Unicode brackets for arrow notation #364
Description
Currently HSE doesn't parse brackets for arrow notation ((|) because of conflicts with HaRP. See #45
If that issue ever gets resolved then we also need to add support for the unicode variants added in D2012.
I don't think anyone uses HaRP but then no one has complained about HSE not support arrow notation very loudly. If anyone complains then I will probably remove HaRP support in the next release.