net.test_point_count

What it is ¶

net.test_point_count(net, count) answers one row for every net in the design, with the number of test points on it. A net with none answers 0 rather than being left out. A test point is any component classified test_point, the same set that net.has_test_point reads, so a project that extends the class in its naming conventions is counted the same way. Each test point counts once per net however many of its pins connect there.

For hardware engineers ¶

A coverage table lists every net beside how many test points it carries, and the rows that read 0 matter most, because a bed-of-nails fixture or a flying probe cannot reach those nets. A count of one on a rail or a high-current net can also be thin, since a fixture often wants more than one contact there. Reading the whole table at once shows both.

For software engineers ¶

It is a grouped count with the empty groups filled in. A plain count(distinct ?tp) grouped by net gives no row for a net with nothing to count, so the uncovered nets would need a second query and a merge. This member counts inside the clause instead, with a body aggregate, ?c = count(distinct ?tp) : { ... }, reduced once for every net that entity(?n, "net") gives. A net with no test point gets a count over nothing, which is 0. Every net answers exactly once.

Datalog ¶

Every net and its test-point count, uncovered nets first:

net.test_point_count(?n, ?c) => ?n, ?c order by ?c, ?n

Nets carrying more than one test point:

net.test_point_count(?n, ?c), ?c > 1 => ?n, ?c

How it is defined ¶

net.test_point_count(n: net, c: number), a derived relation in the net module, defined in Datalog in stdlib/lib/net.dl. In a clause, a bare name is another member of the same module and a dotted name is a full path.

test_point_count(?n: net, ?c: number) :- entity(?n, "net"), ?c = count(distinct ?tp) : { component.net(?tp, ?n), component.class(?tp, "test_point") };

agni query --relations net.test_point_count prints the same definition. Adding a library member explains how the library is built.