diff --git a/CHANGELOG.md b/CHANGELOG.md new file mode 100644 --- /dev/null +++ b/CHANGELOG.md @@ -0,0 +1,9 @@ +# Changelog for json-to-haskell + +## 0.1.1.2 +- Fix including changelog in package + +## 0.1.1.1 +- Only look at first element of lists when determining type + +## Unreleased changes diff --git a/CHANGElOG.md b/CHANGElOG.md deleted file mode 100644 --- a/CHANGElOG.md +++ /dev/null @@ -1,6 +0,0 @@ -# Changelog for json-to-haskell - -## 0.1.1.1 -- Only look at first element of lists when determining type - -## Unreleased changes diff --git a/README.md b/README.md --- a/README.md +++ b/README.md @@ -1,8 +1,183 @@ # json-to-haskell + + +* [Web interface](#web-interface) +* [What is it?](#what-is-it) +* [Installation](#installation) +* [Usage](#usage) +* [Help Wanted](#help-wanted) + + + +## Web interface + +[Click here for the web interface](http://json-to-haskell.chrispenner.ca/) +[Web interface source code (Miso)](https://github.com/ChrisPenner/json-to-haskell-web) + +## What is it? + In goes JSON, out comes Haskell! -```json -{ +A handy tool for quickly spec'ing out types for a given JSON type. + +**Note: This tool isn't perfect, but it should get you _most_ of the way there.** + +```sh +$ cat > company.json +{ "company": + { "employees": + [ {"name": "Jon", "age": 32} + , {"name": "Alice", "age": 27} + ] + , "star_rating": 4.7 + } } ``` + +```haskell +$ cat company.json | json-to-haskell +{-# LANGUAGE DuplicateRecordFields #-} +{-# LANGUAGE RecordWildCards #-} +{-# LANGUAGE OverloadedStrings #-} +module Model where + +import Data.Aeson (ToJSON(..), FromJSON(..), Value(..), (.:), (.=), object) +import Data.Aeson.Types (prependFailure, typeMismatch) +import Data.Text (Text) + +data Company = Company + { companyStarRating :: Double + , companyEmployees :: [Employees] + } deriving (Show, Eq, Ord) + +data Employees = Employees + { employeesAge :: Int + , employeesName :: Text + } deriving (Show, Eq, Ord) + +data Model = Model + { modelCompany :: Company + } deriving (Show, Eq, Ord) + +instance ToJSON Company where + toJSON Company{..} = object + [ "star_rating" .= companyStarRating + , "employees" .= companyEmployees + ] + +instance ToJSON Employees where + toJSON Employees{..} = object + [ "age" .= employeesAge + , "name" .= employeesName + ] + +instance ToJSON Model where + toJSON Model{..} = object + [ "company" .= modelCompany + ] + +instance FromJSON Company where + parseJSON (Object v) = do + companyStarRating <- v .: "star_rating" + companyEmployees <- v .: "employees" + pure $ Company{..} + parseJSON invalid = do + prependFailure "parsing Company failed, " + (typeMismatch "Object" invalid) + +instance FromJSON Employees where + parseJSON (Object v) = do + employeesAge <- v .: "age" + employeesName <- v .: "name" + pure $ Employees{..} + parseJSON invalid = do + prependFailure "parsing Employees failed, " + (typeMismatch "Object" invalid) + +instance FromJSON Model where + parseJSON (Object v) = do + modelCompany <- v .: "company" + pure $ Model{..} + parseJSON invalid = do + prependFailure "parsing Model failed, " + (typeMismatch "Object" invalid) +``` + +## Installation + +Take your pick: + +```sh +cabal install haskell-to-json +# OR +stack install haskell-to-json +``` + +## Usage + +There's a web interface [here](http://json-to-haskell.chrispenner.ca/) if you prefer. + + +Otherwise, install the cli and ask for help; the cli will have the most up to date help message: + +```sh +$ json-to-haskell --help +Usage: json-to-haskell [-t|--tab-stop ARG] [-n|--numbers ARG] [-s|--strings ARG] + [-m|--maps ARG] [-l|--lists ARG] [--no-module-header] + [--no-instances] [--no-prefix-record-fields] [--strict] + +Available options: + -t,--tab-stop ARG Number of spaces to indent each level. + -n,--numbers ARG Type to use for numbers. + + 'smart-floats': + Use floats for numbers with decimals, Int for whole numbers. + 'smart-doubles': + Use floats for numbers with decimals, Int for whole numbers. + 'floats': + Use floats for all numbers. + 'doubles': + Use doubles for all numbers. + 'scientific': + Use scientific for all numbers. + + -s,--strings ARG Type to use for strings. + + 'string': + Use String for strings. + 'text': + Use Text for strings. + 'bytestring': + Use ByteString for strings. + + -m,--maps ARG Type to use for maps. + + 'map': + Use Data.Map for maps. + 'hashmap': + Use Data.HashMap for maps. + + -l,--lists ARG Type to use for lists. + + 'list': + Use [] for lists. + 'vector': + Use Data.Vector for lists. + + --no-module-header Omit the module header containing language extensions, module definition and imports. + --no-instances Omit the ToJSON and FromJSON instances. + --no-prefix-record-fields + Omit record field prefixes. + --strict Use strict record fields. + -h,--help Show this help text +``` + +## Help Wanted + +Want to help out? + +I'd love to have a Purescript version of the app! It should be pretty easy to port, you'd just need to adapt the "printer" for the parsed data type. +Check out [Printer.hs](./src/JsonToHaskell/Internal/Printer.hs) . + +It'd also be really nice to port the whole project to Purescript, the current miso build is difficult to set up locally. diff --git a/json-to-haskell.cabal b/json-to-haskell.cabal --- a/json-to-haskell.cabal +++ b/json-to-haskell.cabal @@ -4,10 +4,10 @@ -- -- see: https://github.com/sol/hpack -- --- hash: 2c356673661763f7b6e9541e054c697801872e029c40f11d3ca0f795c52037cf +-- hash: cc4c6327c9fb7753bcb567426edabc8f0136cde2af157aee72e577bdd2e492d7 name: json-to-haskell -version: 0.1.1.1 +version: 0.1.1.2 description: Please see the README on GitHub at homepage: https://github.com/ChrisPenner/json-to-haskell#readme bug-reports: https://github.com/ChrisPenner/json-to-haskell/issues @@ -19,7 +19,7 @@ build-type: Simple extra-source-files: README.md - CHANGElOG.md + CHANGELOG.md source-repository head type: git