elm - 如何在 Elm 中返回元素列表

Question

我正在尝试从 ELM 中的简单数组构建元素列表。预期结果实际上只是一个元素列表，其中 1 作为第一项，2 作为第二项，依此类推。

import Html exposing (..)
import Html.Attributes exposing (class, id)
import List exposing (map)

theArray = [1,2,3,4,5,6]

createListItem item =
  li [] [ text (toString item)]

buildList collection =
  map createListItem collection

builtList = ul [] [(buildList theArray)]

main = 
  builtList

但是我在第十三行不断收到编译器错误。我尝试过将 map 元素注释为 html，但我不知道应该做什么。

The 2nd argument to function `ul` is causing a mismatch.

 *13| builtList = ul [] [(buildList theArray)]*

Function `ul` is expecting the 2nd argument to be:

    List VirtualDom.Node

But it is:

    List (List Html)

Answer 1

buildList 已返回 List Html 类型的值，因此您不需要将 (buildList theArray) 括起来。将第 13 行更改为:

builtList = ul [] (buildList theArray)