added encode

Author: DanielJDufour

README.md

@@ -11,7 +11,13 @@ const decoded = decode(encoded);
 // [3, 3, 3, 3, 3, 8, 0, 0]
 ```
 ## encoding
-Coming Soon
+```javascript
+import encode from 'fast-rle/decode';
+
+const numbers = [3, 3, 3, 3, 3, 8, 0, 0];
+const encoded = decode(numbers);
+// [5, 3, 1, 8, 2, 0]
+```
 
 # support
 Post an issue at https://github.com/danieljdufour/fast-rle

encode.js

@@ -0,0 +1,21 @@
+const encode = nums => {
+    const encoded = [];
+    let current = nums[0];
+    let run_length = 1;
+    for (let i = 1; i < nums.length; i++) {
+        const num = nums[i];
+        if (num === current) {
+            run_length++;
+        } else {
+            encoded.push(run_length);
+            encoded.push(current);
+            current = num;
+            run_length = 1;
+        }
+    }
+    encoded.push(run_length);
+    encoded.push(current);
+    return encoded;
+};
+
+module.exports = encode;

index.js

@@ -1,3 +1,4 @@
 module.exports = {
-  decode: require('./decode')
+  decode: require('./decode'),
+  encode: require('./encode')
 };

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "fast-rle",
-  "version": "0.0.0",
+  "version": "0.0.1",
   "description": "Fast Run Length Encoder and Decoder",
   "main": "index.js",
   "scripts": {

package.json

@@ -1,9 +1,16 @@
 const test = require('ava');
 const decode = require('./decode');
+const encode = require('./encode');
+
+const decoded = [3, 3, 3, 3, 3, 8, 0, 0];
+const encoded = [5, 3, 1, 8, 2, 0];
 
 test('decode', t => {
-  const encoded = [5, 3, 1, 8, 2, 0];
-  const decoded = decode(encoded);
-  const expected = [3, 3, 3, 3, 3, 8, 0, 0];
-  t.deepEqual(decoded, expected);
+  const actual = decode(encoded);
+  t.deepEqual(actual, decoded);
+});
+
+test('encoded', t => {
+  const actual = encode(decoded);
+  t.deepEqual(actual, encoded);
 });