Add functional API.

lib/index.js

@@ -311,4 +311,28 @@ Channel.select = (...methodPromises) => {
   return promise
 }
 
+// functional interface allowing full or partial application
+//
+// Channel.slice(10, Infinity, channel)
+//
+// or
+//
+// const skipTen = Channel.slice(10, Infinity)
+// skipTen(channel)
+
+const channel = Channel()
+const methods = Object.keys(channel).concat(Object.keys(channel.readOnly()))
+
+methods.forEach((method) => {
+  Channel[method] = (...args) => {
+    const arity = method === `slice`
+      ? 3
+      : channel[method].length
+
+    return args.length >= arity
+      ? args[arity - 1][method](...args.slice(0, arity - 1))
+      : (channel) => channel[method](...args)
+  }
+})
+
 module.exports = Object.freeze(Channel)