Function convertLabelExpression

packages/graph/src/astToSteps.ts:1983–2015

* Convert a LabelExpression AST node to a StepCondition. * Supports: LabelName, LabelOr, LabelAnd, LabelNot, LabelWildcard

(expr: LabelExpression)

 * Supports: LabelName, LabelOr, LabelAnd, LabelNot, LabelWildcard
 */
function convertLabelExpression(expr: LabelExpression): StepCondition {
  switch (expr.type) {
    case "LabelName":
      return ["=", "@label", expr.name] as StepCondition;

    case "LabelOr":
      return [
        "or",
        convertLabelExpression(expr.left),
        convertLabelExpression(expr.right),
      ] as StepCondition;

    case "LabelAnd":
      return [
        "and",
        convertLabelExpression(expr.left),
        convertLabelExpression(expr.right),
      ] as StepCondition;

    case "LabelNot":
      return ["not", convertLabelExpression(expr.expression)] as StepCondition;

    case "LabelWildcard":
      // Wildcard matches any label - represented as "has a label" check
      return ["labelWildcard"] as StepCondition;

    default: {
      // Exhaustive check
      const _exhaustive: never = expr;
      throw new Error(`Unknown label expression type: ${(_exhaustive as any).type}`);
    }
  }
}

/**
 * Create a label condition from either simple labels or a label expression.