Autocorrection

Overview

Our project is to build a web application using Haskell to provide an auto-correct function for misspelled English words and sentences. Users are able to enter an arbitrary word/sentence in the text box at their discretion and our algorithm will examine if it is a valid, and provide reommendations. The whole structure is built on Yesod, which is a lightweight Haskell-based web framework. We also use persistent as our data model and edit distance as our recommendation algorithm.

Team

• Haimeng Wang (pennkey: whm7)
• Shu Chen (pennkey: s388chen)
• Yuxin Kan (pennkey: irenekxx)

Components

1. A Widget's Html, CSS and Javascript are separated in three files with the .hamlet, .lucius and .julius extensions. All the files for templates and widgets are in templates folder.
2. In Yesod framework, routing and handlers make up the controller. Routing is abstracted in config/routes.yesodroutes and all of the route handlers are in src/Hander.
3. We define database entities in the entities file config/models.persistentmodels. We also enable connecting to an additional existing sqlite database by creating a standalone module src/DitionaryDB.hs.
4. We have integration tests, quicktests and unit tests in test/.

Quick Start Guide

1. If you haven't already, install Stack
   • On POSIX systems, this is usually

      curl -sSL https://get.haskellstack.org/ | sh
     

2. Install the yesod command line tool.

   stack install yesod-bin --install-ghc
   

3. Build libraries.

   stack build
   

4. To keep sensitive data out of code, we add extra package dotenv. To run this server, user should add a dotenv (.env) file in the root dictionary with local dictionary db path.

   Dictionary_DB=<local path>/shu_haimeng_xingxing/config/Dictionary.db
   

5. Start a development server with:

   stack exec -- yesod devel
   

Useful commands

Executable named yesod not found on path.

stack build yesod-bin

Add new handler

stack exec -- yesod add-handler

Tests

stack test --flag autograd:library-only --flag autograd:dev

(Because yesod devel passes the library-only and dev flags, matching those flags means you don't need to recompile between tests and development, and it disables optimization to speed up your test compile times).