Hacker News Reader

Comment by lozenge | Hacker News Reader

Agreed. Erlang is another language with single assignment, i.e. every variable assignment target must have a new name. It's incredibly easy to see what calculations and conditions affect the final outcome.

View on HN

How do you do a for loop in Erlang or something that sums up a value ?

You don't usually write for loops in Erlang, as a functional language loops are better expressed as recursive functions.

Here is an example of using a recursive function in Erlang to sum up a factorial.

  fac(1) ->
      1;
  fac(N) ->
      N * fac(N - 1).

Does Erlang handle the stack better? In most languages this would blow up if N got big enough.

Yes. Erlang has tail recursion which helps prevent that http://learnyousomeerlang.com/recursion

As the article notes, what Erlang has is Last Call Optimization, this is significantly more general than tail recursion optimization.

In addition to recursion, you can use `foldl` and `foldr` (or similar functional methods)

http://erlang.org/doc/man/lists.html

Reply on news.ycombinator.com