PureScript FFI函数没有返回值,只有副作用

渲染器.purs:

module Renderer where
import Prelude
import Effect (Effect)

foreign import renderMd :: String -> Effect Unit

渲染器.js:

var md = require('markdown-it')();
exports.renderMd = function(str) {
  document.body.append( md.render(str) );
}

import React.Basic.DOM as R
import React.Basic.DOM.Events (targetValue)
import React.Basic.Events as Events

R.textarea
  { onChange: Events.handler targetValue $ maybe (pure unit) renderMd
  }

编译得很好,但给出:

Uncaught TypeError: cb(...) is not a function

在purescript-react-basic的定义中 handler ,编译时间:

var handler = function (v) {
    return function (cb) {
        return function ($22) {
            return cb(v($22))();
        };
    };
};