Aeson

Aeson is a name that appears in different contexts. In Greek mythology, Aeson was the king of Iolcus in Thessaly and the father of Jason. In most versions his throne is usurped by Pelias, leading to exile or imprisonment. The tale of Jason’s quest for the Golden Fleece, and Medea’s involvement, is linked to Aeson’s fate and the fate of his house, with various ancient sources offering different details about his life and downfall.

In computing, Aeson is a popular JSON library for the Haskell programming language. It provides a practical interface for encoding and decoding JSON data, centered on the FromJSON and ToJSON type classes that map between JSON values and Haskell types. Core operations include decode and eitherDecode for parsing, and encode for serialization. Aeson supports automatic derivation of JSON instances through GHC Generics and, via Template Haskell (Data.Aeson.TH), through deriveJSON-style helpers. This combination enables concise definitions of data structures that can be easily serialized to or deserialized from JSON, making Aeson a standard choice in many Haskell projects.