component.attr

What it is ¶

component.attr(ref_des, key, value) yields one row per key/value attribute on a component. It is the general-purpose read of the component’s declared properties: the part number (MPN), a declared interface (interface=CAN), a manufacturer, or any other property a reader carried through from the source. A component with no attributes produces no rows.

For hardware engineers ¶

These are the fields on a placed part beyond its connectivity: the properties an engineer or a tool wrote onto the symbol. The one that matters most for reviews is a declared interface: when a design annotates a transceiver with interface=CAN, an interface-profile check binds to that part by its declared property instead of guessing from net names. You query it to see what a part claims about itself, or to find every part carrying a given annotation.

For software engineers ¶

This is the component’s attribute map projected as triples, the way you would iterate a struct’s tag map. Rows are 1:many with a component (one per attribute), and the value is opaque text. It is the annotation channel host-binding and naming overlays read: binding by a declared interface attribute is an explicit key lookup, so it beats inferring identity from net-name conventions. An absent row means the component did not declare that key, not that the key is false.

Go projector ¶

componentAttrFacts in check/facts.go walks Model.Components() and emits one row per entry in each component’s Attributes map. It reads the map directly, so the fact base is exactly what the reader stored, no derivation. One row per attribute; empty when the source carries no component attributes.

Datalog ¶

Every part that declares an interface, and which one:

component.attr(?r, "interface", ?v) => ?v

Find the components bound to a specific interface (the host-binding lookup an interface profile uses):

component.attr(?r, "interface", "CAN") => ?r