Support buffer/Uint8Array prefixes about subleveldown

[vweevers]

You wouldn't be able to use the full range of bytes, as two must be reserved for separator and lt logic. Limiting the prefix to ASCII characters makes that easier to enforce.

[CMCDragonkai]

The prefix separator is by default ! right? It's still possible to conflict with ! just by giving a prefix like abc!dsfgd. So why not allow raw buffers as prefixes, since you can always check if the prefix separator bytes is within the raw buffer bytes? One can use the buf.includes method to do this.

A more robust solution may use escaping applied to the prefix to always escape any occurrences of the prefix separator...

Not sure what you mean by lt logic.

[vweevers]

Sure, it's possible, at the cost of complexity. Can you explain your use case? I'm curious about the benefit of buffer prefixes, if you can't use the full range of bytes.

It's still possible to conflict with ! just by giving a prefix like abc!dsfgd

Not important for the discussion but FYI: subleveldown will throw a RangeError if you do that.

[CMCDragonkai]

I'm using subleveldown to store dynamic sub-levels. Depending on the usecase, I would prefer to use the name of the sublevel to be a raw buffer instead because sometimes I'm using the names as indexes. And the value I'm indexing on is itself a buffer. Right now it just involves converting to a string which seems unnecessary. However I guess a robust solution would require prefix-separator escaping.

[vweevers]

Wouldn't escaping hurt the ability to use it as an index?

[CMCDragonkai]

Only for the sublevel prefix/names. We're not affecting the keys. Not sure what you mean by hurting its ability to use it as an index.

[vweevers]

Can you share some code to clarify the use case?