prairie 0.0.3.0 → 0.0.4.0

raw patch · 8 files changed

+178/−1 lines, 8 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• ChangeLog.md +8/−0
• prairie.cabal +5/−1
• src/Prairie.hs +6/−0
• src/Prairie/AsRecord.hs +51/−0
• src/Prairie/Monoid.hs +10/−0
• src/Prairie/Semigroup.hs +17/−0
• src/Prairie/Zip.hs +34/−0
• test/Spec.hs +47/−0

@@ -1,5 +1,13 @@ # Changelog for prairie +## 0.0.4.0++- [#13](https://github.com/parsonsmatt/prairie/pull/13)+    - Introduce `Prairie.Semigroup`, allowing you to combine two records by semigroup-appending their fields together.+    - Introduce `Prairie.Zip`, allowing you to combine two records by specifying how to combine their fields. This fuels `Prairie.Semigroup`.+    - Introduce `Prairie.Monoid`, allowing you to make an `emptyRecord` with `mempty` at each field.+    - Introduce `Prairie.AsRecord`, allowing you to derive instances for records based on their `Record` and `FieldDict` instances.+ ## 0.0.3.0  - [#8](https://github.com/parsonsmatt/prairie/pull/8)

@@ -1,7 +1,7 @@ cabal-version: 1.12  name:           prairie-version:        0.0.3.0+version:        0.0.4.0 description:    Please see the README on GitHub at <https://github.com/parsonsmatt/prairie#readme> homepage:       https://github.com/parsonsmatt/prairie#readme bug-reports:    https://github.com/parsonsmatt/prairie/issues@@ -24,12 +24,16 @@ library   exposed-modules:       Prairie+      Prairie.AsRecord       Prairie.Class       Prairie.Update       Prairie.Diff       Prairie.Fold+      Prairie.Zip       Prairie.Traverse       Prairie.TH+      Prairie.Semigroup+      Prairie.Monoid    build-depends:       base              >= 4.13 && < 5

@@ -7,7 +7,10 @@     , module Prairie.Diff     , module Prairie.Fold     , module Prairie.Traverse+    , module Prairie.Zip     , module Prairie.TH+    , module Prairie.Semigroup+    , module Prairie.Monoid     ) where  import Prairie.Class@@ -16,3 +19,6 @@ import Prairie.TH import Prairie.Traverse import Prairie.Update+import Prairie.Zip+import Prairie.Semigroup+import Prairie.Monoid

@@ -0,0 +1,51 @@+-- | This module contains a newtype 'AsRecord' which is used to provide+-- a variety of default instances for types based on their 'Record'+-- instance.+module Prairie.AsRecord where++import Prairie.Class+import Prairie.Monoid+import Prairie.Semigroup++-- | This @newtype@ is intended for use with @DerivingVia@.+--+-- For an example use, let's consider this @User@ datatype:+--+-- > data Foo = Foo+-- >     { ints :: [Int]+-- >     , char :: First Char+-- >     }+-- >+-- > mkRecord ''Foo+--+-- Let's say we want to define an instance of 'Semigroup' for this type, so+-- that we can combine two of them. Ordinarily, we'd need to write+-- a boilerplate-y instance:+--+-- > instance Semigroup Foo where+-- >     f0 <> f1 = Foo+-- >         { ints = f0.ints <> f1.ints+-- >         , char = f0.char <> f1.char+-- >         }+--+-- With @DerivingVia@, we can use 'AsRecord' to provide it easily:+--+-- @+-- deriving via AsRecord Foo instance Semigroup Foo+-- @+--+-- @since 0.0.4.0+newtype AsRecord rec = AsRecord { unAsRecord :: rec }++-- |+--+-- @since 0.0.4.0+instance (Record rec, FieldDict Semigroup rec) => Semigroup (AsRecord rec) where+    AsRecord r0 <> AsRecord r1 =+        AsRecord (appendRecord r0 r1)++-- |+--+-- @since 0.0.4.0+instance (Record rec, FieldDict Semigroup rec, FieldDict Monoid rec) => Monoid (AsRecord rec) where+    mempty = AsRecord emptyRecord

@@ -0,0 +1,10 @@+module Prairie.Monoid where++import Prairie.Class++-- | Create a 'mempty' 'Record' assuming that all of the fields of the+-- record have a 'Monoid' instance.+--+-- @since 0.0.4.0+emptyRecord :: (Record rec, FieldDict Monoid rec) => rec+emptyRecord = tabulateRecord (\field -> withFieldDict @Monoid field mempty)

@@ -0,0 +1,17 @@+-- | This module provides the ability to append two records using '(<>)',+-- provided that all of their fields have an instance of 'Semigroup'.+module Prairie.Semigroup where++import Prairie.Class+import Prairie.Zip++-- | Zip two records together using a 'Semigroup' append.+--+-- @since 0.0.4.0+appendRecord+    :: forall rec. (Record rec, FieldDict Semigroup rec)+    => rec+    -> rec+    -> rec+appendRecord =+    zipWithRecord (\a b field -> withFieldDict @Semigroup field (a <> b))

@@ -0,0 +1,34 @@+module Prairie.Zip where++import Prairie.Class+import Prairie.Fold++-- | Take two records and zip them together with the provided function.+--+-- The field is given for the final parameter in the function, allowing you to use @LambdaCase@.+--+-- @+-- zipWithRecord+--     (\a b ->+--         \case+--             UserName ->+--                 a <> b+--             UserAge ->+--                 a + b+--     )+-- @+--+-- @since 0.0.4.0+zipWithRecord+    :: forall rec. (Record rec)+    => (forall ty. ty -> ty -> Field rec ty -> ty)+    -> rec+    -> rec+    -> rec+zipWithRecord k r0 r1 =+    foldRecord f r0 r0+  where+      f :: ty -> rec -> Field rec ty -> rec+      f v0 rec field =+          let v1 = getRecordField field r1+           in setRecordField field (k v0 v1 field) rec

@@ -1,12 +1,18 @@+{-# LANGUAGE ApplicativeDo #-}+{-# LANGUAGE BlockArguments #-} {-# LANGUAGE ConstraintKinds #-} {-# LANGUAGE DataKinds #-}+{-# LANGUAGE DerivingVia #-}+{-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE GADTs #-}+{-# LANGUAGE InstanceSigs #-} {-# LANGUAGE LambdaCase #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE OverloadedStrings #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE RankNTypes #-}+{-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE TemplateHaskell #-} {-# LANGUAGE TypeApplications #-}@@ -24,6 +30,8 @@ import Data.Aeson import Data.Kind (Type) import Data.Monoid+import GHC.Records+import Prairie.AsRecord import Test.Hspec  data User = User { name :: String, age :: Int }@@ -36,6 +44,17 @@  exampleUser = User "Alice" 30 +data Foo = Foo+    { ints :: [Int]+    , char :: First Char+    }+    deriving (Show, Eq)++mkRecord ''Foo++deriving via AsRecord Foo instance Semigroup Foo+deriving via AsRecord Foo instance Monoid Foo+ data T a = T { x :: a, y :: Int }  instance Record (T a) where@@ -197,3 +216,31 @@                     User { name = "", age = 30 }                     `shouldBe`                         Nothing++        describe "Semigroup" do+            it "can combine two records" do+                let f0 = Foo [1] (First Nothing)+                    f1 = Foo [2,3] (First (Just 'a'))+                f0 <> f1+                    `shouldBe`+                        Foo [1,2,3] (First (Just 'a'))++        describe "Monoid" do+            it "can produce an empty record" do+                let obvious =+                        Foo mempty mempty+                mempty `shouldBe` obvious++        describe "Zip" do+            it "can combine two records" do+                let u0 = User "Matt" 35+                    u1 = User "ttaM" 53+                zipWithRecord (\a b -> \case+                    UserName ->+                        a <> b+                    UserAge ->+                        a + b+                    ) u0 u1+                    `shouldBe`+                        User "MattttaM" (35 + 53)+