LDC-E1304 — Relation key names an undeclared parameter

What it means

A relation key lists the parameters that identify each row: every name in the key must be a parameter the relation itself declares. A key that names something the parameter list never introduced points at nothing, so the compiler stops at the unknown name.

The repair is a spelling check against the parameter list: fix the typo, declare the missing parameter, or drop the name from the key. The key keeps only what the relation declares.

Example

Arxo Law

language "law.core" version "0.2";
package demo.diagnostics version "0.1.0";
namespace "urn:law:demo:diagnostics";

relation p(x: Text) kind institutional {
    key(y);
}

Fix

Arxo Law

language "law.core" version "0.2";
package demo.diagnostics version "0.1.0";
namespace "urn:law:demo:diagnostics";

relation p(x: Text) kind institutional {
    key(x);
}

Engine message

The engine reports this in its own wording:

Output

example.law:6:9: error LDC-E1304: key(y): parameter is not declared in relation "p" (§45.1)

Related

• Vocabulary — how names are declared and which positions take them.