A chain step that references a derived evidence is now expanded at compile
time, keeping the engine a flat edge-traversal evaluator:
- DIRECT evidence step -> renamed to its underlying relation
(member_of(user,*g){ group_read(g,doc) } where group_read = can_view
becomes step 'can_view').
- CHAIN evidence step -> its steps are spliced into the parent chain
(a sub-path flattens into the linear source->...->object traversal).
- Any other evidence type (defeasible/logical/comparator) as a step is a
compile-time error: it is a condition, not an edge traversal.
- Cycles and self-references through chain steps are compile-time errors
(the existing composition cycle guard now covers steps).
Rigor: oracle campaign gains a chain_step_composition construct; illegal
mutations gain a non-lowerable-chain-step case. Fixture suites updated to
retarget the self-recursive 'canRead/canAccess/...' terminals (an unsupported
recursion pattern that now fails loudly) to an any-typed 'reachable' fact,
preserving the nested-pattern parsing intent.
The legacy test files (Definition/Evidence/Expression/Fact/Integration/
Measure) predate the DSL's validation rules: reserved built-in types
(User/Account/Device/AuthSession) and the boolean/predicate-call
requirements on evidence statements. Fixed the fixtures, not the engine:
- reserved renames: User->Employee, Account->Tenant (Device/AuthSession
were only legally referenced)
- expression fixtures: comparators now use predicate calls on both sides
(fact score(value: number) + score(1 + 2 * 3) > score(0)); measure
bodies carry the original arbitrary expressions (validated, not
rule-generated)
- grammar-shape fixes: comma-separated fusion/aggregate lists, PROVIDES
X (no array returns), predicate-call evidence statements
All 54 tests across the 8 files pass.
The Evidence DSL (ADR-000) is a thin declarative layer that compiles to
engine rule types. It has zero runtime coupling to the core engine
(DSLCompiler takes an arbiter as a duck-typed argument; the only shared
code was the ip-utils helpers, now local). Extracting it into its own
package keeps the core artifact free of the DSL surface.
- @arbiter/evidence-dsl depends on @arbiter/core (config formats are the
compilation target)
- deep-path exports for the compiler, parser, generator, validation,
and built-in functions (the surface the core's DSL tests consume)
- tests moved alongside; generate-parser script + peggy devDep local
- CI: test on push, publish on v* tags
John Dvorak