JSONToTable

JSON to Haskell Converter

Convert JSON data to Haskell data types with Aeson support

JSON Input

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Haskell Output

Haskell code will appear here

Paste JSON in the input area to get started

How to Convert JSON to Haskell Data Types - Step by Step Guide

Step 1

Input Your JSON Data

Start by adding your JSON data that needs to be converted to Haskell data types. The tool analyzes the structure to generate appropriate data types with Aeson support.

Example: Try This JSON Data

Copy and paste this JSON example to see how it works: 🎆

{
  "userId": 12345,
  "username": "haskeller",
  "email": "dev@haskell.org",
  "isActive": true,
  "preferences": [
    "pure_functions",
    "lazy_evaluation",
    "type_safety"
  ],
  "profile": {
    "firstName": "Haskell",
    "lastName": "Curry",
    "age": 35,
    "country": "UK"
  }
}
Step 2

Configure Haskell Options

Customize how your JSON is converted to Haskell data types! ⚙️ Choose Aeson support and type-safe functional programming patterns.

•
Data types: Generate algebraic data types with type safety and pattern matching
•
Aeson support: Compatible with Aeson for JSON parsing and encoding
•
Nested types: Handle complex JSON hierarchies with nested Haskell data types
•
Type mapping: Automatic Haskell type mapping from JSON data types
Step 3

Get Generated Haskell Code

Watch the transformation! ✨ Your JSON structure becomes clean, type-safe Haskell data types ready for functional programming.

Haskell Code Output

Your JSON becomes these Haskell data types:

{-# LANGUAGE DeriveGeneric #-}

import Data.Aeson
import GHC.Generics

data Profile = Profile
  {  firstName :: String
  , lastName  :: String
  , age       :: Int
  , country   :: String
  }  deriving (Show, Generic)

instance FromJSON Profile
instance ToJSON Profile

data Root = Root
  {  userId      :: Int
  , username    :: String
  , email       :: String
  , isActive    :: Bool
  , preferences :: [String]
  , profile     :: Profile
  }  deriving (Show, Generic)

instance FromJSON Root
instance ToJSON Root
Step 4

Copy or Download Haskell Code

Perfect! Now you can use your Haskell data types in your functional applications for JSON processing. 🚀

•
Copy to clipboard for immediate use in your Haskell projects
•
Download .hs files for integration into your Cabal or Stack project
•
Use with frameworks like Servant and Yesod
•
Haskell applications and functional programming

What is JSON to Haskell Conversion? 🎆

JSON to Haskell conversion transforms JSON data structures into algebraic data types with Aeson support for type-safe functional programming. This process analyzes JSON structure and generates Haskell data types that can parse and encode JSON data, making it easy to work with APIs in Haskell applications.

The generated Haskell data types include proper field types, Generic deriving for automatic Aeson instances, and FromJSON/ToJSON instances, enabling pure functional JSON handling with compile-time type safety and lazy evaluation.

Frequently Asked Questions

What Haskell features are generated for JSON handling?

The tool generates algebraic data types with Generic deriving, automatic FromJSON and ToJSON instances, proper field types, and pattern matching support for type-safe JSON parsing and encoding with Aeson.

Can I use the generated types with Aeson?

Absolutely! The generated Haskell data types work perfectly with Aeson for JSON serialization and deserialization. They include automatic FromJSON and ToJSON instances using Generic deriving for seamless JSON processing.

How are nested JSON objects handled in Haskell?

Nested JSON objects become separate Haskell data types with proper relationships. The tool creates a type hierarchy that mirrors your JSON structure, with parent types containing fields of child data types.

What Haskell data types are used for JSON values?

JSON strings become Haskell String, numbers become Int or Double, booleans become Bool, arrays become [Type], and objects become custom data types. The tool intelligently maps JSON types to appropriate Haskell types.

Do the generated types support pattern matching?

Yes! The algebraic data types support full Haskell pattern matching, allowing you to destructure data, match on constructors, and use guards for robust data processing in pure functional style.

Is the JSON to Haskell converter free to use?

Yes, completely free with no limitations on JSON complexity, data type generation, or usage frequency. No registration required, and you can generate unlimited Haskell data types from JSON data at no cost.