Question

问题是Nim语言的具体情况。我正在寻找一种标准，以一种类型安全的方式将整数/字符串转换为枚举。使用ord（）和$（）可以很容易地从enum转换为整数/字符串，但是我无法轻松地进行相反的转换。

假设我有以下类型声明

ProductGroup {.pure.} = enum
  Food = (3, "Food and drinks"),
  kitchen = (9, "Kitchen appliance and cutlery"),
  Bedroom = (15, "Pillows, Beddings and stuff"),
  Bathroom = (17, "Shower gels and shampoo")

我正在寻找一种标准的方法：

const
   product1 : seq[ProductGroup] = xxSomethingxx(@[3, 3, 17, 9, 15])

   product2 : seq[ProductGroup] = zzSomethingzz(@["Kitchen appliance and cutlery", "Kitchen appliance and cutlery", "Shower gels and shampoo"]) 

   product3 : seq[ProductGroup] = xxSomethingxx(@[2]) ## compilation error "2 does not convert into ProductGroup"

Answer 1

从int到enum的类型转换，从string到enum的strutils.parseEnum：

import strutils, sequtils

type ProductGroup {.pure.} = enum
  Food = (3, "Food and drinks"),
  kitchen = (9, "Kitchen appliance and cutlery"),
  Bedroom = (15, "Pillows, Beddings and stuff"),
  Bathroom = (17, "Shower gels and shampoo")

const
  product1 = [3, 3, 17, 9, 15].mapIt(ProductGroup(it))
  product2 = ["Kitchen appliance and cutlery", "Kitchen appliance and cutlery", "Shower gels and shampoo"].mapIt(parseEnum[ProductGroup](it))
  product3 = ProductGroup(2)

Nim：将整数/字符串转换为枚举的标准方法

1 个答案: