textWritingModeAsExpression

The property allows control over a symbol's orientation. Note that the property values act as a hint, so that a symbol whose language doesn’t support the provided orientation will be laid out in its natural orientation. Example: English point symbol will be rendered horizontally even if array value contains single 'vertical' enum value. For symbol with point placement, the order of elements in an array define priority order for the placement of an orientation variant. For symbol with line placement, the default text writing mode is either 'horizontal', 'vertical' or 'vertical', 'horizontal', the order doesn't affect the placement.

This is an Expression representation of "text-writing-mode".