条件

将给定的（一元或二元）条件应用于步骤，并返回表示布尔结果的步骤。

用法

// value === null?
function condition(
  operation: "null",
  $value: ExecutableStep,
): ExecutableStep<boolean>;

// value !== null?
function condition(
  operation: "not null",
  $value: ExecutableStep,
): ExecutableStep<boolean>;

// value != null
function condition(
  operation: "exists",
  $value: ExecutableStep,
): ExecutableStep<boolean>;

// value == null
function condition(
  operation: "not exists",
  $value: ExecutableStep,
): ExecutableStep<boolean>;

// a === b
function condition(
  operation: "===",
  $a: ExecutableStep,
  $b: ExecutableStep,
): ExecutableStep<boolean>;

// a !== b
function condition(
  operation: "!==",
  $a: ExecutableStep,
  $b: ExecutableStep,
): ExecutableStep<boolean>;