LDC-Q2005 — The expression names a variable the query never bound

What it means

Inside a filter or a return list, every name must come from somewhere: a source introduced at the head of the query. A name with no source is not an empty value and not a typo the engine will guess past — the expression cannot be evaluated for any row, so the query stops at the first row that reaches it.

Bind the name in a source, or replace it with the source variable the expression was meant to read.

Example

Both queries below run against this package:

Arxo Law

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

entity Applicant;
relation resident(a: Applicant) kind institutional;
relation permit_eligible(a: Applicant) kind institutional;

rule PermitEligibility strict {
    for a: Applicant;
    when resident(a);
    then permit_eligible(a);
}

The filter reads a name no source introduces:

LawQL

from r in rules where zzz == 1 select r

Fix

LawQL

from r in rules select r

Engine message

The engine reports this in its own wording:

Output

LDC-Q2005: variable 'zzz' is not bound.

Related

• Questions to the engine — how sources bind names.
• LDC-Q2007 — when the name exists but the field does not.