Find the differences.elm

cleanInput : List TileDef -> String -> String
cleanInput defs str =
    let
        validLetters =
            List.map .letter defs
    in
        String.toUpper str
            |> String.toList
            |> List.filter (containsChar validLetters)
            |> String.fromList
            
compiles to             

var _user$project$Model$cleanInput = F2(
	function (defs, str) {
		var validLetters = A2(
			_elm_lang$core$List$map,
			function (_) {
				return _.letter;
			},
			defs);
		return A2(
			_user$project$Model$replaceBlanks,
			'?',
			_elm_lang$core$String$fromList(
				A2(
					_elm_lang$core$List$filter,
					_user$project$Model$containsChar(validLetters),
					_elm_lang$core$String$toList(
						_elm_lang$core$String$toUpper(
							A2(_user$project$Model$replaceBlanks, ' ', str))))));
	});


cleanInput2 : List TileDef -> String -> String
cleanInput2 defs str =
    let
        isValid =
            containsChar <|
                List.map .letter defs
    in
        String.toUpper str
            |> String.toList
            |> List.filter isValid
            |> String.fromList
            
compiles to 
            


var _user$project$Model$cleanInput2 = F2(
	function (defs, str) {
		var isValid = _user$project$Model$containsChar(
			A2(
				_elm_lang$core$List$map,
				function (_) {
					return _.letter;
				},
				defs));
		return _elm_lang$core$String$fromList(
			A2(
				_elm_lang$core$List$filter,
				isValid,
				_elm_lang$core$String$toList(
					_elm_lang$core$String$toUpper(str))));
	});

------------------------------------------------
cleanInput : List TileDef -> String -> String
cleanInput defs =
    let
        validLetters =
            List.map .letter defs
    in
        String.toUpper
            >> String.toList
            >> List.filter (containsChar validLetters)
            >> String.fromList

compiles to


var _user$project$Main$cleanInput = function (defs) {
	var validLetters = A2(
		_elm_lang$core$List$map,
		function (_) {
			return _.letter;
		},
		defs);
	return function (_p0) {
		return _elm_lang$core$String$fromList(
			A2(
				_elm_lang$core$List$filter,
				_user$project$Main$containsChar(validLetters),
				_elm_lang$core$String$toList(
					_elm_lang$core$String$toUpper(_p0))));
	};
};