Repo API: Property value encondings

[enikao]

Possible property value encondings

Encode everything as string

• Uniform handling
• Can encode everything
• Issue: especially structured JSON values would be dumped into a string inside a JSON structure
• Diffing is easy
• We don’t expect serious performance issues from encoding boolean/integer as string
• Doesn't waste too much space

Use JSON types

• Natural representation for boolean, strings
• Issue: JSON number vs. Integer
  • If metamodel says property is of type int, but JSON contains 42.1
  • If int value is > 53 bit, JSON loses precision

=> Decision: for JSON transport, all primitive types are strings
Might be different for e.g. protobuf transport

[joswarmer]

Agreed that they should be strings, but shouldn't we say something about the format of the strings for each property type? E.g. a date property is in the ISO8601 format?

[enikao]

Agreed that they should be strings, but shouldn't we say something about the format of the strings for each property type? E.g. a date property is in the ISO8601 format?

Per #9, we only have support the default types int, boolean, string (and maybe JSON, tbd).
We had some discussion around things like date, but postponed it (see #10, #20) -- it's not required for the first version.

The closest we got was something like:

@Implementation(Java, "java.util.Date")
@Implementation(Typescript, "http://no.idea/how:this.works.in.ts")
typedef Date: JSON

meaning:

• There is a typedef called Date
• It's stored as JSON primitive type (this precedes the decision that everything is stored as string on protocol level)
• Java implementations automatically map it to java.util.Date
• Typescript implementations automatically map it to something sensible in Typescript

(This typedef might be shipped with LIonWeb standard library.)

Some thoughts on this design include:

• date/time is hugely complex
• there are sensible implementations in most languages, we don't want to re-invent the wheel and integrate nicely with host languages

[enikao]

@joswarmer Are your questions answered? Then I'd close.

[joswarmer]

Ok, I understand. You can close it.