Added usage notes to README

README.md

@@ -5,7 +5,7 @@ Multi-hash
 [![Coverage Status](https://coveralls.io/repos/tinybike/multi-hash/badge.svg?branch=master&service=github)](https://coveralls.io/github/tinybike/multi-hash?branch=master)
 [![npm version](https://badge.fury.io/js/multi-hash.svg)](http://badge.fury.io/js/multi-hash)
 
-Multi-hash encoder/decoder.
+Multi-hash encoder/decoder.  Only supports sha256 multi-hash (the [IPFS](https://ipfs.io/) default) for now; will add more soon.
 
 Usage
 -----
@@ -20,6 +20,19 @@ A minified, browserified file `dist/multihash.min.js` is included for use in the
 ```html
 <script src="dist/multihash.min.js" type="text/javascript"></script>
 ```
+Multi-hash includes `encode` and `decode` functions.  `encode` accepts a 32-byte buffer or hex-encoded string, and converts it to a base58-encoded multi-hash string.
+```javascript
+var hex = "4afeb08a2bf63b8e42f4b67bd92dbf7e4a23f991c7acf0236a9d1c04462db278";
+
+var ipfsHash = multihash.encode(hex);
+// ipfsHash: QmPH4nmLYxgWyq9FqpzvxAEPZ5ZdwGZjmvusLqPDCk7mu1
+```
+`decode` accepts a base58-encoded multi-hash string, and converts it to a 32-byte buffer with the multi-hash prefix removed.
+```javascript
+var buf = multihash.decode(ipfsHash);
+// buf: <Buffer 4a fe b0 8a 2b f6 3b 8e 42 f4 b6 7b d9 2d bf 7e 4a 23 f9 91 c7
+//              ac f0 23 6a 9d 1c 04 46 2d b2 78>
+```
 
 Tests
 -----

dist/multi-hash.js

@@ -17,24 +17,6 @@ var bs58 = require("bs58");
 
 module.exports = {
 
-    /**
-     * Remove multi-hash tag (assuming sha256, the IPFS default):
-     * 1. Remove leading two characters (Qm)
-     * 2. Decode base58 string to 33 byte array
-     * 3. Remove the leading byte, which is part of the hash tag
-     * @param {string|Buffer} hash Base58-encoded sha256 hash digest.
-     * @return {Buffer} 32-byte array with multihash tag removed.
-     */
-    decode: function (hash) {
-        if (hash && hash.constructor === String && hash.slice(0, 2) === "Qm") {
-            if (hash.length !== 46) {
-                throw new Error("length error: expected hash+tag length of 46");
-            }
-            return new Buffer(bs58.decode(hash.slice(2)).splice(1));
-        }
-        throw new Error("unsupported format: expected base58 string");
-    },
-
     /**
      * Add sha256 multi-hash tag to hex-encoded hash and convert to base58.
      * (Prefix 1 if leading byte > 60; prefix 2 otherwise.)
@@ -56,6 +38,24 @@ module.exports = {
             return "Qm" + bs58.encode(new Buffer(hex, "hex"));
         }
         throw new Error("unsupported format: expected hex string");
+    },
+
+    /**
+     * Remove multi-hash tag (assuming sha256, the IPFS default):
+     * 1. Remove leading two characters (Qm)
+     * 2. Decode base58 string to 33 byte array
+     * 3. Remove the leading byte, which is part of the hash tag
+     * @param {string|Buffer} hash Base58-encoded sha256 hash digest.
+     * @return {Buffer} 32-byte array with multihash tag removed.
+     */
+    decode: function (hash) {
+        if (hash && hash.constructor === String && hash.slice(0, 2) === "Qm") {
+            if (hash.length !== 46) {
+                throw new Error("length error: expected hash+tag length of 46");
+            }
+            return new Buffer(bs58.decode(hash.slice(2)).splice(1));
+        }
+        throw new Error("unsupported format: expected base58 string");
     }
 
 };

index.js

@@ -9,24 +9,6 @@ var bs58 = require("bs58");
 
 module.exports = {
 
-    /**
-     * Remove multi-hash tag (assuming sha256, the IPFS default):
-     * 1. Remove leading two characters (Qm)
-     * 2. Decode base58 string to 33 byte array
-     * 3. Remove the leading byte, which is part of the hash tag
-     * @param {string|Buffer} hash Base58-encoded sha256 hash digest.
-     * @return {Buffer} 32-byte array with multihash tag removed.
-     */
-    decode: function (hash) {
-        if (hash && hash.constructor === String && hash.slice(0, 2) === "Qm") {
-            if (hash.length !== 46) {
-                throw new Error("length error: expected hash+tag length of 46");
-            }
-            return new Buffer(bs58.decode(hash.slice(2)).splice(1));
-        }
-        throw new Error("unsupported format: expected base58 string");
-    },
-
     /**
      * Add sha256 multi-hash tag to hex-encoded hash and convert to base58.
      * (Prefix 1 if leading byte > 60; prefix 2 otherwise.)
@@ -48,6 +30,24 @@ module.exports = {
             return "Qm" + bs58.encode(new Buffer(hex, "hex"));
         }
         throw new Error("unsupported format: expected hex string");
+    },
+
+    /**
+     * Remove multi-hash tag (assuming sha256, the IPFS default):
+     * 1. Remove leading two characters (Qm)
+     * 2. Decode base58 string to 33 byte array
+     * 3. Remove the leading byte, which is part of the hash tag
+     * @param {string|Buffer} hash Base58-encoded sha256 hash digest.
+     * @return {Buffer} 32-byte array with multihash tag removed.
+     */
+    decode: function (hash) {
+        if (hash && hash.constructor === String && hash.slice(0, 2) === "Qm") {
+            if (hash.length !== 46) {
+                throw new Error("length error: expected hash+tag length of 46");
+            }
+            return new Buffer(bs58.decode(hash.slice(2)).splice(1));
+        }
+        throw new Error("unsupported format: expected base58 string");
     }
 
 };

package.json

@@ -1,6 +1,6 @@
 {
   "name": "multi-hash",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "Multi-hash encoder/decoder",
   "main": "index.js",
   "scripts": {