diff --git a/src/_h5ai/public/js/lib/core/event.js b/src/_h5ai/public/js/lib/core/event.js
index 16f16e1f..7b7b0c3f 100644
--- a/src/_h5ai/public/js/lib/core/event.js
+++ b/src/_h5ai/public/js/lib/core/event.js
@@ -1,5 +1,4 @@
-const isStr = x => typeof x === 'string';
-const isFn = x => typeof x === 'function';
+const {isStr, isFn} = require('../lo');
 
 const subscriptions = {};
 
diff --git a/src/_h5ai/public/js/lib/core/format.js b/src/_h5ai/public/js/lib/core/format.js
index 85901f3a..74747322 100644
--- a/src/_h5ai/public/js/lib/core/format.js
+++ b/src/_h5ai/public/js/lib/core/format.js
@@ -1,4 +1,4 @@
-const isNum = x => typeof x === 'number';
+const {isNum} = require('../lo');
 
 const decimalMetric = {
     t: 1000.0,
diff --git a/src/_h5ai/public/js/lib/core/location.js b/src/_h5ai/public/js/lib/core/location.js
index f7813cf1..4b8122e1 100644
--- a/src/_h5ai/public/js/lib/core/location.js
+++ b/src/_h5ai/public/js/lib/core/location.js
@@ -1,13 +1,10 @@
+const {each, values, isFn, difference} = require('../lo');
 const {win} = require('../globals');
 const {request} = require('../server');
 const allsettings = require('./settings');
 const event = require('./event');
 const notification = require('../view/notification');
 
-const each = (obj, fn) => Object.keys(obj).forEach(key => fn(obj[key], key));
-const values = obj => Object.keys(obj).map(key => obj[key]);
-const isFn = x => typeof x === 'function';
-const difference = (arr1, arr2) => arr1.filter(x => arr2.indexOf(x) < 0);
 
 const doc = win.document;
 const settings = Object.assign({
diff --git a/src/_h5ai/public/js/lib/core/resource.js b/src/_h5ai/public/js/lib/core/resource.js
index 85de53f3..64db4005 100644
--- a/src/_h5ai/public/js/lib/core/resource.js
+++ b/src/_h5ai/public/js/lib/core/resource.js
@@ -1,8 +1,7 @@
+const {includes} = require('../lo');
 const config = require('../config');
 const settings = require('./settings');
 
-const includes = (arr, x) => arr.indexOf(x) >= 0;
-
 const imagesHref = settings.publicHref + 'images/';
 const uiHref = imagesHref + 'ui/';
 const themesHref = imagesHref + 'themes/';
diff --git a/src/_h5ai/public/js/lib/core/types.js b/src/_h5ai/public/js/lib/core/types.js
index 256324ee..c9798200 100644
--- a/src/_h5ai/public/js/lib/core/types.js
+++ b/src/_h5ai/public/js/lib/core/types.js
@@ -1,8 +1,6 @@
+const {each, map} = require('../lo');
 const config = require('../config');
 
-const each = (obj, fn) => Object.keys(obj).forEach(key => fn(obj[key], key));
-const map = (arr, fn) => Array.from(arr, fn);
-
 const reEndsWithSlash = /\/$/;
 const regexps = {};
 
diff --git a/src/_h5ai/public/js/lib/lo.js b/src/_h5ai/public/js/lib/lo.js
new file mode 100644
index 00000000..7d396723
--- /dev/null
+++ b/src/_h5ai/public/js/lib/lo.js
@@ -0,0 +1,50 @@
+const tof = (x, str) => typeof x === str;
+const isStr = x => tof(x, 'string');
+const isFn = x => tof(x, 'function');
+const isNum = x => tof(x, 'number');
+const keys = obj => {
+    if (!obj || isStr(obj)) {
+        return [];
+    }
+    if (obj.hasOwnProperty('length')) {
+        obj = Array.from(obj);
+    }
+    return Object.keys(obj);
+};
+const values = obj => keys(obj).map(key => obj[key]);
+const each = (obj, fn) => keys(obj).forEach(key => fn(obj[key], key));
+const filter = (obj, fn) => values(obj).filter(fn);
+const map = (obj, fn) => values(obj).map(fn);
+const includes = (obj, x) => values(obj).indexOf(x) >= 0;
+const difference = (obj1, obj2) => {
+    obj2 = values(obj2);
+    return filter(obj1, x => obj2.indexOf(x) < 0);
+};
+const intersection = (obj1, obj2) => {
+    obj2 = values(obj2);
+    return filter(obj1, x => obj2.indexOf(x) >= 0);
+};
+const sortBy = (obj, sel) => {
+    const selFn = isFn(sel) ? sel : x => x[sel];
+    const cmpFn = (x, y) => {
+        x = selFn(x);
+        y = selFn(y);
+        return x < y ? -1 : x > y ? 1 : 0;
+    };
+    return values(obj).sort(cmpFn);
+};
+
+module.exports = {
+    isStr,
+    isFn,
+    isNum,
+    keys,
+    values,
+    each,
+    filter,
+    map,
+    includes,
+    difference,
+    intersection,
+    sortBy
+};
diff --git a/src/_h5ai/public/js/lib/model/item.js b/src/_h5ai/public/js/lib/model/item.js
index dfa4ee21..9468eaf4 100644
--- a/src/_h5ai/public/js/lib/model/item.js
+++ b/src/_h5ai/public/js/lib/model/item.js
@@ -1,4 +1,4 @@
-const {lo} = require('../globals');
+const {keys, each, filter, sortBy, isFn, isStr, isNum} = require('../lo');
 const server = require('../server');
 const location = require('../core/location');
 const settings = require('../core/settings');
@@ -49,9 +49,9 @@ function splitPath(sequence) { // eslint-disable-line consistent-return
 }
 
 function getItem(options) {
-    if (lo.isString(options)) {
+    if (isStr(options)) {
         options = {href: options};
-    } else if (!options || !lo.isString(options.href)) {
+    } else if (!options || !isStr(options.href)) {
         return null;
     }
 
@@ -63,10 +63,10 @@ function getItem(options) {
 
     const item = cache[href] || new Item(href); // eslint-disable-line no-use-before-define
 
-    if (lo.isNumber(options.time)) {
+    if (isNum(options.time)) {
         item.time = options.time;
     }
-    if (lo.isNumber(options.size)) {
+    if (isNum(options.size)) {
         item.size = options.size;
     }
     if (options.managed) {
@@ -89,7 +89,7 @@ function removeItem(absHref) {
         if (item.parent) {
             delete item.parent.content[item.absHref];
         }
-        lo.each(item.content, child => {
+        each(item.content, child => {
             removeItem(child.absHref);
         });
     }
@@ -98,7 +98,7 @@ function removeItem(absHref) {
 function fetchContent(absHref, callback) {
     const item = getItem(absHref);
 
-    if (!lo.isFunction(callback)) {
+    if (!isFn(callback)) {
         callback = () => undefined;
     }
 
@@ -107,7 +107,7 @@ function fetchContent(absHref, callback) {
     } else {
         server.request({action: 'get', items: {href: item.absHref, what: 1}}).then(response => {
             if (response.items) {
-                lo.each(response.items, jsonItem => {
+                each(response.items, jsonItem => {
                     getItem(jsonItem);
                 });
             }
@@ -135,13 +135,13 @@ function Item(absHref) {
     if (split.parent) {
         this.parent = getItem(split.parent);
         this.parent.content[this.absHref] = this;
-        if (lo.keys(this.parent.content).length > 1) {
+        if (keys(this.parent.content).length > 1) {
             this.parent.isContentFetched = true;
         }
     }
 }
 
-lo.extend(Item.prototype, {
+Object.assign(Item.prototype, {
     isFolder() {
         return reEndsWithSlash.test(this.absHref);
     },
@@ -168,7 +168,7 @@ lo.extend(Item.prototype, {
     },
 
     isEmpty() {
-        return lo.keys(this.content).length === 0;
+        return keys(this.content).length === 0;
     },
 
     fetchContent(callback) {
@@ -188,7 +188,7 @@ lo.extend(Item.prototype, {
     },
 
     getSubfolders() {
-        return lo.sortBy(lo.filter(this.content, item => {
+        return sortBy(filter(this.content, item => {
             return item.isFolder();
         }), item => {
             return item.label.toLowerCase();
@@ -199,7 +199,7 @@ lo.extend(Item.prototype, {
         let folders = 0;
         let files = 0;
 
-        lo.each(this.content, item => {
+        each(this.content, item => {
             if (item.isFolder()) {
                 folders += 1;
             } else {
diff --git a/src/_h5ai/public/js/lib/server.js b/src/_h5ai/public/js/lib/server.js
index a65c9e4e..13148c65 100644
--- a/src/_h5ai/public/js/lib/server.js
+++ b/src/_h5ai/public/js/lib/server.js
@@ -1,6 +1,5 @@
 const {jq} = require('./globals');
-
-const each = (obj, fn) => Object.keys(obj).forEach(key => fn(obj[key], key));
+const {each} = require('./lo');
 
 const request = data => {
     return new Promise(resolve => {
diff --git a/src/_h5ai/public/js/lib/view/view.js b/src/_h5ai/public/js/lib/view/view.js
index 075c7633..a1688001 100644
--- a/src/_h5ai/public/js/lib/view/view.js
+++ b/src/_h5ai/public/js/lib/view/view.js
@@ -1,4 +1,5 @@
-const {jq, lo} = require('../globals');
+const {each, map, includes, intersection} = require('../lo');
+const {jq} = require('../globals');
 const event = require('../core/event');
 const format = require('../core/format');
 const location = require('../core/location');
@@ -9,7 +10,7 @@ const base = require('./base');
 
 const modes = ['details', 'grid', 'icons'];
 const sizes = [20, 40, 60, 80, 100, 150, 200, 250, 300, 350, 400];
-const settings = lo.extend({
+const settings = Object.assign({
     binaryPrefix: false,
     hideFolders: false,
     hideParentFolder: false,
@@ -18,7 +19,7 @@ const settings = lo.extend({
     sizes
 }, allsettings.view);
 const sortedSizes = settings.sizes.sort((a, b) => a - b);
-const checkedModes = lo.intersection(settings.modes, modes);
+const checkedModes = intersection(settings.modes, modes);
 const storekey = 'view';
 const tplView =
         `<div id="view">
@@ -78,7 +79,7 @@ function createStyles(size) {
 }
 
 function addCssStyles() {
-    const styles = lo.map(sortedSizes, size => createStyles(size));
+    const styles = map(sortedSizes, size => createStyles(size));
     styles.push(`#view .icon img {max-width: ${settings.maxIconSize}px; max-height: ${settings.maxIconSize}px;}`);
     jq('<style/>').text(styles.join('\n')).appendTo('head');
 }
@@ -88,11 +89,11 @@ function set(mode, size) {
 
     mode = mode || stored && stored.mode;
     size = size || stored && stored.size;
-    mode = lo.includes(settings.modes, mode) ? mode : settings.modes[0];
-    size = lo.includes(settings.sizes, size) ? size : settings.sizes[0];
+    mode = includes(settings.modes, mode) ? mode : settings.modes[0];
+    size = includes(settings.sizes, size) ? size : settings.sizes[0];
     store.put(storekey, {mode, size});
 
-    lo.each(checkedModes, m => {
+    each(checkedModes, m => {
         if (m === mode) {
             $view.addClass('view-' + m);
         } else {
@@ -100,7 +101,7 @@ function set(mode, size) {
         }
     });
 
-    lo.each(sortedSizes, s => {
+    each(sortedSizes, s => {
         if (s === size) {
             $view.addClass('view-size-' + s);
         } else {
@@ -194,15 +195,11 @@ function checkHint() {
 }
 
 function setItems(items) {
-    const removed = lo.map($items.find('.item'), item => {
-        return jq(item).data('item');
-    });
+    const removed = map($items.find('.item'), el => jq(el).data('item'));
 
     $items.find('.item').remove();
 
-    lo.each(items, e => {
-        $items.append(createHtml(e));
-    });
+    each(items, item => $items.append(createHtml(item)));
 
     base.$content.scrollLeft(0).scrollTop(0);
     checkHint();
@@ -210,11 +207,11 @@ function setItems(items) {
 }
 
 function changeItems(add, remove) {
-    lo.each(add, item => {
+    each(add, item => {
         createHtml(item).hide().appendTo($items).fadeIn(400);
     });
 
-    lo.each(remove, item => {
+    each(remove, item => {
         item.$view.fadeOut(400, () => {
             item.$view.remove();
         });
@@ -240,7 +237,7 @@ function onLocationChanged(item) {
         items.push(item.parent);
     }
 
-    lo.each(item.content, child => {
+    each(item.content, child => {
         if (!(child.isFolder() && settings.hideFolders)) {
             items.push(child);
         }
@@ -253,7 +250,7 @@ function onLocationChanged(item) {
 function onLocationRefreshed(item, added, removed) {
     const add = [];
 
-    lo.each(added, child => {
+    each(added, child => {
         if (!(child.isFolder() && settings.hideFolders)) {
             add.push(child);
         }
diff --git a/src/_h5ai/public/js/lib/view/viewmode.js b/src/_h5ai/public/js/lib/view/viewmode.js
index 542bdf8b..92a13ff5 100644
--- a/src/_h5ai/public/js/lib/view/viewmode.js
+++ b/src/_h5ai/public/js/lib/view/viewmode.js
@@ -1,4 +1,5 @@
-const {jq, lo} = require('../globals');
+const {each} = require('../lo');
+const {jq} = require('../globals');
 const event = require('../core/event');
 const resource = require('../core/resource');
 const allsettings = require('../core/settings');
@@ -7,7 +8,7 @@ const base = require('./base');
 const view = require('./view');
 
 
-const settings = lo.extend({
+const settings = Object.assign({
     modeToggle: false
 }, allsettings.view);
 const tplSettings =
@@ -29,7 +30,7 @@ let sizes;
 function onChanged(mode, size) {
     jq('#viewmode-settings .mode').removeClass('active');
     jq('#viewmode-' + mode).addClass('active');
-    jq('#viewmode-size').val(lo.indexOf(sizes, size));
+    jq('#viewmode-size').val(sizes.indexOf(size));
 
     if (settings.modeToggle === 'next') {
         mode = modes[(modes.indexOf(mode) + 1) % modes.length];
@@ -45,7 +46,7 @@ function addSettings() {
     const $viewBlock = jq(tplSettings);
 
     if (modes.length > 1) {
-        lo.each(modes, mode => {
+        each(modes, mode => {
             jq(tplMode.replace(/\[MODE\]/g, mode))
                 .on('click', () => {
                     view.setMode(mode);