[Haskell-cafe] Re: What do _you_ want to see in FGL?

[Henning Thielemann]

Heinrich Apfelmus schrieb:

> Ivan Miljenovic wrote:

>> I'm not sure I understand what you're saying here: first you said you
>> wanted to be able to specify a vertex type, now you're saying that you
>> don't want to know what the vertex type even is (except that it's some
>> abstract Node type)?  Whilst this would make graph usage safer/more
>> robust, this seems to contradict your earlier arguments...
> 
> I'd be happy with either one. :) In both cases, I want to specify a
> custom vertex type.
> 
> I can either do that directly if the library permits, though I think the
> solution with associated types is too cumbersome to be useful for my
> make  example.
> 
> Or I get an abstract  Node  type and the library provides just the right
> functions that make it easy to manage a custom vertex type myself. I had
> hoped that the  Data.Graph.Inductive.NodeMap  module provides this,
> which it doesn't.
> 
> In other words, the abstractness of  Node  forces the library to provide
> a well-designed set of functions to work with them, and that's what I'm
> after. In my  make  example, I spent the most time thinking about how to
> manage the  Int  nodes, finally settling with  Data.Map.findIndex , and
> I prefer the library to think about that for me.

Full acknowledge!