[rb-general] BUILD_PATH_PREFIX_MAP format spec, draft #1

[Daniel Shahaf]

Ximin Luo wrote on Sat, Jan 21, 2017 at 13:50:00 +0000:
>   - Decoders in most programming languages decode to a { key -> value list }
>     rather than a list of pairs as we require, and there is no simple way to
>     massage this into a list of pairs that still preserves ordering.

Preserving ordering raises an interesting question: what do we do when
two key-value pairs have the same key?  Do we leave that undefined, or
former wins, or latter wins…?

That's entirely independent of which encoding is chosen.