Why

I created a JupyterLab extension which enables to use a color picker in languages other than CSS: https://github.com/krassowski/jupyterlab-color-picker

Instead of shipping a customized version of this package, I would love to depend on a new, more extensible version proposed by this changset.

Closes https://github.com/replit/Codemirror-CSS-color-picker/issues/22

What changed

No user-facing changes

• a new makeColorPicker function allows to customise the discovery of colors from the syntax tree
• the logic for parsing CSS colors from strings was decoupled from tree traversal logic and placed in three exported functions: parseCallExpression, parseColorLiteral and parseNamedColor, enabling re-use of these parsing functions
• parseColorLiteral now includes a regex check to validate that correct hex color was passed
• finally, I added a language argument to expose this information downstream.

Test plan

There should be no user-facing changes.