Function evaluateCondition

packages/graph/src/Steps.ts:1019–1146

(
  path: TraversalPath<any, any, any>,
  condition: Condition,
  context?: QueryContext,
)

  | IsLabeledCondition;

function evaluateCondition(
  path: TraversalPath<any, any, any>,
  condition: Condition,
  context?: QueryContext,
): boolean {
  switch (condition[0]) {
    case "and": {
      for (let i = 1; i < condition.length; i++) {
        if (!evaluateCondition(path, condition[i] as Condition, context)) {
          return false;
        }
      }
      return true;
    }
    case "or": {
      for (let i = 1; i < condition.length; i++) {
        if (evaluateCondition(path, condition[i] as Condition, context)) {
          return true;
        }
      }
      return false;
    }
    case "xor": {
      // XOR: exactly one of the conditions must be true
      let trueCount = 0;
      for (let i = 1; i < condition.length; i++) {
        if (evaluateCondition(path, condition[i] as Condition, context)) {
          trueCount++;
        }
      }
      return trueCount === 1;
    }
    case "not": {
      return !evaluateCondition(path, condition[1] as Condition, context);
    }
    case "exists": {
      const key = condition[1]!;
      const element = path.value;
      if (!(element instanceof Vertex || element instanceof Edge)) {
        return false;
      }
      return key === "@id"
        ? element.id !== undefined
        : key === "@label"
          ? element.label !== undefined
          : element.get(key) !== undefined;
    }
    case "isNull": {
      const key = condition[1]!;
      const element = path.value;
      if (!(element instanceof Vertex || element instanceof Edge)) {
        return true;
      }
      const value =
        key === "@id" ? element.id : key === "@label" ? element.label : element.get(key);
      return value === undefined || value === null;
    }
    case "isNotNull": {