Pure Components默认在shouldComponentUpdate进行浅对比，避免props和state未改变时的重复渲染

Recompose提供了高阶函数pure用于生成Pure Components

bad

export default (props,context) => {
  // ... do expensive compute on props ...
  return <SomeComponent {...props} />
}

good

import { pure } from 'recompose';
// This won't be called when the props DONT change
export default pure((props,context) => {
  // ... do expensive compute on props ...
  return <SomeComponent someProp={props.someProp}/>
})

better

// This is better mainly because it uses no external dependencies.
import { PureComponent } from 'react';

export default class Example extends PureComponent {
  // This won't re-render when the props DONT change
  render() {
    // ... do expensive compute on props ...
    return <SomeComponent someProp={props.someProp}/>
  }
}
})