net.attr

What it is ¶

net.attr(net, key, value) yields one row per attribute a net carries, as the design file declared it. It is the twin of component.attr, and it shows a net’s attributes map on the query surface.

Common keys are external (the net may continue onto a sheet the read did not cover), global (a power symbol or global label distributes it), and power_driven (a pin asserts it as a supply).

For hardware engineers ¶

These are statements the design file makes about a net, rather than conclusions the engine draws from its name. external matters most. It marks a net whose full connectivity was not read. A rule that would otherwise report a one-pin net then reports nothing, because that defect would be an artefact of what was opened.

For software engineers ¶

Until agni 691 the query surface was asymmetric, and this relation is its net-side half. A component’s attributes have been queryable since WS3-074. A net’s reached only the SPEC language, as one boolean fact per key (net.attr.external, net.attr.global), so the same question could be asked of a part and not of a net. Rows are one per key per net, and a net with no attributes yields none.

Declared, not derived. net.role holds what the ENGINE worked out about a net from its name.

Go projector ¶

netAttrFacts in stdlib/relations/facts.go walks Model.Nets() and emits a row per entry in each net’s attributes map, exactly as componentAttrFacts does for a component.

Datalog ¶

Every attribute on a net:

net.attr(?n, ?k, ?v) => ?n, ?k, ?v

The nets that a read could not see in full, which most connectivity rules exclude:

net.attr(?n, "external", "true") => ?n