upd optics-by-example

deemp · Jul 11, 2023 · a55e5ec · a55e5ec
1 parent fd2394b
commit a55e5ec
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diff --git a/haskell/optics-by-example/README.hs b/haskell/optics-by-example/README.hs
@@ -22,6 +22,7 @@ Notes on [Optics by example](https://leanpub.com/optics-by-example).
 
 {- FOURMOLU_DISABLE -}
 
+{-# LANGUAGE ImportQualifiedPost #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE InstanceSigs #-}
@@ -52,7 +53,7 @@ Notes on [Optics by example](https://leanpub.com/optics-by-example).
 
 {- FOURMOLU_ENABLE -}
 
-module Main (main) where
+module README (main) where
 
 import Control.Applicative (Applicative (..))
 import Control.Lens
@@ -3925,17 +3926,6 @@ ex74 = exercises ^.. traversed . at "pushups" . non 0
 -- >>> ex74
 -- [0,10,15]
 
-
-x :: Map.Map Text.Text Int
-x = fromList [("WORLD", 456)]
-
-x1 :: Map.Map Text.Text Int
-x1 = x & at "HELLO" . non 678 .~ 3
-
--- >>> x1
--- fromList [("HELLO",3),("WORLD",456)]
-
-
 {-
 1. Board
 

diff --git a/haskell/optics-by-example/optics-by-example.cabal b/haskell/optics-by-example/optics-by-example.cabal
@@ -19,10 +19,14 @@ source-repository head
   type: git
   location: https://github.com/value/optics-by-example
 
-executable optics-by-example
-  main-is: README.hs
+library
+  exposed-modules:
+      Extra
+      README
   other-modules:
       Paths_optics_by_example
+  hs-source-dirs:
+      src
   default-extensions:
       ImportQualifiedPost
       OverloadedRecordDot

diff --git a/haskell/optics-by-example/package.yaml b/haskell/optics-by-example/package.yaml
@@ -37,24 +37,24 @@ ghc-options:
   - -Wpartial-fields
   - -Wredundant-constraints
 
-executables:
-  optics-by-example:
-    main: README.hs
-    ghc-options:
-      - -threaded
-      - -rtsopts
-      - -with-rtsopts=-N
-    dependencies:
-      - aeson
-      - containers
-      - lens
-      - lens-aeson
-      - mtl
-      - text
-      - template-haskell
-      - bytestring
-      - either
-      - generic-lens
+library:
+  source-dirs: src
+  ghc-options:
+    - -threaded
+    - -rtsopts
+    - -with-rtsopts=-N
+  dependencies:
+    - aeson
+    - containers
+    - lens
+    - lens-aeson
+    - mtl
+    - text
+    - template-haskell
+    - bytestring
+    - either
+    - generic-lens
+    - split
 
 tests:
   docs:

diff --git a/haskell/optics-by-example/src/Extra.hs b/haskell/optics-by-example/src/Extra.hs
@@ -0,0 +1,52 @@
+{-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE ImportQualifiedPost #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeFamilies #-}
+
+module Extra where
+
+import Control.Lens
+import Control.Monad.State (execState, modify)
+import Data.Generics.Labels ()
+import Data.Map (fromList)
+import Data.Map qualified as Map
+import Data.Text qualified as Text
+import Data.Traversable (for)
+
+{-
+## `non`
+-}
+
+ex1 :: Map.Map Text.Text Int
+ex1 = fromList [("WORLD", 456)]
+
+ex2 :: Map.Map Text.Text Int
+ex2 = ex1 & at "HELLO" . non 678 .~ 3
+
+-- >>> x1
+-- fromList [("HELLO",3),("WORLD",456)]
+
+{-
+## update at multiple indices
+-}
+
+ex3 :: [Text.Text] -> Int -> Map.Map Text.Text Int -> Map.Map Text.Text Int
+ex3 ks val = execState (traverse (\k -> modify (at k ?~ val)) ks)
+
+ex4 :: Map.Map Text.Text Int
+ex4 = Map.empty & ex3 ["a", "b", "c"] 4
+
+-- >>> ex4
+-- fromList [("a",4),("b",4),("c",4)]
+
+ex5 :: Map.Map String Integer
+ex5 = Map.empty &~ for ["b", "c", "d"] (\k -> at k ?= 10)
+
+-- >>> ex5
+-- fromList [("b",10),("c",10),("d",10)]