LDC-E1351 — Automaton member name taken twice

What it means

States, transitions, and regions share one package-wide name table: a case names a member by its bare name, so two members under one name would resolve to neither. When two procedures declare the same member name, the compiler stops at the second declaration and lists both owners.

The repair is to differentiate: prefix the names per procedure, or rename one side. Unique names resolve exactly as written.

Example

Arxo Law

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

entity Tenant;
procedure A(t: Tenant) {
    state Open initial;
    state Closed terminal;
}
procedure B(t: Tenant) {
    state Open initial;
    state Shut terminal;
}

Fix

Arxo Law

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

entity Tenant;
procedure A(t: Tenant) {
    state Open initial;
    state Closed terminal;
}
procedure B(t: Tenant) {
    state Dawn initial;
    state Shut terminal;
}

Engine message

The engine reports this in its own wording:

Output

example.law:11:11: error LDC-E1351: automaton member name "Open" is declared 2 times (state `A/Open`, state `B/Open`) — a state, transition or region name is unique within a package (§160.2, errata E-0149): the program and the §168 case name a member by a bare name, and one name on two members would resolve to neither. The resolution is to differentiate names in the program itself (e.g. with a procedure prefix)

Related

• Procedures — states, transitions, and how a procedure runs.
• LDC-E1201 — the companion collision for declared names.