Json to HTML convertor

Build Guide

cabal exec -- ghc --make scanner.hs
./scanner input.json output.html

Result

Origin Json File

{
    "quiz": {
        "sport": {
            "q1": {
                "question": "Which one is correct team name in NBA?",
                "options": [
                    "New York Bulls",
                    "Los Angeles Kings",
                    ...
                ],
                "answer": "Huston Rocket",
                "age": 31,
                "case": true
            }
        },
        ...
    }
}

HTML opened in browser

Tricks

Syntax

About $ and .
Maybe and Just

IO _ when return type is IO _, use <- to assign it to a variable

addOne :: Int -> IO Int
addOne x = do
    return x 

main = do
    value <- addOne 1
    print(value)

unusual show

> show '"'
"'\"'" :: String
> show '\\'
"\\\\" :: String
> show 'x'
"'x'" :: String

if want to convert Char to String

> ['x']
"x" :: [Char]

Regular Expression with PCRE

regex cheat sheet Install

$ cabal install regex-pcre

Error may occur

Wrap.hsc:148:10: fatal error: 'pcre.h' file not found
#include <pcre.h>

solution for mac

brew install pcre
cabal install regex-pcre

cabal

Manage packages in local directroy

cabal sandbox init

to use ghci with packages with local sandboxs

# For GHC < 7.6
$ ghci -no-user-package-conf -package-conf .cabal-sandbox/x86_64-osx-ghc-8.2.2-packages.conf.d

to comile hs file with local sandboxs

cabal exec -- ghc --make myhaskell.hs