Function mountExpressionEditor

mountExpressionEditor(
    parent: HTMLElement,
    doc: string,
    options: ExpressionEditorOptions,
): MountedExpressionEditor
Create and mount a CodeMirror editor for a SafeExpression, with grammar-aware syntax highlighting and helper/identifier autocomplete.

We construct the CodeMirror EditorView ourselves (rather than reusing Foundry's <code-mirror> element, which paints blank inside a DialogV2 popup) so we can force a re-measure via focus() once the dialog is visible.
Parameters
- parent: HTMLElement
  The container element to mount the editor into.
- doc: string
  The initial expression text.
- options: ExpressionEditorOptions
  Change handler and autocomplete context (see ExpressionEditorOptions).
Returns MountedExpressionEditor
A handle to read the value, focus/measure, and destroy the editor.
- Defined in src/apps/foundry/expression-codemirror.ts:208