Merge pull request coffeescript-cookbook#28 from phlipper/wanted-recipes

Added some "Wanted recipes"

Author: blowmage

authors.md

@@ -15,6 +15,7 @@ The following people are totally rad and awesome because they have contributed r
 * Aaron Weinberger _[email protected]_
 * James C. Holder _[email protected]_
 * Jason Giedymin _[email protected]_
+* Phil Cohen _[email protected]_
 * ...You! What are you waiting for? Check out the [contributing](/contributing) section and get cracking!
 
 # Developers

chapters/arrays/creating-a-string-from-an-array.md

@@ -0,0 +1,21 @@
+---
+layout: recipe
+title: Creating a String from an Array
+chapter: Arrays
+---
+## Problem
+
+You want to create a string from an array.
+
+## Solution
+
+Use JavaScript's Array toString() method:
+
+{% highlight coffeescript %}
+["one", "two", "three"].toString()
+# => 'three,two,one'
+{% endhighlight %}
+
+## Discussion
+
+`toString()` is a standard JavaScript method. Don't forget the parentheses.

chapters/arrays/removing-duplicate-elements-from-arrays.md

@@ -0,0 +1,24 @@
+---
+layout: recipe
+title: Removing duplicate elements from Arrays
+chapter: Arrays
+---
+## Problem
+
+You want to remove duplicate elements from an array.
+
+## Solution
+
+{% highlight coffeescript %}
+Array::unique = ->
+  output = {}
+  output[@[key]] = @[key] for key in [0...@length]
+  value for key, value of output
+
+[1,1,2,2,2,3,4,5,6,6,6,"a","a","b","d","b","c"].unique()
+# => [ 1, 2, 3, 4, 5, 6, 'a', 'b', 'd', 'c' ]
+{% endhighlight %}
+
+## Discussion
+
+There are many implementations of the `unique` method in JavaScript. This one is based on "The fastest method to find unique items in array" found [here](http://www.shamasis.net/2009/09/fast-algorithm-to-find-unique-items-in-javascript-array/).

chapters/regular_expressions/replacing-html-tags-with-html-named-entities.md

@@ -0,0 +1,25 @@
+---
+layout: recipe
+title: Replacing HTML tags with HTML named entities
+chapter: Regular Expressions
+---
+## Problem
+
+You need to replace HTML tags with named entities:
+
+`<br/> => &lt;br/&gt;`
+
+## Solution
+
+{% highlight coffeescript %}
+htmlEncode = (str) ->
+  str.replace /[&<>"']/g, ($0) ->
+    "&" + {"&":"amp", "<":"lt", ">":"gt", '"':"quot", "'":"#39"}[$0] + ";"
+
+htmlEncode('<a href="http://bn.com">Barnes & Noble</a>')
+# => '&lt;a href=&quot;http://bn.com&quot;&gt;Barnes &amp; Noble&lt;/a&gt;'
+{% endhighlight %}
+
+## Discussion
+
+There are probably better ways to implement the above method.

chapters/strings/lowercasing-a-string.md

@@ -0,0 +1,45 @@
+---
+layout: recipe
+title: Lowercasing a String
+chapter: Strings
+---
+## Problem
+
+You want to lowercase a string.
+
+## Solution
+
+Use JavaScript's String toLowerCase() method:
+
+{% highlight coffeescript %}
+"ONE TWO THREE".toLowerCase()
+# => 'one two three'
+{% endhighlight %}
+
+## Discussion
+
+`toLowerCase()` is a standard JavaScript method. Don't forget the parentheses.
+
+### Syntax Sugar
+
+You can add some Ruby-like syntax sugar with the following shortcut:
+
+{% highlight coffeescript %}
+String::downcase = -> @toLowerCase()
+"ONE TWO THREE".downcase()
+# => 'one two three'
+{% endhighlight %}
+
+The snippet above demonstrates a few features of CoffeeScript:
+
+* The double-colon `::` is shorthand for saying `.prototype.`
+* The "at" sign `@` is shorthand for saying `this.`
+
+The code above compiles in to the following JavaScript:
+
+{% highlight javascript %}
+String.prototype.downcase = function() {
+  return this.toLowerCase();
+};
+"ONE TWO THREE".downcase();
+{% endhighlight %}

chapters/strings/trimming-whitespace-from-a-string.md

@@ -0,0 +1,65 @@
+---
+layout: recipe
+title: Trimming whitespace from a String
+chapter: Strings
+---
+## Problem
+
+You want to trim whitespace from a string.
+
+## Solution
+
+Use JavaScript's Regular Expression support to replace whitespace.
+
+To trim leading and trailing whitespace, use the following:
+
+{% highlight coffeescript %}
+"  padded string  ".replace /^\s+|\s+$/g, ""
+# => 'padded string'
+{% endhighlight %}
+
+To trim only leading whitespace, use the following:
+
+{% highlight coffeescript %}
+"  padded string  ".replace /^\s+/g, ""
+# => 'padded string  '
+{% endhighlight %}
+
+To trim only trailing whitespace, use the following:
+
+{% highlight coffeescript %}
+"  padded string  ".replace /\s+$/g, ""
+# => '  padded string'
+{% endhighlight %}
+
+## Discussion
+
+Opera, Firefox and Chrome all have a native string prototype `trim` method, and the other browsers could add one as well. For this particular method, I would use the built-in method where possible:
+
+{% highlight coffeescript %}
+trim = (val) ->
+  if String::trim? then val.trim() else val.replace /^\s+|\s+$/g, ""
+
+trim "  padded string  "
+# => 'padded string'
+{% endhighlight %}
+
+
+### Syntax Sugar
+
+You can add some Ruby-like syntax sugar with the following shortcuts:
+
+{% highlight coffeescript %}
+String::strip = -> if String::trim? then @trim() else @replace /^\s+|\s+$/g, ""
+String::lstrip = -> @replace /^\s+/g, ""
+String::rstrip = -> @replace /\s+$/g, ""
+
+"  padded string  ".strip()
+# => 'padded string'
+"  padded string  ".lstrip()
+# => 'padded string  '
+"  padded string  ".rstrip()
+# => '  padded string'
+{% endhighlight %}
+
+For an interesting discussion and benchmarks of JavaScript `trim` performance, see [this blog post](http://blog.stevenlevithan.com/archives/faster-trim-javascript) by Steve Levithan.

chapters/strings/uppercasing-a-string.md

@@ -0,0 +1,45 @@
+---
+layout: recipe
+title: Uppercasing a String
+chapter: Strings
+---
+## Problem
+
+You want to uppercase a string.
+
+## Solution
+
+Use JavaScript's String toUpperCase() method:
+
+{% highlight coffeescript %}
+"one two three".toUpperCase()
+# => 'ONE TWO THREE'
+{% endhighlight %}
+
+## Discussion
+
+`toUpperCase()` is a standard JavaScript method. Don't forget the parentheses.
+
+### Syntax Sugar
+
+You can add some Ruby-like syntax sugar with the following shortcut:
+
+{% highlight coffeescript %}
+String::upcase = -> @toUpperCase()
+"one two three".upcase()
+# => 'ONE TWO THREE'
+{% endhighlight %}
+
+The snippet above demonstrates a few features of CoffeeScript:
+
+* The double-colon `::` is shorthand for saying `.prototype.`
+* The "at" sign `@` is shorthand for saying `this.`
+
+The code above compiles in to the following JavaScript:
+
+{% highlight javascript %}
+String.prototype.upcase = function() {
+  return this.toUpperCase();
+};
+"one two three".upcase();
+{% endhighlight %}

wanted-recipes.md

@@ -19,10 +19,7 @@ In the notes below, "JS" means the recipe is just a simple passthrough to an exi
 * HTML methods # JS .sup(), .sub(), .blink(), .link(url), etc. May not exist in your JS impl!
 * substr # str.substr(x,y)  === str[x..x+y-1] === str[x...x+y]
 * substring # str.substring(x,y) === str.slice(x,y)  === str[x..y-1] === str[x...y]
-* Uppercasing a string # JS toUpperCase()
-* Lowercasing a string # JS toLowerCase()
 * Replacing substrings
-* Trimming whitespace from the end of a string
 
 ## Arrays
 
@@ -36,7 +33,6 @@ evens.every even
 * Filtering arrays # [1..10.filter (x) -> x % 2 == 0 # => [ 2, 4, 6, 8, 10 ]
 * Detecting presence of matching items in an array # [1..10].some (x) -> x % 2 == 0 # => true
 * Processing an array item by item # [10..1].forEach (x) -> console.log x # => nothing;, but a countdown is displayed on the console
-* Creating a string from an array
 * Replace all duplicates of an array
 
 ## Dates and Times
@@ -91,7 +87,6 @@ foo 1, 2, 3
 * Searching for substrings # "foo bar baz".match(/ba./) # => [ 'bar', index: 4, input: 'foo bar baz' ]
 * Searching for substrings # "foo bar baz".search(/ba./) # => 4
 * Replacing substrings # "foo bar baz".replace( /ba./, 'foo') # => "foo foo baz"
-* Replace HTML tags with named HTML entities # <br/> => &lt;br/&gt;
 
 ## Networking