Improve examples

tshemsedinov · tshemsedinov · commit 84cd2e754635 · 2018-10-11T23:52:26.000+03:00
diff --git a/JavaScript/1-callback.js b/JavaScript/1-callback.js
@@ -3,5 +3,5 @@
 const add = (a, b) => a + b;
 const sum = (a, b, callback) => callback(a + b);
 
-console.log('Use add: ' + add(5, 2));
-sum(5, 2, console.log.bind(null, 'Use sum:'));
+console.log('add(5, 2) =', add(5, 2));
+sum(5, 2, console.log.bind(null, 'sum(5, 2) ='));
diff --git a/JavaScript/2-callback-use.js b/JavaScript/2-callback-use.js
@@ -3,7 +3,7 @@
 const fs = require('fs');
 
 fs.readFile('./1-callback.js', 'utf8', (err, data) => {
-  console.log({ lines: data.toString().split('\n').length });
+  console.log({ lines: data.split('\n').length });
 });
 
 console.log('end');
diff --git a/JavaScript/3-callback-named.js b/JavaScript/3-callback-named.js
@@ -2,10 +2,11 @@
 
 const fs = require('fs');
 
-const print = (err, data) => {
-  console.log({ lines: data.toString().split('\n').length });
+const print = (fileName, err, data) => {
+  console.log({ lines: data.split('\n').length });
 };
 
 const fileName = './1-callback.js';
 
-fs.readFile(fileName, 'utf8', print);
+const callback = print.bind(null, fileName);
+fs.readFile(fileName, 'utf8', callback);
diff --git a/JavaScript/4-callback-timer.js b/JavaScript/4-callback-timer.js
@@ -4,4 +4,6 @@ const fn = () => {
   console.log('Callback from from timer');
 };
 
-setTimeout(fn, 5000);
+const timeout = (interval, fn) => setTimeout(fn, interval);
+
+timeout(5000, fn);
diff --git a/JavaScript/5-timer-curry.js b/JavaScript/5-timer-curry.js
@@ -11,10 +11,10 @@ const fn = () => {
   console.log('Callback from from timer');
 };
 
-const setTimeoutCallbackLast = (timeout, fn) => setTimeout(fn, timeout);
+const timeout = (interval, fn) => setTimeout(fn, interval);
 
-const timer = curry(setTimeoutCallbackLast);
+const timer = curry(timeout);
 timer(2000)(fn);
 
-const timer5s = timer(2000);
-timer5s(fn);
+const timer2s = timer(2000);
+timer2s(fn);
diff --git a/JavaScript/6-listener.js b/JavaScript/6-listener.js
@@ -8,8 +8,8 @@ const iterate = (array, listener) => {
 
 const cities = ['Kiev', 'London', 'Beijing'];
 
-const each = city => {
-  console.log('City: ' + city);
+const print = city => {
+  console.log('City:', city);
 };
 
-iterate(cities, each);
+iterate(cities, print);
diff --git a/JavaScript/7-listener-timer.js b/JavaScript/7-listener-timer.js
@@ -2,6 +2,7 @@
 
 const iterate = (array, listener) => {
   let counter = 0;
+  // setImmediate or setTimeout(0) or process.nextTick
   setInterval(() => {
     listener(array[counter++]);
     if (counter >= array.length) counter = 0;
@@ -10,6 +11,6 @@ const iterate = (array, listener) => {
 
 const cities = ['Kiev', 'London', 'Beijing'];
 
-const fn = city => console.log('Next city: ' + city);
+const print = city => console.log('Next city:', city);
 
-iterate(cities, fn);
+iterate(cities, print);
diff --git a/JavaScript/9-event-emitter.js b/JavaScript/9-event-emitter.js
@@ -5,7 +5,7 @@ const events = require('events');
 const emitter = new events.EventEmitter();
 
 emitter.on('new city', city => {
-  console.log('Emitted city: ' + city);
+  console.log('Emitted city:', city);
 });
 
 emitter.on('data', array => {
diff --git a/JavaScript/a-deferred.js b/JavaScript/a-deferred.js
@@ -3,7 +3,7 @@
 const getConferences = () => {
   let onDone = null;
   const deferred = {
-    data: callback => onDone = callback
+    onData: callback => onDone = callback
   };
   setTimeout(() => {
     if (onDone) onDone(['Tehran', 'Yalta', 'Potsdam']);
@@ -17,7 +17,7 @@ const conferences = getConferences();
 
 console.log(conferences);
 
-conferences.data(list => {
+conferences.onData(list => {
   console.log(list);
 });
 
diff --git a/JavaScript/b-errors.js b/JavaScript/b-errors.js
@@ -7,7 +7,8 @@ const adder = value => {
     value += a;
     if (value >= add.maxValue) {
       setImmediate(() => {
-        add.maxEvent(new Error('max value reached'), value);
+        const err = new Error('max value reached');
+        add.maxEvent(err, value);
       });
     }
     return add;
@@ -25,10 +26,8 @@ const adder = value => {
 
 // error-first
 const maxReached = (err, value) => {
-  if (err) {
-    console.log('value: ' + value);
-    //throw err;
-  }
+  if (err) throw err;
+  console.log('value:', value);
 };
 
 try {
