[erlang-questions] Maps branch and disclaimers

Chris King <>
Wed Oct 30 17:13:16 CET 2013


On Wed, 30 Oct 2013 11:48:33 -0400, Robert Virding  
<> wrote:

> I need this ability to step through a map/dict/whatever in an  
> application I am working on (luerl). Dict does not provide this type of  
> functionality. It would be easy to hack into an orddict but I don't want  
> to use lists. Gb_trees provides an iterators but they are quite limited  
> in that they only allow you to step through the whole tree from  
> beginning to end; you can't jump in in the middle. Which I need to be  
> able to do.

That answers why you need iteration through a homogeneous map-like data  
structure.  I get that.

But why does that need to be joined with syntax support?

(My thesis is that syntax support and iteration apply to two distinct use  
cases of key-value maps, and that they should be kept separate rather than  
piggybacking on each other, in order to permit better optimization, to  
decouple development, and to simplify typechecking.)


More information about the erlang-questions mailing list