Erlang: What the Cool Kids Are Doing

http://www.sdtimes.com/article/column-20071015-01.html

by iamelgringo • 19 years ago

18 12 19 years ago

davidw2• 19 years ago

I thought the cool kids had already moved on to Scala...

bilbo0s• 19 years ago

That's the interesting thing isn't it. With the Scala platform around people have very little incentive to go in and make the improvements to Erlang that would help it to become more mainstream. Particularly on the web.

For instance, what follows is the code to the Scala address book example:

object addressbook {

  case class Person(name: String, age: Int)

  /** An AddressBook takes a variable number of arguments
   *  which are accessed as a Sequence
   */
  class AddressBook(a: Person*) {
    private val people: List[Person] = a.toList

    /** Serialize to XHTML. Scala supports XML literals
     *  which may contain Scala expressions between braces, 
     *  which are replaced by their evaluation
     */
    def toXHTML =
      <table cellpadding="2" cellspacing="0">
        <tr>
          <th>Last Name</th>
          <th>First Name</th>
        </tr>
        { for (val p <- people) yield
            <tr>
              <td> { p.name } </td>
              <td> { p.age.toString() } </td>
            </tr> 
        }
      </table>;
  }

  /** We introduce CSS using raw strings (between triple
   *  quotes). Raw strings may contain newlines and special 
   *  characters (like \) are not interpreted.
   */
  val header =
    <head>
      <title>
        { "My Address Book" }
      </title>
      <style type="text/css"> {
     """table { border-right: 1px solid #cccccc; }
        th { background-color: #cccccc; }
        td { border-left: 1px solid #acacac; }
        td { border-bottom: 1px solid #acacac;"""}
      </style>
    </head>;

  val people = new AddressBook(
    Person("Tom", 20),
    Person("Bob", 22),
    Person("James", 19));

  val page =
    <html>
      { header }
      <body>
       { people.toXHTML }
      </body>
    </html>;

  def main(args: Array[String]) {
    println(page)
  }

}

This is so much less scary to people than the Erlang equivalent. EQUALLY complicated, just less scary! So if there are kids out there looking at implementing something new really fast, they will be drawn to Scala.

Remember PERL, it was lightning fast . . . and really scary. Java was less scary. PHP was friendlier still. And, I suspect, the frameworks built using Scala will be downright promiscuous.

It's too bad, I'm an old fart, 36, but I like Erlang.

Maybe the kids will let their religion get the best of them. They are really anti-Java, and Scala is built on Java.

Of course, they love JRuby.

Quel dommage.

rontr• 19 years ago

The cool kids won't move on to Scala for a number of reasons, the primary of which is that Scala's actors are not as powerful as Erlang processes.

See Virding's First Rule of Programming (http://www.nabble.com/Erlang-concurrency-to14747956.html):

"Any sufficiently complicated concurrent program in another language contains an ad hoc informally-specified bug-ridden slow implementation of half of Erlang."

davidw2• 19 years ago

> Scala's actors are not as powerful as Erlang processes.

How so? I know Erlang reasonably well, but haven't messed with Scala at all.

nootopian• 19 years ago

"You cannot change the state of a variable once it has been set" http://www.onlamp.com/pub/a/onlamp/2007/09/13/introduction-t...

Im not a cool kid.

Xichekolas• 19 years ago

It sounds weird at first to have variables that don't really vary, but it works out quite nicely.

jward• 19 years ago

It's sad. After coding in Haskell and Erlang I moved back to Python for a project and my code was just littered with extra variables. I had become so used to the functional way that varying variables just seemed so wrong and foreign.

dpapathanasiou2• 19 years ago

It's not a question of cool or not; it just seems you haven't been exposed to functional programming yet.

Here's an introduction if you've got an imperative/OO background: http://www.defmacro.org/ramblings/fp.html

Tichy2• 19 years ago

I thought LISP is functional, and it lets you change variables. So I don't think that is specific to functional programming.

Erlang: What the Cool Kids Are Doing

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