Consider different serialisation

[AshleyYakeley]

Goals

• existing Haskell implementation
• stable, cross-platform, standardised
• no unnecessary info

Options:

• cereal (package) (current)
• ~binary (package)~ long variable-length encoding of Float and Double
• ~FlatBuffers: flatbuffers (package)~ difficult to serialise basic types
• CBOR: serialise (package): CBOR includes type data in serialisation
• ~flat (package)~: basically just one person, doesn't build with Stackage lts-20
• ~store (package)~: not cross-platform
• winery (package)

(See also #120)

[AshleyYakeley]

I used serial-inspector to compare.

[AshleyYakeley]

Cereal is more predictable, but it has an 8-byte length overhead for lists, including ByteArray, Text, and String.

Serialise has one-byte type information for all simple types. Also converts all numeric types to Integer, then stores them efficiently based on value.

Winery String serialization is inefficient (as [Char]), but Text is fine.

[AshleyYakeley]

Underlying types currently serialised via serialisation library:

• fixed-length "storable" types: Bool, Word8, Word16, Word64, Double
• Integer, Rational
• vectorish types: StrictByteString, String, Text

Note Void and () are done directly, not via serialisation library.

Maybe, [] etc. are not serialised.

[AshleyYakeley]

Looks like we're doing our own thing here.

[AshleyYakeley]

Done.