[m-rev.] for review: better synonyms for digraph.m's tsort and atsort

[Julien Fischer]

On Thu, 16 Mar 2017, Zoltan Somogyi wrote:

> As we discussed a few days ago.
>
> For review by anyone.
>
> Add from_to and to_from versions of tsort and atsort.

...

> diff --git a/NEWS b/NEWS
> index 8bdd8b2..d6f755d 100644
> --- a/NEWS
> +++ b/NEWS

...

> @@ -435,6 +435,13 @@ Changes to the Mercury standard library:
>    - maybe_pred/3
>    - maybe_func/2
> 
> +* We have added the following predicates and functions to the digraph module:
> +
> +  - return_vertices_in_from_to_order
> +  - return_vertices_in_to_from_order
> +  - return_sccs_in_from_to_order
> +  - return_sccs_in_to_from_order

The usual convention in the NEWS file is to give the arity as well.

The rest of the diff is fine.

Julien.