Re: Useful failures for set inequality in plunit

On Sat, 2013-08-10 at 17:21 -0700, Ross Boylan wrote:
> 
> 2) It would be more useful to have the shorter output of values
> expected
> and not found, and then values found but not expected.  The test could
> code that, but is there a more elegant approach?
> 
> I suppose I could compute the asymmetric differences in the code and
> then make the true option for the test work in terms of those
> differences.  But it still seems a bit manual. 
Here's what that looks like:
<code>
% return asymmetric set differences
% inputs are an expected list
% and an actual ordered set
% real_vs_ideal(+Actual, +Expected, -real_ideal(JustActual,
JustExpected))
real_vs_ideal(Actual, Expected, real_ideal(JustActual, JustExpected)) :-
	is_ordset(Actual),
	list_to_ord_set(Expected, ExpectedSet),
	ord_subtract(Actual, ExpectedSet, JustActual),
	ord_subtract(ExpectedSet, Actual, JustExpected).

test(content1, [true(X == real_ideal([], []))]) :-
	content_ancestors(path(['ossecond1', 'archive']), when(date(2011, 6,
1), seq(10)), Graph),
	graph_ordered_nodes(Graph, ActualNodes),
	% It's not clear if /home/ross should be here, but algorithm currently
includes it.
	% xda1 is also marginal
	real_vs_ideal(ActualNodes,
		      [xdb1, xda2, xda1, path(['osfirst1', 'home']), path(['osfirst1',
'home', 'ross']),
		       path(['osfirst1', 'mnt']), path(['osfirst1', 'sillyfile']),
path(['ossecond1', 'archive'])],
		      X).
</code>

<output>
ERROR: /home/ross/disks/rulesTest.plt:69:
	test content1: wrong answer (compared using ==)
ERROR:     Expected: real_ideal([],[])
ERROR:     Got:      real_ideal([path([osfirst1,oldhome])],[xda1])
</output>