diff --git a/src/components/Cell.js b/src/components/Cell.js
index dcb3fb9..918f971 100644
--- a/src/components/Cell.js
+++ b/src/components/Cell.js
@@ -1,3 +1,5 @@
+const { Stream } = require("../utils");
+
 class Cell {
   constructor(living = false, liveNeighbors = 0) {
     this.living = living;
@@ -22,21 +24,6 @@ class Cell {
   }
 }
 
-class Stream {
-  constructor(head, next) {
-    this.head = head;
-    this.tail = next;
-    this.memo = false;
-  }
-  get next() {
-    if (!this.memo) {
-      this.tail = this.tail();
-      this.memo = true;
-    }
-    return this.tail;
-  }
-}
-
 class CellStream extends Stream {
   constructor(head, next) {
     super(head, next);
diff --git a/src/components/GameField.js b/src/components/GameField.js
index 7e7e0f3..204e54c 100644
--- a/src/components/GameField.js
+++ b/src/components/GameField.js
@@ -1,6 +1,7 @@
-import { cellStream } from "./Cell";
+const { cellStream } = require("./Cell");
+const { Stream } = require("../utils");
 
-export default class GameField {
+class GameField {
   constructor({ fieldArray = [], fieldMap = {} }) {
     // seed = [ [] ]
     this.map = {};
@@ -19,8 +20,32 @@ export default class GameField {
   }
 }
 
+class FieldStream extends Stream {
+  constructor(head, next) {
+    super(head, next);
+  }
+  get map() {
+    return this.head.map;
+  }
+}
+
+const fieldStream = ({ fieldArray, fieldMap }) => {
+  return new FieldStream(new GameField({ fieldArray, fieldMap }), function () {
+    // calculate liveNeighbors for all cells on first next call
+
+    new FieldStream({}, function () {
+      // call .next on all Cells on second next call
+    });
+  });
+};
+
 // as a stream -> fieldStream => Stream(GameField, () => Stream(fieldStream.computeNeighbors(), () => Stream(fieldStream.setLiving()))
 
 // instantiate table (orientation of major and minor axis dependent on viewport)
 // const gameFields = new Array(1).fill(new GameField({}));
 // const container = document.getElementById("game-field");
+
+module.exports = {
+  GameField,
+  fieldStream,
+};
diff --git a/src/index.js b/src/index.js
index 3f7d44f..8f21f88 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,9 +1,8 @@
 import reset from "./styles/reset.css";
 import css from "./styles/style.css";
 // import Controls from './components/Controls';
-import GameField from "./components/GameField";
+const { GameField } = require("./components/GameField");
 (() => console.log("hello world!"))();
-
 // controls
 // -- state=idle ?
 // ---- rewind runs through gameHistory to current state - 1 step
diff --git a/src/test/GameField.test.js b/src/test/GameField.test.js
index 54db8e7..c9e040b 100644
--- a/src/test/GameField.test.js
+++ b/src/test/GameField.test.js
@@ -1,33 +1,55 @@
-import GameField from "../components/GameField";
+import { GameField, fieldStream } from "../components/GameField";
+
+const fieldArray = [
+  [0, 1, 0],
+  [1, 0, 1],
+];
+
+const fieldMap = {
+  "0-0": true,
+  "0-2": true,
+  "1-1": true,
+};
 
 describe("Game Field seeds living Cells with array", () => {
-  const gameArraySeed = new GameField({
-    fieldArray: [
-      [0, 1, 0],
-      [1, 0, 1],
-    ],
-  });
-  const gameMapSeed = new GameField({
-    fieldMap: {
-      "0-0": true,
-      "0-2": true,
-      "1-1": true,
-    },
-  });
+  const gameArraySeed = new GameField({ fieldArray });
+  const gameMapSeed = new GameField({ fieldMap });
+  const streamArraySeed = fieldStream({ fieldArray });
+  const streamMapSeed = fieldStream({ fieldMap });
+
   ["0-1", "1-0", "1-2"].forEach((key) => {
     test(`Array seed: ${key} should equal living Cell`, () => {
       expect(gameArraySeed.map[key].living).toEqual(true);
     });
+
     test(`Map seed: ${key} should equal undefined`, () => {
       expect(gameMapSeed.map[key]).toEqual(undefined);
     });
+
+    test(`Stream array seed: ${key} should equal living Cell`, () => {
+      expect(streamArraySeed.map[key].living).toEqual(true);
+    });
+
+    test(`Stream map seed: ${key} should equal undefined`, () => {
+      expect(streamMapSeed.map[key]).toEqual(undefined);
+    });
   });
+
   ["0-0", "0-2", "1-1"].forEach((key) => {
     test(`Array seed: ${key} should equal undefined`, () => {
       expect(gameArraySeed.map[key]).toEqual(undefined);
     });
+
     test(`Map seed: ${key} should equal living Cell`, () => {
       expect(gameMapSeed.map[key].living).toEqual(true);
     });
+
+    test(`Stream array seed: ${key} should equal undefined`, () => {
+      expect(streamArraySeed.map[key]).toEqual(undefined);
+    });
+
+    test(`Stream map seed: ${key} should equal living Cell`, () => {
+      expect(streamMapSeed.map[key].living).toEqual(true);
+    });
   });
 });
diff --git a/src/utils/index.js b/src/utils/index.js
new file mode 100644
index 0000000..ea07440
--- /dev/null
+++ b/src/utils/index.js
@@ -0,0 +1,18 @@
+class Stream {
+  constructor(head, next) {
+    this.head = head;
+    this.tail = next;
+    this.memo = false;
+  }
+  get next() {
+    if (!this.memo) {
+      this.tail = this.tail();
+      this.memo = true;
+    }
+    return this.tail;
+  }
+}
+
+module.exports = {
+  Stream,
+};