Merge pull request #550 from phadej/stuhv

Add parserThrowError and parserCatchError

Author: bergmark

.gitignore

@@ -1,5 +1,6 @@
 dist
 dist-newstyle
+.ghc.environment.*
 .cabal-sandbox/
 cabal.sandbox.config
 .stack-work/

Data/Aeson/Types.hs

@@ -36,6 +36,8 @@ module Data.Aeson.Types
     , ToJSON(..)
     , KeyValue(..)
     , modifyFailure
+    , parserThrowError
+    , parserCatchError
 
     -- ** Keys for maps
     , ToJSONKey(..)

Data/Aeson/Types/Internal.hs

@@ -44,6 +44,8 @@ module Data.Aeson.Types.Internal
     , parseEither
     , parseMaybe
     , modifyFailure
+    , parserThrowError
+    , parserCatchError
     , formatError
     , (<?>)
     -- * Constructors and accessors
@@ -507,7 +509,22 @@ p <?> pathElem = Parser $ \path kf ks -> runParser p (pathElem:path) kf ks
 --
 -- Since 0.6.2.0
 modifyFailure :: (String -> String) -> Parser a -> Parser a
-modifyFailure f (Parser p) = Parser $ \path kf ks -> p path (\p' m -> kf p' (f m)) ks
+modifyFailure f (Parser p) = Parser $ \path kf ks ->
+    p path (\p' m -> kf p' (f m)) ks
+
+-- | Throw a parser error with an additional path.
+--
+-- @since 1.2.1.0
+parserThrowError :: JSONPath -> String -> Parser a
+parserThrowError path' msg = Parser $ \path kf _ks ->
+    kf (reverse path ++ path') msg
+
+-- | A handler function to handle previous errors and return to normal execution.
+--
+-- @since 1.2.1.0
+parserCatchError :: Parser a -> (JSONPath -> String -> Parser a) -> Parser a
+parserCatchError (Parser p) handler = Parser $ \path kf ks ->
+    p path (\e msg -> runParser (handler e msg) path kf ks) ks
 
 --------------------------------------------------------------------------------
 -- Generic and TH encoding configuration

aeson.cabal

@@ -225,7 +225,7 @@ test-suite tests
     unordered-containers,
     uuid-types,
     vector,
-    quickcheck-instances >=0.3.12
+    quickcheck-instances >=0.3.14
 
   if flag(bytestring-builder)
     build-depends: bytestring >= 0.9 && < 0.10.4,

changelog.md

@@ -1,5 +1,9 @@
 For the latest version of this document, please see [https://github.com/bos/aeson/blob/master/changelog.md](https://github.com/bos/aeson/blob/master/changelog.md).
 
+## 1.2.1.0
+
+* Add `parserThrowError` and `parserCatchError` combinators.
+
 ## 1.2.0.0
 
 * `tagSingleConstructors`, an option to encode single-constructor types as tagged sums was added to `Options`. It is disabled by default for backward compatibility.

stack-bench.yaml

@@ -2,3 +2,5 @@ resolver: lts-8.5
 packages:
 - '.'
 - benchmarks
+extra-deps:
+- quickcheck-instances-0.3.14

stack-lts6.yaml

@@ -3,8 +3,13 @@ packages:
 - '.'
 - attoparsec-iso8601
 extra-deps:
-- semigroups-0.18.2
 - integer-logarithms-1
+- QuickCheck-2.9.2
+- quickcheck-instances-0.3.14
+- semigroups-0.18.2
+- tagged-0.8.5
+- transformers-compat-0.5.1.4
+flags:
 flags:
   aeson:
     fast: true

stack-lts7.yaml

@@ -4,6 +4,7 @@ packages:
 - attoparsec-iso8601
 extra-deps:
 - integer-logarithms-1
+- quickcheck-instances-0.3.14
 flags:
   aeson:
     fast: true

stack-lts8.yaml

@@ -2,6 +2,8 @@ resolver: lts-8.1
 packages:
 - '.'
 - attoparsec-iso8601
+extra-deps:
+- quickcheck-instances-0.3.14
 flags:
   aeson:
     fast: true

stack-nightly.yaml

@@ -2,6 +2,8 @@ resolver: nightly-2017-03-25
 packages:
 - '.'
 - attoparsec-iso8601
+extra-deps:
+- quickcheck-instances-0.3.14
 flags:
   aeson:
     fast: true