A failed mapper expression fails the node and names the port
The rule
Normative: this is the rule
When the expression for a mapper output fails, the node fails, the failure names the output port whose expression failed, and no partial output map is produced.
Rule identifiers are permanent and are never renumbered. Each implementation publishes its own standing against these rules; this specification does not.spec 1.0-draft · LANG-21 · changed in spec 1.0