Kanit Wongsuphasawat

There are some conflicts, possibly because encoding.ts and its test file have been splitted.

@yhoonkim Can you rebase this when you have time?

Basically, a `SpecQuery` is provided as `spec` property of a `Query`. Data can be provided inline via `spec.data.values`. If the data is provided inline, - [x] make schema optional in...

We can approach this issue like this: - [ ] Add `violatePropertyPrecedenceConstraint(propertyPrecedence: Property[])` method in `property.ts` to check both conditions above and return null if it's okay and return a...

Having origin twice causes alternative encodings to re-use both row and column. 

Let's punt on this until we found that performance becomes an issue.

@RileyChang Basically, if a particular timeUnit gives cardinality `distinct` of 1, then it is a bad timeUnit to enumerate (because you don't see variation of `timeUnit` at all!) so we...

- [ ] From #109, since `schema` can be optional, check if schema is defined, if not, return true. (Because we can't know if the spec violates the constraint, so...

Note that this is quite important to make the schema legible. (It will reduce number of stacks in JSON schema validation error.)

Well, in Vega-Lite use case, we need the intermediate ones because RealA is generic and A is an alias for a specific form of generic. Thus, we can't really avoid...