diff --git a/README.md b/README.md
index 2cf29e0..a7f327c 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,7 @@ Ronin helpers are keywords that facilitates adding coordinates from the canvas i
 - `(condense pixel q)` Condense the data of pixels.
 - `(balance pixel q)` Change the color balance of pixels.
 - `(concat ...items)` Concat multiple strings.
+- `(split string char)` Split string at character.
 - `(add ...args)` Adds values.
 - `(sub ...args)` Subtracts values.
 - `(mul ...args)` Multiplies values.
@@ -102,9 +103,10 @@ Ronin helpers are keywords that facilitates adding coordinates from the canvas i
 - `(eq a b)` Returns true if a is equal to b, else false.
 - `(and a b ...rest)` Returns true if all conditions are true.
 - `(or a b ...rest)` Returns true if at least one condition is true.
-- `(map fn arr)` 
-- `(filter fn arr)` 
-- `(reduce fn arr acc)` 
+- `(each arr fn)` Run a function for each element in a list.
+- `(map arr fn)` Run a function on each element in a list.
+- `(filter arr fn)` Remove from list, when function returns false.
+- `(reduce arr fn acc)` 
 - `(len item)` Returns the length of a list.
 - `(first arr)` Returns the first item of a list.
 - `(last arr)` Returns the last
@@ -124,9 +126,8 @@ Ronin helpers are keywords that facilitates adding coordinates from the canvas i
 - `(dirpath ~path)` Returns the path of a directory.
 - `(filepath ~path)` Returns the path of a file.
 - `(exit ~force)` Exits Ronin.
-- `(echo ...args)` 
-- `(table arg)` 
-- `(debug arg)` 
+- `(echo ...args)` Print arguments to interface.
+- `(debug arg)` Print arguments to console.
 - `(time ~rate)` Returns timestamp in milliseconds.
 - `(js)` Javascript interop.
 - `(on event f)` Triggers on event.
diff --git a/desktop/sources/scripts/library.js b/desktop/sources/scripts/library.js
index 0c83082..5b43e57 100644
--- a/desktop/sources/scripts/library.js
+++ b/desktop/sources/scripts/library.js
@@ -215,6 +215,10 @@ function Library (ronin) {
     return items.reduce((acc, item) => { return `${acc}${item}` }, '')
   }
 
+  this.split = function (string, char) { // Split string at character.
+    return string.split(char)
+  }
+
   // Math
 
   this.add = (...args) => { // Adds values.
@@ -320,14 +324,21 @@ function Library (ronin) {
 
   // Arrays
 
-  this.map = async (fn, arr) => {
+  this.each = async (arr, fn) => { // Run a function for each element in a list.
     for (let i = 0; i < arr.length; i++) {
       const arg = arr[i]
       await fn(arg)
     }
   }
 
-  this.filter = (fn, arr) => {
+  this.map = async (arr, fn) => { // Run a function on each element in a list.
+    for (let i = 0; i < arr.length; i++) {
+      const arg = arr[i]
+      arr[i] = await fn(arg)
+    }
+  }
+
+  this.filter = (arr, fn) => { // Remove from list, when function returns false.
     const list = Array.from(arr)
     return Promise.all(list.map((element, index) => fn(element, index, list)))
       .then(result => {
@@ -337,7 +348,7 @@ function Library (ronin) {
       })
   }
 
-  this.reduce = async (fn, arr, acc) => {
+  this.reduce = async (arr, fn, acc) => {
     const length = arr.length
     let result = acc === undefined ? subject[0] : acc
     for (let i = acc === undefined ? 1 : 0; i < length; i++) {
@@ -463,17 +474,12 @@ function Library (ronin) {
     ronin.source.quit(force)
   }
 
-  this.echo = (...args) => {
+  this.echo = (...args) => { // Print arguments to interface.
     ronin.log(args)
     return args
   }
 
-  this.table = (arg) => {
-    console.table(arg)
-    return arg
-  }
-
-  this.debug = (arg) => {
+  this.debug = (arg) => { // Print arguments to console.
     console.log(arg)
     return arg
   }
diff --git a/examples/batch/folder.lisp b/examples/batch/folder.lisp
new file mode 100644
index 0000000..ddf89cf
--- /dev/null
+++ b/examples/batch/folder.lisp
@@ -0,0 +1,24 @@
+; open every file in a folder.
+(defn filter-jpg 
+  (file-name) 
+  (eq 
+    (last 
+      (split file-name ".")) "jpg"))
+;
+(def images 
+  (filter 
+    (dir) filter-jpg))
+;
+(debug 
+  (concat "Found: " 
+    (len images)))
+;
+(defn image-operation 
+  (file-name) 
+  (
+    (def file-path 
+      (concat 
+        (dirpath) "/" file-name)) 
+    (open file-path)))
+;
+(each images image-operation)
\ No newline at end of file
diff --git a/examples/benchmark/general.lisp b/examples/benchmark/general.lisp
index dc232c1..e240340 100644
--- a/examples/benchmark/general.lisp
+++ b/examples/benchmark/general.lisp
@@ -35,9 +35,9 @@
   (test "range simple" (range 0 4) (0 1 2 3 4))
   (test "range with step" (range 0 4 2) (0 2 4))
   (test "range with negative step" (range 0 -4 -1) (0 -1 -2 -3 -4))
-  (test "map" (map (λ (a) (add 1 a)) (1 2 3)) (2 3 4))
-  (test "filter" (filter (λ (a) (eq 0 (mod a 2))) (2 3 4 5 6)) (2 4 6))
-  (test "reduce" (reduce (λ (acc val) (add acc val)) (1 2 3) 4) 10)
+  (test "map" (map (1 2 3) (λ (a) (add 1 a))) (2 3 4))
+  (test "filter" (filter (2 3 4 5 6)) (λ (a) (eq 0 (mod a 2))) (2 4 6))
+  (test "reduce" (reduce (1 2 3) (λ (acc val) (add acc val)) 4) 10)
 
 ; Scope
 
diff --git a/examples/demo/dejong.lisp b/examples/demo/dejong.lisp
index d373008..994e288 100644
--- a/examples/demo/dejong.lisp
+++ b/examples/demo/dejong.lisp
@@ -16,11 +16,11 @@
 
 (defn dejong (r a b c d)
   (reduce  
+    (range 0 r)
     (λ (acc val)
       (first (
         (_dejong (first acc) (last acc) a b c d)
       )))
-    (range 0 r)
     (2 1)
   )
 )