Function isRuleStep

src/compute-engine/boxed-expression/rules.ts:1506–1508

(x: unknown)

  // order (and thus the dedup behavior) of the linear scan. With
  // `recursive`, head dispatch is unsound — keep the linear scan.
  const index = options?.recursive
    ? undefined
    : getRuleIndex(rules.rules, options?.useVariations === true);

  if (index === undefined) for (const rule of rules.rules) collect(rule);
  else for (const { rule } of candidateRules(index, expr, -1)) collect(rule);