2010/10/12 Mathias Kende <mathias@kende.fr>

> To represent "abstract" graphs (those were the
> equality for the nodes type is not used to check if two nodes of a graph
> are the same), the library uses an internal counter. This counter must
> be serialised along with the graphs and then it must be updated
> correctly when graphs are unserialised to avoid creating a node with the
> same identifier than o node in the unserialised graphs.
>
> This is explained in the FAQ :
> http://ocamlgraph.lri.fr/FAQ
>

I didn't remember myself that the OcamlGraph FAQ contains a section about
that ;-).

But I bielieve that the FAQ got it wrong in case multiple graphs are
> unserialised, or nodes are created before the unserialisation of other
> nodes. In these situation using concrete graphs, which do not suffer
> from this problem, is certainly easier (as advertised by the manual).
> And I manually add identifiers to the nodes if I need many nodes with
> the same label.
>

Of course you're right (see also my own answer to Alexey) : I will update
the OcamlGraph FAQ accordingly.

Thanks,
Julien