Pretty.elm

module Debug.Pretty exposing (..)

import String
import Native.Pretty


type alias Model =
    ( Int, List Char )


n : Char
n =
    Native.Pretty.n


t : Char
t =
    Native.Pretty.t


tab : Int -> List Char
tab depth =
    [ n ] ++ List.repeat depth t


type alias Parse =
    { depth : Int
    , isTup : Bool
    , isList : Bool
    , res : List Char
    }


init : Parse
init =
    { depth = 1
    , isTup = False
    , isList = False
    , res = []
    }


newlineOnOpen : Char -> Parse -> Parse
newlineOnOpen char ({ depth, isTup, isList, res } as parse) =
    let
        charAdded =
            { parse | res = res ++ [ char ] }
    in
        case char of
            '{' ->
                { parse
                    | depth = depth + 1
                    , res = res ++ tab (depth + 1) ++ [ char ]
                }

            '}' ->
                { parse
                    | depth = depth - 1
                    , res = res ++ tab depth ++ [ char ]
                }

            ',' ->
              let
                tabs = if isTup || isList
                       then []
                       else tab depth
              in
                { parse
                    | res =
                        res ++ tabs ++ [ char ]
                }

            '(' ->
                { charAdded | isTup = True }

            ')' ->
                { charAdded | isTup = False }

            '[' ->
                { charAdded | isList = True }

            ']' ->
                { charAdded | isList = False }

            _ ->
                charAdded


pretty : String -> String
pretty =
    String.toList
        >> List.foldl newlineOnOpen init
        >> .res
        >> String.fromList


log : String -> a -> a
log s a =
    toString a
        |> pretty
        |> Native.Pretty.log s
        |> always a

Pretty.js

/*global F2*/
/*eslint camelcase: 0*/
/*eslint no-unused-vars: 0*/

/*
 * Direct `String` access to `console.log`.
 * Needed because `Debug.log` doesn't pretty print.
 */

var _capillary$customer$Native_Pretty = (function () {
  function log (tag, value) {
    var msg = tag + ': ' + value
    console.log(msg)
    return value
  }
  return {
    log: F2(log),
		// expose newline and tabs special chars
    n: '\n',
    t: '\t'
  }
})()