Function createEngine

scripts/fungrim/load.ts:133–153

(
  declarations: Declarations,
  options?: { compat?: boolean }
)

 * require `set` operands (every Fungrim domain is mathematically a set).
 * Rewrite `collection` -> `set` in shell signatures. (`set` is a subtype of
 * `collection`, so Element/indexing-set usages keep working.)
 */
function setify(signature: string): string {
  return signature.replace(/\bcollection\b/g, 'set');
}

/**
 * Names from the declarations table that are NOT engine built-ins — the
 * true shells. The table is generated when the translator runs; heads
 * promoted to engine built-ins since then (e.g. the Tier-2 special-function
 * kernels: EllipticK/E, AGM, Hypergeometric2F1/1F1, JacobiTheta,
 * DedekindEta) must not be re-declared, or the signature-only shell would
 * shadow the built-in and hide its numeric evaluator.
 */
export function shellOnlyNames(declarations: Declarations): Set<string> {
  const probe = new ComputeEngine();
  const out = new Set<string>();
  for (const name of Object.keys(declarations.declarations))
    if (probe.lookupDefinition(name) === undefined) out.add(name);
  return out;
}

/**
 * Create a ComputeEngine with every shell declared in a dedicated child