Aeson combinators for dead simple JSON decoding

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LTS Haskell 21.24:
Stackage Nightly 2023-12-10:
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BSD-3-Clause licensed and maintained by Marek Fajkus
This version can be pinned in stack with:aeson-combinators-,2260

Module documentation for

Aeson Combinators

Build Status

This library defines low overhead value space Decoder on top of Aeson’s Parser for combinator style decoding.

This library is compatible with GHC 7.6 and later as well as recent versions of GHCJS.

Encoding to JSON is currently not supported but might be added in the future version.

I wrote a blob post describing what this library attempts to solve.


This library introduces as low overhead over Aeson API as possible. Decoder a type is a function Value -> Parser a same as fromJSON function of FromJSON class. This means there should be near zero overhead. Aeson types and functions are reused where possible.


  • [x] Documentation
  • [x] Support for more GHC versions
  • [x] Default decoders for Containers
  • [ ] Encoding API


(c) 2020 Marek Fajkus BSD-3-Clause


Revision history for aeson-combinators – 2020-03-08

  • Add README to extra source files – 2020-03-08

  • GHCJS compatibility – 2020-03-01

  • Fixes and improvements in documentation
  • Add source-repository to cabal file – 2020-02-29

  • First version. Released on an unsuspecting world.