Children as callback

[pearmini]

related: https://github.com/charming-art/charming/pull/363

links:

• https://observablehq.com/d/de3177fcb5fed027
• https://observablehq.com/d/af7ef0b292ba9e27

Better because:

• consistent style with other attributes
• easy to use and implement

[Copilot]

Pull Request Overview

This PR refactors the rendering logic to support child callbacks, improving consistency with other attributes and simplifying usage.

• In src/render.js, the patch function now returns only parents and child nodes, with previous nodes being set separately.
• In src/mark.js, the patch method is refactored to update how child nodes are processed, using a consistent callback style.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/render.js	Refactored patch function signature and variable assignment for patches
src/mark.js	Refactored children callback handling and return values in patch method

Comments suppressed due to low confidence (1)

src/mark.js:124

• [nitpick] Consider reviewing the use of '.flat(Infinity)' below: if the depth of children is known, specifying the depth may improve efficiency.

newNodesChildren[i] = (isFunction(children) ? children(datum, i, data) : children)