Comments on: Erlang: An Introduction to Records

By: Anonymous

Anonymous — Mon, 09 May 2011 01:25:00 +0000

You can select prom dresses and quinceanera dresses from an incredible number of prom dress style, colours, makes and designs, so whatever type of look you are after for this all-important evening dresses, you will have no problem achieving prom pageant dresses.

By: Josef

Josef — Fri, 12 Mar 2010 09:08:44 +0000

Thanks!
The rather light green on the grey background made it very difficult to see the difference between () and {}. It would help it the contrast was increased.

By: Brainiac 5

Brainiac 5 — Fri, 08 Jan 2010 22:26:09 +0000

Thanks, very precise info just what I was looking for. A brief contrasting vs. ets, dicts and maybe even Mnesia might make for a great extension to this article.

By: vladev

vladev — Tue, 01 Dec 2009 17:38:53 +0000

Hi, great post.

You have a slight mistake thought:

"Since Erlang is side-effect free state cannot be kept globally."
What I think you meant was that Erlang is a functional language. Functional languages don't have state. Imperative do.

Erlang is not side-effect free language. Printing to the console is not a side-effect free operation and you can do it from virtually everywhere in Erlang. A side effect free language would be useless - you won't be able to communicate with anything (terminal, socket, etc.). Haskell can be thought of being a side-effect free, where side effects are controller by monads.

Regards

By: Alain O'Dea

Alain O'Dea — Thu, 19 Jun 2008 15:42:36 +0000

Good article. Thank you for the concise and clear description of Erlang’s records mechanism. It answered a few questions I had about guards,

By: Robert Virding

Robert Virding — Sun, 15 Jun 2008 20:19:55 +0000

Records were never intended to be anything else other than providing named fields for tuples. In this respect they *are* like C structs and should not be confused with associative arrays, use dict, orddict or gb_trees for that. Or ETS.

By: Jesse

Jesse — Sun, 15 Jun 2008 19:31:17 +0000

Gleb,

Good catch. And thanks for pointing to proplists, I didn’t know about them.

By: Jesse

Jesse — Sun, 15 Jun 2008 19:23:03 +0000

website,

I’m not sure if you’re a real person or a spam bot, but by “a la PHP, Ruby, or Python” I meant as a first-order construct. I’ll reword it so it’s less ambiguous.

By: website design

website design — Sun, 15 Jun 2008 17:44:32 +0000

> so creating associative arrays a la PHP, Ruby, or Python is an impossibility. … some more bloggery … > If you want to to add and remove fields on the fly, or if you don’t know what fields you’ll have until runtime, you should use [dicts](http://www.erlang.org/doc/man/dict.html) rather than records. Huh?

By: Gleb Peregud

Gleb Peregud — Sun, 15 Jun 2008 13:46:12 +0000

Sorry for double posting.

> Perhaps a subset of the first, records are also used to keep track of configurable options.

Yes, records may be used for this. But sometimes proplists are better choice, take a look at http://www.erlang.org/doc/man/proplists.html:

> Property lists are useful for representing inherited properties, such as
> options passed to a function where a user may specify options overriding
> the default settings, object properties, annotations, etc.