v4.4.0

[jheer]

Changes:

• Add signal init expression support.
• Add operator initonly parameterization.
• Add exported format reader hash for other projects to extend.
• Fix signal lookup for compare. (Transform Window sort order does not accept anonymous signal expressions vega#1452)
• Fix data format schema.
• Clean up stack transform internals.
• Update dependencies.

The updated d3-array 2.0 dependency uses ES6 features. Do not directly use Vega v4.4.0 or later if you require strict ES5 compliance. As Vega already requires polyfills for Promise, Symbol, and fetch support, this does not constitute a breaking change.

[domoritz]

I think we should drop ES5 support anyway. See vega/vega-lite#4283

[jheer]

I agree, though wanted this to coincide with a major version release. Unfortunately, the change log and release notes for d3-array 2.0 did not mention this aspect, and so I did not catch it until after updating all the repos and then discovering an uglify failure in vega-lib (we now use terser).