vWarningL
17− , vZoom
18− , vZoomL
19− , vPromote
20− , mmSingleton
21− , setMempty
22− , neConcat
23− , textErrors
24− , _MonoidMap
25− , MonoidMap(..)
26− ) where
27−
28−import Control.Applicative
29import Control.Lens hiding ((.=))
3import Control.Lens hiding ((.=))
30import Control.Monad.Base
4import Control.Monad.Base
31import Control.Monad.Catch
5import Control.Monad.Catch
32import Control.Monad.Except
6import Control.Monad.Except
33−import Control.Monad.Fail
34import Control.Monad.State.Strict
7import Control.Monad.State.Strict
35−import Control.Monad.Trans.Control
8+import Control.Monad.Trans.Lift.Local
36import Data.Aeson
9import Data.Aeson
37import Data.Foldable as F
10import Data.Foldable as F
38−import Data.Functor
39import Data.List as L
11import Data.List as L
40import Data.Map.Strict as M
12import Data.Map.Strict as M
13+import Data.Monoid
41import Data.Text as T
14import Data.Text as T
42import Data.Vector as V
15import Data.Vector as V
43import Test.QuickCheck
16import Test.QuickCheck
44
17
45−#if MIN_VERSION_mtl(2,3,0)
46−import Control.Monad
47−import Control.Monad.Fix
48−#endif
49−
50−-- | Collects all thrown warnings in 'StateT' and errors
18+-- | Collects all throwed "warnings" throwed through StateT and "errors" throwed
51−-- in 'ExceptT' into a single value using 'Monoid'.
19+-- through ExceptT to single value using Monoid
20+-- FIXME: give more instances like HReaderT and MonadBaseControl/MonadMask
52newtype ValidationT e m a = ValidationT
21newtype ValidationT e m a = ValidationT
53 { unValidationT :: ExceptT e (StateT e m) a
22 { unValidationT :: ExceptT e (StateT e m) a
54 } deriving ( Functor, Applicative, Monad, MonadThrow, MonadCatch
23 } deriving ( Functor, Applicative, Monad, MonadThrow, MonadCatch
55− , MonadBase b, Alternative, MonadFix, MonadFail, Contravariant
24+ , MonadBase b )
56− , MonadIO, MonadPlus, MonadBaseControl b, MonadMask )
57
25
58instance MonadTrans (ValidationT e) where
26instance MonadTrans (ValidationT e) where
59 lift = ValidationT . lift . lift
27 lift = ValidationT . lift . lift
60
28
29+instance LiftLocal (ValidationT e) where
30+ liftLocal _ l f = ValidationT . mapExceptT (mapStateT $ l f) . unValidationT
31+
61-- | Map with 'Monoid' instance which 'mappend' its values
32-- | Map with 'Monoid' instance which 'mappend' its values
62−--
63−-- This can be used as the `e` in `ValidationT e m a` to provide different
64−-- sets of errors and warnings for different keys.
65−--
66−-- >>> :{
67−-- mconcat
68−-- [ MonoidMap $ M.fromList [(1, "foo"), (2, "hello, "), (3, "oh no")]
69−-- , MonoidMap $ M.fromList [(1, "bar"), (2, "world")]
70−-- ]
71−-- :}
72−-- MonoidMap (fromList [(1,"foobar"),(2,"hello, world"),(3,"oh no")])
73newtype MonoidMap k v = MonoidMap (Map k v)
33newtype MonoidMap k v = MonoidMap (Map k v)
74− deriving (Eq, Ord, Show, Arbitrary, Foldable)
34+ deriving (Eq, Ord, Show, Arbitrary)
75
35
76makePrisms ''MonoidMap
36makePrisms ''MonoidMap
77
37
@@ -82,14 +42,10 @@ instance (Ord k) => Ixed (MonoidMap k v) where
82instance (Ord k) => At (MonoidMap k v) where
42instance (Ord k) => At (MonoidMap k v) where
83 at key = _MonoidMap . at key
43 at key = _MonoidMap . at key
84
44
85−#if MIN_VERSION_base(4,11,0)
86−instance (Ord k, Semigroup v) => Semigroup (MonoidMap k v) where
87− (<>) = mmAppend
88−#endif
89−
90instance (Ord k, Monoid v) => Monoid (MonoidMap k v) where
45instance (Ord k, Monoid v) => Monoid (MonoidMap k v) where
91 mempty = MonoidMap M.empty
46 mempty = MonoidMap M.empty
92− mappend = (<>)
47+ mappend (MonoidMap a) (MonoidMap b) =
48+ MonoidMap $ M.unionWith (<>) a b
93
49
94instance (ToJSON k, ToJSON v) => ToJSON (MonoidMap k v) where
50instance (ToJSON k, ToJSON v) => ToJSON (MonoidMap k v) where
95 toJSON (MonoidMap m) = toJSON $ L.map toObj $ M.toList m
51 toJSON (MonoidMap m) = toJSON $ L.map toObj $ M.toList m
@@ -99,7 +55,7 @@ instance (ToJSON k, ToJSON v) => ToJSON (MonoidMap k v) where
99 , "value" .= v ]
55 , "value" .= v ]
100
56
101instance (Ord k, FromJSON k, FromJSON v) => FromJSON (MonoidMap k v) where
57instance (Ord k, FromJSON k, FromJSON v) => FromJSON (MonoidMap k v) where
102− parseJSON = withArray "MonoidMap" go
58+ parseJSON v = withArray "MonoidMap" go v
103 where
59 where
104 go arr = do
60 go arr = do
105 keyvals <- traverse fromObj arr
61 keyvals <- traverse fromObj arr
@@ -109,67 +65,35 @@ instance (Ord k, FromJSON k, FromJSON v) => FromJSON (MonoidMap k v) where
109 val <- obj .: "value"
65 val <- obj .: "value"
110 return (key, val)
66 return (key, val)
111
67
112−#if MIN_VERSION_base(4,11,0)
113−mmAppend :: (Ord k, Semigroup v) => MonoidMap k v -> MonoidMap k v -> MonoidMap k v
114−#else
115−mmAppend :: (Ord k, Monoid v) => MonoidMap k v -> MonoidMap k v -> MonoidMap k v
116−#endif
117−mmAppend (MonoidMap a) (MonoidMap b) = MonoidMap $ M.unionWith (<>) a b
118−
119−-- | Convenient for 'vZoom' as first argument. Will prevent generation
68+-- | Convenient for 'vZoom' as first artument. Will prevent generation
120−-- of map with 'mempty' values.
69+-- of map with 'mempty' values
121mmSingleton :: (Eq v, Monoid v, Ord k) => k -> v -> MonoidMap k v
70mmSingleton :: (Eq v, Monoid v, Ord k) => k -> v -> MonoidMap k v
122−mmSingleton k v
123− | v == mempty = mempty
124− | otherwise = MonoidMap . M.singleton k $ v
71+mmSingleton k = memptyWrap mempty $ MonoidMap . M.singleton k
125
72
126−-- | Sets given value to 'mempty'.
73+-- | Set given value to 'mempty'
127setMempty :: (Monoid s) => ASetter' s a -> a -> s
74setMempty :: (Monoid s) => ASetter' s a -> a -> s
128setMempty setter a = set setter a mempty
75setMempty setter a = set setter a mempty
129
76
130−neConcat :: Foldable f => (a -> a -> a) -> f a -> Maybe a
77+memptyWrap :: (Eq a, Monoid a) => b -> (a -> b) -> a -> b
131−neConcat f a
78+memptyWrap b f a
132− | F.null a = Nothing
79+ | a == mempty = b
133− | otherwise = Just $ F.foldr1 f a
80+ | otherwise = f a
81+
82+-- | If given container is not 'mempty', then use given function to
83+-- append all its elements and return 'Just' result
84+neConcat
85+ :: (Foldable f, Eq (f a), Monoid a, Monoid (f a))
86+ => (a -> a -> a)
87+ -> f a
88+ -> Maybe a
89+neConcat f = memptyWrap Nothing (Just . F.foldl' f mempty)
134
90
135−-- | Returns the strings, concatanated with @", "@ if the list is not empty.
136−--
137−-- Returns Nothing if the list is empty
138−--
139−-- >>> textErrors ["foo", "bar"]
140−-- Just "foo, bar"
141−--
142−-- >>> textErrors ["foo"]
143−-- Just "foo"
144−--
145−-- >>> textErrors []
146−-- Nothing
147textErrors :: [Text] -> Maybe Text
91textErrors :: [Text] -> Maybe Text
148textErrors = neConcat (\a b -> a <> ", " <> b)
92textErrors = neConcat (\a b -> a <> ", " <> b)
149
93
150−-- | Returns 'mempty' instead of error if no warnings have occurred.
94+-- | Returns `mempty` instead of error if no warnings was occured. So, your
95+-- error should have `Eq` instance to detect that any error was occured. Returns
151−-- Returns 'Nothing' as the second element of tuple if computation was
96+-- Nothing for second element of tuple if compuration was interruped by 'vError'
152−-- interrupted by 'vError'.
153−--
154−-- Returns all concatenated errors and warnings and the result if no
155−-- errors have occurred (warnings could have occurred).
156−--
157−-- >>> :{
158−-- runValidationT $ do
159−-- vWarning ["warning1"]
160−-- vError ["error"]
161−-- vWarning ["warning2"]
162−-- return 8
163−-- :}
164−-- (["error","warning1"],Nothing)
165−--
166−-- >>> :{
167−-- runValidationT $ do
168−-- vWarning ["warning1"]
169−-- vWarning ["warning2"]
170−-- return 8
171−-- :}
172−-- (["warning1","warning2"],Just 8)
173runValidationT :: (Monoid e, Monad m) => ValidationT e m a -> m (e, Maybe a)
97runValidationT :: (Monoid e, Monad m) => ValidationT e m a -> m (e, Maybe a)
174runValidationT (ValidationT m) = do
98runValidationT (ValidationT m) = do
175 (res, warnings) <- runStateT (runExceptT m) mempty
99 (res, warnings) <- runStateT (runExceptT m) mempty
@@ -177,25 +101,6 @@ runValidationT (ValidationT m) = do
177 Left err -> (err <> warnings, Nothing)
101 Left err -> (err <> warnings, Nothing)
178 Right a -> (warnings, Just a)
102 Right a -> (warnings, Just a)
179
103
180−-- | Like 'runValidationT' but doesn't return the result
181−-- if any warning has occurred.
182−--
183−-- >>> :{
184−-- runValidationTEither $ do
185−-- vWarning ["warning1"]
186−-- vError ["error"]
187−-- vWarning ["warning2"]
188−-- return 8
189−-- :}
190−-- Left ["error","warning1"]
191−--
192−-- >>> :{
193−-- runValidationTEither $ do
194−-- vWarning ["warning1"]
195−-- vWarning ["warning2"]
196−-- return 8
197−-- :}
198−-- Left ["warning1","warning2"]
199runValidationTEither
104runValidationTEither
200 :: (Monoid e, Eq e, Monad m)
105 :: (Monoid e, Eq e, Monad m)
201 => ValidationT e m a
106 => ValidationT e m a
@@ -206,71 +111,28 @@ runValidationTEither action = do
206 Just a | err == mempty -> Right a
111 Just a | err == mempty -> Right a
207 _ -> Left err
112 _ -> Left err
208
113
209−-- | Like 'runValidationTEither', but takes an error handler instead of
210−-- returning errors and warnings.
211−--
212−-- >>> :{
213−-- handleValidationT (\_ -> return 11) $ do
214−-- vWarning ["warning1"]
215−-- vError ["error"]
216−-- vWarning ["warning2"]
217−-- return 8
218−-- :}
219−-- 11
220−--
221−-- >>> :{
222−-- handleValidationT (\_ -> return 11) $ do
223−-- vWarning ["warning1"]
224−-- vWarning ["warning2"]
225−-- return 8
226−-- :}
227−-- 11
228handleValidationT
114handleValidationT
229 :: (Monoid e, Monad m, Eq e)
115 :: (Monoid e, Monad m, Eq e)
230 => (e -> m a)
116 => (e -> m a)
231 -> ValidationT e m a
117 -> ValidationT e m a
232 -> m a
118 -> m a
233−handleValidationT handler action =
119+handleValidationT handler action = do
234 runValidationTEither action >>= either handler return
120 runValidationTEither action >>= either handler return
235
121
236−-- | Stops further execution and appends the given error.
122+-- | Stops further execution of validation
237vError :: (Monad m) => e -> ValidationT e m a
123vError :: (Monad m) => e -> ValidationT e m a
238vError e = ValidationT $ throwError e
124vError e = ValidationT $ throwError e
239
125
240−-- | Does not stop further execution and appends the given warning.
126+-- | Does not stop further execution, append warning to
241vWarning :: (Monad m, Monoid e) => e -> ValidationT e m ()
127vWarning :: (Monad m, Monoid e) => e -> ValidationT e m ()
242vWarning e = ValidationT $ modify' (<> e)
128vWarning e = ValidationT $ modify' (<> e)
243
129
244−-- | Like 'vError' but allows you to use a setter to insert an error somewhere
245−-- deeper into an empty ('mempty') "e" from "ValidationT e m x", which is then
246−-- combined with all gathered warnings.
247vErrorL :: (Monad m, Monoid e) => ASetter' e a -> a -> ValidationT e m x
130vErrorL :: (Monad m, Monoid e) => ASetter' e a -> a -> ValidationT e m x
248vErrorL l a = vError $ setMempty l a
131vErrorL l a = vError $ setMempty l a
249
132
250−-- | Like 'vWarning' but allows you to use a setter to insert an error somewhere
251−-- deeper into an empty ('mempty') "e" from "ValidationT e m x", which is then
252−-- combined with all gathered warnings.
253vWarningL :: (Monad m, Monoid e) => ASetter' e a -> a -> ValidationT e m ()
133vWarningL :: (Monad m, Monoid e) => ASetter' e a -> a -> ValidationT e m ()
254vWarningL l a = vWarning $ setMempty l a
134vWarningL l a = vWarning $ setMempty l a
255
135
256−-- | Allows you apply a transformation to the "e" in "ValidationT e m x".
257−--
258−-- >>> :{
259−--runValidationT . vZoom (Data.Map.singleton "password errors") $ do
260−-- vWarning ["warning1"]
261−-- vError ["error"]
262−-- vWarning ["warning2"]
263−-- return 8
264−-- :}
265−-- (fromList [("password errors",["error","warning1"])],Nothing)
266−--
267−-- >>> :{
268−-- runValidationT . vZoom (Data.Map.singleton "password errors") $ do
269−-- vWarning ["warning1"]
270−-- vWarning ["warning2"]
271−-- return 8
272−-- :}
273−-- (fromList [("password errors",["warning1","warning2"])],Just 8)
274vZoom
136vZoom
275 :: (Monad m, Monoid a, Monoid b)
137 :: (Monad m, Monoid a, Monoid b)
276 => (a -> b)
138 => (a -> b)
@@ -280,21 +142,11 @@ vZoom up action = do
280 (err, res) <- lift $ runValidationT action
142 (err, res) <- lift $ runValidationT action
281 case res of
143 case res of
282 Nothing -> vError $ up err
144 Nothing -> vError $ up err
283− Just a -> vWarning (up err) $> a
145+ Just a -> vWarning (up err) *> return a
284
146
285−-- | Like 'vZoom' but takes a setter instead of a function.
286vZoomL
147vZoomL
287 :: (Monad m, Monoid a, Monoid b)
148 :: (Monad m, Monoid a, Monoid b)
288 => ASetter' b a
149 => ASetter' b a
289 -> ValidationT a m x
150 -> ValidationT a m x
290 -> ValidationT b m x
151 -> ValidationT b m x
291−vZoomL l = vZoom (setMempty l)
152+vZoomL l action = vZoom (setMempty l) action
292−
293−-- | Turn any warnings the have occurred into errors.
294−vPromote
295− :: (Monad m, Monoid a, Eq a)
296− => ValidationT a m x
297− -> ValidationT a m x
298−vPromote m = do
299− err <- lift $ runValidationTEither m
300− either vError return err
stack.yaml+2−2
@@ -15,7 +15,7 @@
15# resolver:
15# resolver:
16# name: custom-snapshot
16# name: custom-snapshot
17# location: "./custom-snapshot.yaml"
17# location: "./custom-snapshot.yaml"
18−resolver: lts-22.4
18+resolver: lts-8.14
19
19
20# User packages to be built.
20# User packages to be built.
21# Various formats can be used as shown in the example below.
21# Various formats can be used as shown in the example below.
@@ -63,4 +63,4 @@ extra-package-dbs: []
63# extra-lib-dirs: [/path/to/dir]
63# extra-lib-dirs: [/path/to/dir]
64#
64#
65# Allow a newer minor version of GHC than the snapshot specifies
65# Allow a newer minor version of GHC than the snapshot specifies
66−# compiler-check: newer-minor
66+# compiler-check: newer-minor
test/Doc.hsdeleted−6
@@ -1,6 +0,0 @@
1−module Main (main) where
2−
3−import Test.DocTest
4−
5−main :: IO ()
6−main = doctest [ "-XOverloadedStrings", "-isrc", "src" ]
validationt.cabal+9−47
@@ -2,12 +2,10 @@
2-- documentation, see http://haskell.org/cabal/users-guide/
2-- documentation, see http://haskell.org/cabal/users-guide/
3
3
4name: validationt
4name: validationt
5−version: 0.3.0
5+version: 0.1.0.1
6−synopsis: Straightforward validation monad
6+synopsis: Straightforward validation monad. Convenient solution for validating web forms and APIs.
7−description:
7+-- description:
8− A simple data validation library. The main idea is to provide an easy way to validate web form data by aggregating errors for each field.
9− .
10−homepage: https://github.com/typeable/validationt
8+homepage: typeable.io
11license: BSD3
9license: BSD3
12license-file: LICENSE
10license-file: LICENSE
13author: Typeable.io contributors
11author: Typeable.io contributors
@@ -16,51 +14,15 @@ maintainer: makeit@typeable.io
16category: Control
14category: Control
17build-type: Simple
15build-type: Simple
18extra-source-files: ChangeLog.md
16extra-source-files: ChangeLog.md
19− , README.md
20cabal-version: >=1.10
17cabal-version: >=1.10
21−tested-with: GHC == 8.4.4
22− , GHC == 8.6.5
23− , GHC == 8.8.4
24− , GHC == 8.10.2
25−
26−source-repository head
27− type: git
28− location: git@github.com:typeable/validationt.git
29
18
30library
19library
31 exposed-modules: Control.Monad.Validation
20 exposed-modules: Control.Monad.Validation
21+ -- other-modules:
22+ -- other-extensions:
32− build-depends: base >=4.10 && < 5
23+ build-depends: base >=4.8 && < 5
33− , aeson >=1.0
24+ , aeson >= 1.0
34− , containers
35− , exceptions >=0.9
36− , lens
37− , monad-control
38− , mtl <2.3 || >2.3
39− , QuickCheck >=2.8.2
40− , text
41 , transformers
25 , transformers
42− , transformers-base
26+ , lens
43− , vector
44 hs-source-dirs: src
27 hs-source-dirs: src
45 default-language: Haskell2010
28 default-language: Haskell2010
46− ghc-options: -fwarn-unused-binds
47− -Wall
48− -Wincomplete-uni-patterns
49− -Wincomplete-record-updates
50− -Wpartial-fields
51− -Werror=missing-home-modules
52− -Wmissing-home-modules
53− -Widentities
54− -Wredundant-constraints
55− -Wmissing-export-lists
56−
57−test-suite doctest
58− default-language: Haskell2010
59− type: exitcode-stdio-1.0
60− hs-source-dirs: test
61− ghc-options: -Wall
62− main-is: Doc.hs
63− build-depends:
64− base >= 4.10.0.0
65− , doctest >= 0.11.4
66− , validationt