co - npm Package Compare versions

Comparing version 1.3.0 to 1.4.0

History.md

 
+1.4.0 / 2013-06-21 
+==================
+
+ * add promise support to joins
+ * add `yield generatorFunction` support
+ * add `yield generator` support
+ * add nested join support
+
 1.3.0 / 2013-06-10 
@@ -3,0 +11,0 @@ ==================

index.js

 
 /**
+ * toString reference.
+ */
+
+var toString = Object.prototype.toString;
+
+/**
  * Expose `co`.
@@ -18,3 +24,3 @@ */
   var args = [].slice.call(arguments, 1);
-  var gen = fn.apply(this, args);
+  var gen = isGenerator(fn) ? fn : fn.apply(this, args);
   var done;
@@ -56,8 +62,6 @@
 
-    // array (join)
-    if (Array.isArray(ret.value)) {
-      ret.value = exports.join(ret.value);
-    }
+    // normalize
+    ret.value = toThunk(ret.value);
 
-    // thunk
+    // run
     if ('function' == typeof ret.value) {
@@ -74,13 +78,4 @@ try {
 
-    // promise
-    if (ret.value && 'function' == typeof ret.value.then) {
-      ret.value.then(function(value) {
-        next(null, value);
-      }, next);
-
-      return;
-    }
-
-    // neither
-    next(new Error('yield a function or promise'));
+    // invalid
+    next(new Error('yield a function, promise, generator, or array'));
   }
@@ -143,2 +138,4 @@
       try {
+        fn = toThunk(fn);
+
         fn(function(err, res){
@@ -162,1 +159,69 @@ if (finished) return;
 };
+
+/**
+ * Convert `obj` into a normalized thunk.
+ *
+ * @param {Mixed} obj
+ * @return {Function}
+ * @api private
+ */
+
+function toThunk(obj) {
+  if (Array.isArray(obj)) obj = exports.join(obj);
+  if (isGeneratorFunction(obj)) obj = obj();
+  if (isGenerator(obj)) obj = co(obj);
+  if (isPromise(obj)) obj = promiseToThunk(obj);
+  return obj;
+}
+
+/**
+ * Convert `promise` to a thunk.
+ *
+ * @param {Object} promise
+ * @return {Function}
+ * @api private
+ */
+
+function promiseToThunk(promise) {
+  return function(fn){
+    promise.then(function(res) {
+      fn(null, res);
+    }, fn);
+  }
+}
+
+/**
+ * Check if `obj` is a promise.
+ *
+ * @param {Object} obj
+ * @return {Boolean}
+ * @api private
+ */
+
+function isPromise(obj) {
+  return obj && 'function' == typeof obj.then;
+}
+
+/**
+ * Check if `fn` is a generator.
+ *
+ * @param {Mixed} obj
+ * @return {Boolean}
+ * @api private
+ */
+
+function isGenerator(obj) {
+  return obj && '[object Generator]' == toString.call(obj);
+}
+
+/**
+ * Check if `fn` is a generator function.
+ *
+ * @param {Mixed} obj
+ * @return {Boolean}
+ * @api private
+ */
+
+function isGeneratorFunction(obj) {
+  return obj && obj.constructor && 'GeneratorFunction' == obj.constructor.name;
+}

package.json

 {
   "name": "co",
-  "version": "1.3.0",
+  "version": "1.4.0",
   "description": "generator async flow control goodness",
@@ -5,0 +5,0 @@ "keywords": ["async", "flow", "generator", "coro", "coroutine"],

Readme.md

@@ -14,2 +14,4 @@ # Co
 
+  Make sure to view the [examples](https://github.com/visionmedia/co/tree/master/examples).
+
 ## Installation
@@ -39,4 +41,22 @@
 })
+
+co(function *(){
+  var a = get('http://google.com');
+  var b = get('http://yahoo.com');
+  var c = get('http://cloudup.com');
+  var res = yield [a, b, c];
+  console.log(res);
+})
 ```
 
+## Yieldables
+
+  The "yieldable" objects currently supported are:
+
+  - promises
+  - thunks (functions)
+  - array (parallel execution)
+  - generators (delegation)
+  - generator functions (delegation)
+
 ## Thunks vs promises
@@ -105,5 +125,4 @@
 
-#### Nesting co() calls
+  You may also yield `Generator` objects to support nesting:
 
-  The `co()` function itself returns a thunk, this means you can nest appropriately:
 
@@ -123,3 +142,3 @@ ```js
 
-var foo = co(function *(){
+function *foo(){
   var a = yield size('.gitignore');
@@ -129,5 +148,5 @@ var b = yield size('Makefile');
   return [a, b, c];
-})
+}
 
-var bar = co(function *(){
+function *bar(){
   var a = yield size('examples/parallel.js');
@@ -137,7 +156,7 @@ var b = yield size('examples/nested.js');
   return [a, b, c];
-})
+}
 
 co(function *(){
-  var a = yield foo;
-  var b = yield bar;
+  var a = yield foo();
+  var b = yield bar();
   console.log(a);
@@ -148,34 +167,25 @@ console.log(b);
 
-  Or a variation of the same thing:
+  Or if the generator functions do not require arguments, simply `yield` the function:
 
 ```js
-var co = require('co');
-var fs = require('fs');
+var request = require('superagent');
 
-function size(file) {
-  return function(fn){
-    fs.stat(file, function(err, stat){
-      if (err) return fn(err);
-      fn(null, stat.size);
-    });
-  }
+var get = co.wrap(request.get);
+
+function *results() {
+  var a = yield get('http://google.com')
+  var b = yield get('http://yahoo.com')
+  var c = yield get('http://ign.com')
+  return [a.status, b.status, c.status]
 }
 
 co(function *(){
-  var a = yield co(function *(){
-    var a = yield size('.gitignore');
-    var b = yield size('Makefile');
-    var c = yield size('package.json');
-    return [a, b, c];
-  })
+  // 3 concurrent requests at a time
+  var a = yield results;
+  var b = yield results;
+  var c = yield results;
+  console.log(a, b, c);
 
-  var b = yield co(function *(){
-    var a = yield size('examples/parallel.js');
-    var b = yield size('examples/nested.js');
-    var c = yield size('examples/simple.js');
-    return [a, b, c];
-  })
-
-  console.log(a);
-  console.log(b);
+  // 9 concurrent requests
+  console.log(yield [results, results, results]);
 });
@@ -297,28 +307,18 @@ ```
 
-## FAQ
+  Nested joins may also be expressed as simple nested arrays:
 
-### How does this compare to taskjs?
-
-  - it's smaller
-  - it's not a scheduler
-  - you can use thunks (functions)
-  - you can use promises
-
-### Does it work with streams?
-
-  Not out of the box, but if you're willing to fight node a bit you can
-  wrestle streams into something usable:
-
 ```js
-co(function *(){
-  var res = yield get('http://google.com');
-  console.log('-> %s', res.status);
+var a = [
+  get('http://google.com'),
+  get('http://yahoo.com'),
+  get('http://ign.com')
+];
 
-  var buf;
-  while (buf = yield res.read()) {
-    console.log(buf.toString());
-  }
+var b = [
+  get('http://google.com'),
+  get('http://yahoo.com'),
+  get('http://ign.com')
+];
 
-  console.log('done');
-})
+console.log(yield [a, b]);
 ```
@@ -325,0 +325,0 @@

test/thunks.js

@@ -218,3 +218,3 @@
 
-        var msg = 'yield a function or promise';
+        var msg = 'yield a function, promise, generator, or array';
         errors.should.eql([msg, msg]);
@@ -221,0 +221,0 @@ done();

No alert changes

Improved metrics

Total package byte prevSize

29839

increased by14.72%

Number of package files

22

increased by15.79%

Lines of code

852

increased by21.89%

No dependency changes