This pattern matches values of type option('a)

#1

Hi all

I tried to translate the following code:

import {MDCTextField} from '@material/textfield';

const textField = new MDCTextField(document.querySelector('.mdc-text-field'));

into Reasonml:

type mdcTextFieldCl;

[@bs.new] [@bs.module "@material/textfield"] external mdcTextField : Dom.element => mdcTextFieldCl = "MDCTextField";

let textField = switch (DocumentRe.getElementById("coin-amount-input")) {
| Some(a) => mdcTextField(a)
| None => raise("Can not find the element")
};

But the compiler complains:  

  We've found a bug for you!
  /home/developer/Desktop/reasonreact/cockpit/src/Inputs/CoinAmount.re 7:1-9

  5 │
  6 │ let textField = switch (DocumentRe.getElementById("coin-amount-input"))
   {
  7 │ | Some(a) => mdcTextField(a)
  8 │ | None => raise("Can not find the element")
  9 │ };

  This pattern matches values of type
option('a)
  but a pattern was expected which matches values of type
DocumentRe.t => option(Dom.element)

ninja: build stopped: subcommand failed.
>>>> Finish compiling(exit: 1)

What am I doing wrong?

Thanks

#2

The solution is:

[@bs.new] [@bs.module "@material/textfield"] external mdcTextField : Dom.element => mdcTextFieldCl = "MDCTextField";

let coinEle = Webapi.Dom.document |> DocumentRe.getElementById("coin-amount-input");

let textField = switch (coinEle) {
| Some(a) => mdcTextField(a)
| None => raise("Can not find the element")
};

thanks