Comments on This is me: Erlang Binary Map

"Really, what is the point of using Erlang if we d...

2008-11-13T21:51:00.000+10:00

"Really, what is the point of using Erlang if we don't spawn a few hundred processes for every trivial piece of code?"

lol

Herrmann: I have been considering Haskell for som...

2007-06-30T20:23:00.000+10:00

Herrmann: I have been considering Haskell for some time now, but I get the feeling that the Erlang VM and OTP modules currently support more features that I [think I] need.

I am going to have to remember the concept of list fusions for a later project of mine (one in a list of many). I hope I will be able to incorporate the idea because it is definitely useful to have the compiler do it automatically for the developer.

Anonymous: Thank you for confirming my suspicion. A binary counterpart to list comprehensions is way too useful to be missing from the language. Time to update my code!

In recent erlangs there is an undocumented binary ...

2007-06-30T06:48:00.000+10:00

In recent erlangs there is an undocumented binary comprehension mechanism.

-module(blb).
-compile([binary_comprehension,export_all]).

double() ->
[2 * N || <<N:16>> <= <<1,2,3,4>>].

this evaluates to [516,1544] like one of your examples. You must remember to compile with the binary_comprehension option to enable this syntax. See the whitepaper for more information...

There's a technique called List Fusion which helps...

2007-06-30T02:46:00.000+10:00

There's a technique called List Fusion which helps avoiding the problem with intermediate lists you described. In Haskell:

http://www.haskell.org/ghc/docs/latest/html/users_guide/rewrite-rules.html#id3159016

'If a "good consumer" consumes an intermediate list constructed by a "good producer", the intermediate list should be eliminated entirely.'