Inventory label causes error

[YagiOoda]

It looks like the formatter doesn't like adding a label per the beancount documentation: https://beancount.github.io/docs/how_inventories_work.html

For the directive below there is an error until the label is removed.

[fangpenlin]

Hi @YagiOoda,

Thanks for reporting the bug. I haven't looked into details yet, but just have glance, it appears to me more like a parser bug from

https://github.com/LaunchPlatform/beancount-parser

Maybe I didn't define the label syntax correctly in the parser. I will find a time to look into this.