如何使用variant选项在rescript中键入函数参数？

Question

我想做以下几件事。但是我似乎不能使用其中一个变量选项来键入函数参数。在rescript中实现这一点的正确方法是什么？

Here is a playground

  type subject = Math | History

  type person =
    | Teacher({firstName: string, subject: subject})
    | Student({firstName: string})
  
  let hasSameNameThanTeacher = (
    ~teacher: Teacher, // syntax error here
    ~student: Person,
  ) => {
    teacher.firstName == student.firstName
  }

Answer 1

Teacher和Student本身不是类型，而是构造person类型的值的构造函数。如果你想让它们有不同的类型，你必须让它显式：

module University = {
  type subject = Math | History

  type teacher = {firstName: string, subject: subject}
  type student = {firstName: string}
  type person =
    | Teacher(teacher)
    | Student(student)
  
  let hasSameNameThanTeacher = (
    ~teacher: teacher,
    ~student: student,
  ) => {
    teacher.firstName == student.firstName
  }
}