Add toString.

doc/API.md

@@ -24,6 +24,7 @@
     - [shift() -> async](#shift---async)
     - [slice(start[, end]) -> Channel](#slicestart-end---channel)
     - [some(callbackfn[, thisArg])](#somecallbackfn-thisarg)
+    - [toString()](#tostring)
 - [Functional API](#functional-api)
 
 <!-- /TOC -->
@@ -305,6 +306,10 @@ Unlike in `Array`'s method, `callbackfn` is called with only one argument.
 `some` acts like the "exists" quantifier in mathematics. In particular, for an
 empty channel, it returns `false`.
 
+### toString() -> String
+
+Return `"Channel(n)"` where `n` is the length of the buffer.
+
 # Functional API
 
 There is a parallel API to support functional-style programming.  Every channel

lib/index.js

@@ -239,7 +239,9 @@ const Channel = function(bufferLength = 0) {
           }
         }
       }
-    }
+    },
+
+    toString: () => `Channel(${bufferLength})`
   });
 
   Object.defineProperty(readOnly, `value`, { get: () => lastValue });

test/index.js

@@ -356,6 +356,10 @@ describe(`Channel object`, function() {
     assert(!await Channel.of(1, 3, 5).some(even));
   });
 
+  it(`toString`, function() {
+    assert.equal(Channel(10).toString(), `Channel(10)`);
+  });
+
   it(`value`, async function() {
     const channel = Channel();
     (async () => {