component.mpn

What it is ¶

component.mpn(ref_des, mpn) yields one row per component that resolves to a manufacturer part number: the design-side part identity. The mpn value is the exact orderable part (“BSS138”, “LM1117MPX-3.3”), not a class or a generic value. A component with no resolved part number produces no row.

For hardware engineers ¶

This is the BOM answer for a reference designator: which physical part R7 or U3 will be built as. Two schematics can be electrically identical and place different parts; only the part number distinguishes them, and it is what the datasheet checks join against. You query it to list what a design actually orders, or to find the components a datasheet-backed rule can reach (a component with no part number has no datasheet to check against).

For software engineers ¶

The part number is the lockfile entry (see ANALOGY.md): component-on-net and pin describe the graph structure, component.mpn binds a node to a concrete pinned artifact (lodash@4.17.21). Rows are 1:1 with components that carry a resolved part number, so it is a partial projection over Components() (unresolved components are simply absent). It is the design half of the datasheet join key; the datasheet half is param(mpn, symbol, max), keyed by the same string.

Go projector ¶

componentMPNFacts in check/facts.go walks Model.Components() and emits a row for each component where Model.ComponentMPN(ref) is non-empty. ComponentMPN returns the BomLine part number when a BOM covers the ref-des, else the component’s MPN/mpn attribute, else “”. It never parses the free-text Value field, so the identity is only ever what the design declared. Each reader normalizes its own vendor part-number property into the canonical MPN attribute (OrCAD/Allegro carry it under Manufacturer_PN, which the EDIF reader maps to MPN), so this one relation reads uniformly across formats.

One row per component with a resolved part number. Empty result: the model was built without a params tier. The MPN index is populated only by NewModelWithParams, so the relation is empty unless agni was run with --params (an empty params directory is enough to build the index).

Datalog ¶

Every component and its part number:

component.mpn(?r, ?m) => ?r

Join to the datasheet parameters seeded for that part (the components a datasheet rule can reach):

component.mpn(?r, ?m), param(?m, ?sym, ?max) => ?r