9a795f5 · rowtype-yoga/purescript-arraybuffer-builder

git.iko.soy/rowtype-yoga/purescript-arraybuffer-builder

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Add cons, length, subBuilder

9a795f5James Brock6 years ago

CHANGELOG.mdnew file+7

compare with master

unifiedsplit

@@ -0,0 +1,7 @@

1+## v1.1.0 2020-09-10

3+Add and export

5+* `cons :: ArrayBuffer -> Builder -> Builder`

6+* `subBuilder :: forall m. (MonadEffect m) => PutM m Unit -> PutM m Builder`

7+* `length :: Builder -> Int`

DEVELOPMENT.md+2−3

@@ -34,10 +34,9 @@ The test dependencies are specified seperately in `test.dhall`.

35```

36[nix-shell:]$ spago bump-version --no-dry-run major

37−[nix-shell:]$ npm install pulp

37+[nix-shell:]$ pulp publish

38−[nix-shell:]$ node node_modules/pulp/index.js publish

39```

38```

41## Bower

40## Bower

43−The `bower.json` is generated by running `spago bump-version`, do not edit it.

42+The `bower.json` is generated by running `spago bump-version`, do not edit it.

shell.nix+3−7

@@ -4,8 +4,8 @@ let

4 (pkgs.fetchFromGitHub {

5 owner = "justinwoo";

6 repo = "easy-purescript-nix";

7− rev = "0ba91d9aa9f7421f6bfe4895677159a8a999bf20";

7+ rev = "1ec689df0adf8e8ada7fcfcb513876307ea34226";

8− sha256 = "1baq7mmd3vjas87f0gzlq83n2l1h3dlqajjqr7fgaazpa9xgzs7q";

8+ sha256 = "12hk2zbjkrq2i5fs6xb3x254lnhm9fzkcxph0a7ngxyzfykvf4hi";

9 }) {

10 inherit pkgs;

11 };

@@ -14,13 +14,9 @@ pkgs.mkShell {

14 buildInputs = [

15 easy-ps.purs-0_13_8

16 easy-ps.spago

17+ easy-ps.pulp

17 pkgs.nodejs-13_x

18 pkgs.nodejs-13_x

18 pkgs.nodePackages.bower

19 pkgs.nodePackages.bower

19− # pkgs.nodePackages.pulp

20− #

21− # The pulp nix derivation doesn't work, so to run pulp:

22− # $ npm install pulp

23− # $ node node_modules/pulp/index.js

24 ];

20 ];

25 LC_ALL = "C.UTF-8"; # https://github.com/purescript/spago/issues/507

21 LC_ALL = "C.UTF-8"; # https://github.com/purescript/spago/issues/507

26}

22}

src/Data/ArrayBuffer/Builder.purs+41−5

@@ -14,6 +14,7 @@ module Data.ArrayBuffer.Builder

14, Put

15, execPutM

16, execPut

17+, subBuilder

17, putArrayBuffer

18, putArrayBuffer

18, putUint8

19, putUint8

19, putInt8

20, putInt8

@@ -32,7 +33,9 @@ module Data.ArrayBuffer.Builder

32, Builder

33, Builder

33, (<>>)

34, (<>>)

34, execBuilder

35, execBuilder

36+, length

35, singleton

37, singleton

38+, cons

36, snoc

39, snoc

37, encodeUint8

40, encodeUint8

38, encodeInt8

41, encodeInt8

@@ -53,7 +56,7 @@ where

54import Prelude

57import Prelude

56−import Control.Monad.Writer.Trans (WriterT, execWriterT, tell)

59+import Control.Monad.Writer.Trans (WriterT, execWriterT, tell, lift)

57import Data.ArrayBuffer.ArrayBuffer as AB

60import Data.ArrayBuffer.ArrayBuffer as AB

58import Data.ArrayBuffer.DataView as DV

61import Data.ArrayBuffer.DataView as DV

59import Data.ArrayBuffer.Typed as AT

62import Data.ArrayBuffer.Typed as AT

@@ -67,10 +70,12 @@ import Effect.Class (class MonadEffect, liftEffect)

67-- | The `PutM` monad is a `WriterT Builder` transformer monad which

70-- | The `PutM` monad is a `WriterT Builder` transformer monad which

68-- | gives us do-notation for the `Builder` monoid. The base monad must be

71-- | gives us do-notation for the `Builder` monoid. The base monad must be

69-- | a `MonadEffect`.

72-- | a `MonadEffect`.

73+-- |

74+-- | To append `Builder`s in this monad call `tell`, or any of the `put*`

75+-- | functions in this module.

70type PutM = WriterT Builder

76type PutM = WriterT Builder

72−-- | The `Put` monad is a `WriterT Builder Effect` monad which

78+-- | The `PutM` type reified to `Effect`, in other words `WriterT Builder Effect`.

73−-- | gives us do-notation for the `Builder` monoid.

74type Put = PutM Effect

79type Put = PutM Effect

76-- | Monoidal builder for `ArrayBuffer`s.

81-- | Monoidal builder for `ArrayBuffer`s.

@@ -143,10 +148,18 @@ foldM f a0 = foldl (\ma b -> ma >>= flip f b) (pure a0)

143singleton :: ArrayBuffer -> Builder

148singleton :: ArrayBuffer -> Builder

144singleton buf = Node Null buf Null

149singleton buf = Node Null buf Null

145

150

151+-- | Prepend an `ArrayBuffer` to the beginning of the `Builder`. *O(1)*

152+cons :: ArrayBuffer -> Builder -> Builder

153+cons x bs = Node Null x bs

154+

146−-- | Add an `ArrayBuffer` to the end of the `Builder`. *O(1)*

155+-- | Append an `ArrayBuffer` to the end of the `Builder`. *O(1)*

147snoc :: Builder -> ArrayBuffer -> Builder

156snoc :: Builder -> ArrayBuffer -> Builder

148snoc bs x = Node bs x Null

157snoc bs x = Node bs x Null

149

158

159+-- | Calculate the total byte length of the `Builder`. *O(n)*

160+length :: Builder -> Int

161+length bldr = foldl (\b a -> b + AB.byteLength a) 0 bldr

162+

150-- | Build a single `ArrayBuffer` from a `Builder`. *O(n)*

163-- | Build a single `ArrayBuffer` from a `Builder`. *O(n)*

151execBuilder :: forall m. (MonadEffect m) => Builder -> m ArrayBuffer

164execBuilder :: forall m. (MonadEffect m) => Builder -> m ArrayBuffer

152execBuilder bldr = do

165execBuilder bldr = do

@@ -173,6 +186,28 @@ execPutM = execBuilder <=< execWriterT

173execPut :: Put Unit -> Effect ArrayBuffer

186execPut :: Put Unit -> Effect ArrayBuffer

174execPut = execPutM

187execPut = execPutM

175

188

189+-- | Build up a sub-`Builder` without `tell`ing it to the `Writer` yet.

190+-- |

191+-- | One case where we might want to call a `subBuilder` is when

192+-- | serializing length-prefixed messages in some protocol. In that case,

193+-- | we must serialize the message first, calculate the message length,

194+-- | append the message length, and then append the message.

195+-- |

196+-- | In a `PutM` monad do-block, we can

197+-- |

198+-- |

199+-- | ```

200+-- | do

201+-- | messageBuilder <- subBuilder $ do

202+-- | putField1

203+-- | putField2

204+-- |

205+-- | putInt32 $ length messageBuilder

206+-- | tell messageBuilder

207+-- | ```

208+subBuilder :: forall m. (MonadEffect m) => PutM m Unit -> PutM m Builder

209+subBuilder = lift <<< execWriterT

210+

176-- | Append an `ArrayBuffer` to the builder.

211-- | Append an `ArrayBuffer` to the builder.

177putArrayBuffer :: forall m. (MonadEffect m) => ArrayBuffer -> PutM m Unit

212putArrayBuffer :: forall m. (MonadEffect m) => ArrayBuffer -> PutM m Unit

178putArrayBuffer = tell <<< singleton

213putArrayBuffer = tell <<< singleton

@@ -404,4 +439,5 @@ putFloat64le = putArrayBuffer <=< encodeFloat64le

404-- so that if we want to change the Builder implementation later then we can.

439-- so that if we want to change the Builder implementation later then we can.

405--

440--

406-- Another way this could go:

441-- Another way this could go:

407−-- https://kodimensional.dev/posts/2019-03-25-comonadic-builders

442+-- https://kodimensional.dev/posts/2019-03-25-comonadic-builders

443+

test/Main.purs+19−1

@@ -7,6 +7,7 @@ import Data.UInt as UInt

7import Effect (Effect)

8import Test.Assert (assertEqual')

9import Data.ArrayBuffer.Builder

10+import Control.Monad.Writer.Trans (tell)

11asBytes :: ArrayBuffer -> Effect (Array Int)

12asBytes :: ArrayBuffer -> Effect (Array Int)

12asBytes x = do

13asBytes x = do

@@ -79,4 +80,21 @@ main = do

79 b7 <- encodeInt8 7

80 b7 <- encodeInt8 7

80 b8 <- encodeInt8 8

81 b8 <- encodeInt8 8

81 pure $ ((singleton b1 <> singleton b2) <> (singleton b3 <> singleton b4))

82 pure $ ((singleton b1 <> singleton b2) <> (singleton b3 <> singleton b4))

82− <> ((singleton b5 <> singleton b6) <> (singleton b7 <> singleton b8))

83+ <> ((singleton b5 <> singleton b6) <> (singleton b7 <> singleton b8))

84+

85+ buildTest "Test 8" [1,2,3,4] $ do

86+ b1 <- encodeInt8 1

87+ b2 <- encodeInt8 2

88+ b3 <- encodeInt8 3

89+ b4 <- encodeInt8 4

90+ pure $ (cons b1 (singleton b2)) <> (cons b3 (singleton b4))

91+

92+ putTest "Test 9" [1,2,2,3,4] $ do

93+ x <- subBuilder $ do

94+ putInt8 3

95+ putInt8 4

96+ putInt8 1

97+ putInt8 2

98+ putInt8 $ length x

99+ tell x

100+