From: David Allsopp <dra-news@metastack.com>
To: "'Tie Cheng'" <chengtie@gmail.com>,
"'caml-list@yquem.inria.fr'" <caml-list@yquem.inria.fr>
Subject: RE: [Caml-list] AtomMap: build a list of all the elements in a map
Date: Mon, 21 Feb 2011 12:44:31 +0000 [thread overview]
Message-ID: <E51C5B015DBD1348A1D85763337FB6D9490F09C9@Remus.metastack.local> (raw)
In-Reply-To: <AANLkTingFB4Jfem__Zjoq6DS-WYiYdzHUz6sYgGcb8r5@mail.gmail.com>
Tie Cheng wrote:
> I have posted a question on Caml-beginners, but have not got
> response so far... guess maybe you could here... I have defined
> "type AT = A AtomMap.t". Do you know how to build a function
> "f: AT -> (atom * A) list" which returns a list of all the
> elements in a map?
> I am trying to combine AtomMap.fold, AtomMap.Iter
> (in this manual http://cristal.inria.fr/~fpottier/alphaCaml/alphaCaml.pdf)
> to do so... But it seems that unlike List.folder_left, AtomMap.fold
> does not accept list as argument: val fold : (key -> 'a -> 'b -> 'b)
> -> 'a t -> 'b -> 'b, there it is not convenient to build a list
> progressively here...
I don't see how that function signature differs from what you expect so sorry if that's because I don't know anything about alphaCaml!
What's wrong with:
fold (fun key value acc -> (key, value)::acc)) atomMap []
The signature for [fold] is simply like the signature for List.fold_right rather than List.fold_left.
David
next prev parent reply other threads:[~2011-02-21 12:53 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-21 12:40 Tie Cheng
2011-02-21 12:44 ` David Allsopp [this message]
2011-02-21 13:05 ` Raphael Proust
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