Vega-lite: lessThan / moreThan Filter

[kanitw]

For timeUnit, we can't just use expression. Using range with null values make spec not very readable.

So I think we better support lessThan / moreThan filter.
And perhaps, lessThanOrEqual / moreThanOrEqual.

[domoritz]

lt, lte, gt, gte, are pretty standard. At least we should call it greater, not more.

[kanitw]

What's wrong with "more"? (It's way shorter.)

lt, lte, gt, gte --> maybe they are okay, but less readable.

[domoritz]

greaterThan not moreThan is the standard name for >. If you want brevity, we can use gt which is standard in many query languages. E.g.: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-range-query.html

[kanitw]

Let's say gt, gte, lt, lte then.

[kanitw]

Will be addressed in https://github.com/vega/vega-lite/pull/3561