Functions for Encoding JSON Values

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Revision history for HsYAML-aeson
 
+## 0.2.0.0
+
+* Changes in accordance with HsYAML-0.2.0.0 (#1)
+    * New convinence function `decode1Strict`
+    * New functions`encode1`, `encode1Strict`, `encodeValue`, `encodeValue'` for encoding JSON Values
+
 ## 0.1.0.0
 
 * First release. Released on an unsuspecting world.

HsYAML-aeson.cabal

@@ -1,6 +1,6 @@
 cabal-version:       2.2
 name:                HsYAML-aeson
-version:             0.1.0.0
+version:             0.2.0.0
 license:             GPL-2.0-or-later
 license-file:        LICENSE.GPLv2
 author:              Herbert Valerio Riedel
@@ -34,8 +34,11 @@ library
     , aeson       ^>= 1.4.0.0
     , base         >= 4.5 && < 4.13
     , bytestring  ^>= 0.9.2.1 || ^>= 0.10.0.2
+    , containers   >=0.4.2 && <0.7
     , mtl         ^>= 2.2.1
+    , scientific  ^>= 0.3.6.2
     , text        ^>= 1.2.3.1
+    , unordered-containers >= 0.2 && < 0.3
     , vector      ^>= 0.12.0.2
 
   hs-source-dirs:      src

cabal.project

@@ -0,0 +1,8 @@
+packages: .
+
+source-repository-package
+    type: git
+    location: https://github.com/hvr/HsYAML.git
+
+package HsYAML-aeson
+  flags: +exe

src/Data/YAML/Aeson.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP             #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE Trustworthy     #-}
 
@@ -19,23 +20,34 @@
 module Data.YAML.Aeson
     ( -- * Parsing YAML using JSON models
       -- ** High-level parsing/decoding via 'FromJSON' instances
-      Data.YAML.Aeson.decode1
+      decode1
     , decode1'
+    , decode1Strict
       -- ** Parsing into JSON AST ('J.Value')
     , decodeValue
     , decodeValue'
     , scalarToValue
+      -- ** Encoding/Dumping 
+    , encode1
+    , encode1Strict
+    , encodeValue
+    , encodeValue'
     ) where
 
 import           Control.Applicative    as Ap
 import           Control.Monad.Identity (runIdentity)
 import           Data.Aeson             as J
 import qualified Data.Aeson.Types       as J
 import qualified Data.ByteString.Lazy   as BS.L
+import qualified Data.ByteString        as BS
 import           Data.Text              (Text)
 import qualified Data.Vector            as V
-import           Data.YAML              as Y
+import           Data.YAML              as Y  hiding (decode1, decode1Strict, encode1, encode1Strict)
 import           Data.YAML.Event        (Pos)
+import qualified Data.YAML.Token        as YT
+import           Data.Scientific
+import qualified Data.Map               as Map
+import qualified Data.HashMap.Strict    as HM
 
 -- | Parse a single YAML document using the 'coreSchemaResolver' and decode to Haskell types using 'FromJSON' instances.
 --
@@ -57,6 +69,12 @@ decode1 bs = case decodeValue bs of
         J.Success v2 -> Right $! v2
         J.Error err  -> Left ("fromJSON: " ++ err)
 
+-- | Like 'decode1' but takes a strict 'BS.ByteString'
+--
+-- @since 0.2.0
+decode1Strict :: FromJSON v => BS.ByteString -> Either String v
+decode1Strict = decode1 . BS.L.fromChunks . (:[])
+
 -- | Variant of 'decode1' allowing for customization. See 'decodeValue'' for documentation of parameters.
 decode1' :: FromJSON v => SchemaResolver -> (J.Value -> Either String Text) -> BS.L.ByteString -> Either String v
 decode1' schema keyconv bs = case decodeValue' schema keyconv bs of
@@ -142,3 +160,58 @@ scalarToValue (Y.SFloat x)   = Just $! J.Number (realToFrac x)
 scalarToValue (Y.SInt i)     = Just $! J.Number (fromInteger i)
 scalarToValue (SStr t)       = Just $! J.String t
 scalarToValue (SUnknown _ _) = Nothing
+
+
+-- | Equivalent to the fuction Data.ByteString.toStrict.
+-- O(n) Convert a lazy ByteString into a strict ByteString.
+{-# INLINE bsToStrict #-}
+bsToStrict :: BS.L.ByteString -> BS.ByteString
+#if MIN_VERSION_bytestring(0,10,0)
+bsToStrict = BS.L.toStrict
+#else
+bsToStrict = BS.concat . BS.L.toChunks
+#endif
+
+-- | @since 0.2.0
+instance ToYAML J.Value where
+  toYAML J.Null = Scalar () SNull
+  toYAML (J.Bool b) = toYAML b
+  toYAML (J.String txt) = toYAML txt
+  toYAML (J.Number sc) = case floatingOrInteger sc :: Either Double Integer of
+    Right d -> toYAML d
+    Left int -> toYAML int
+  toYAML (J.Array a) = toYAML (V.toList a)
+  toYAML (J.Object o) = toYAML (Map.fromList (HM.toList o))
+
+-- | Serialize JSON Value using the YAML 1.2 Core schema to a lazy 'BS.L.ByteString'.
+--
+-- 'encode1' emits exactly one YAML document.
+--
+-- See 'encodeValue' for more information about this functions' YAML
+-- encoder configuration.
+--
+-- @since 0.2.0
+encode1 :: ToJSON v => v -> BS.L.ByteString
+encode1 a = encodeValue [J.toJSON a]
+
+-- | Like 'encode1' but outputs 'BS.ByteString'
+--
+-- @since 0.2.0
+encode1Strict :: ToJSON v => v -> BS.ByteString
+encode1Strict = bsToStrict . encode1
+
+-- | Dump YAML Nodes as a lazy 'BS.L.ByteString'
+--
+-- Each YAML 'Node' is emitted as a individual YAML Document where each Document is terminated by a 'DocumentEnd' indicator.
+--
+-- This is a convenience wrapper over `encodeNode'`
+--
+-- @since 0.2.0
+encodeValue :: [J.Value] -> BS.L.ByteString
+encodeValue = encodeValue' coreSchemaEncoder YT.UTF8
+
+-- | Customizable variant of 'encodeNode'
+--
+-- @since 0.2.0
+encodeValue' :: SchemaEncoder -> YT.Encoding -> [J.Value] -> BS.L.ByteString
+encodeValue' schemaEncoder encoding values = Y.encodeNode' schemaEncoder encoding (map (Doc. toYAML) values)