import type { D3SymbolName } from '../../labels';
import type { DataSeries, LegendItem, PointStyle } from './types';
export declare const get_series_symbol: (series_idx: number) => D3SymbolName;
export declare const first_point_style: (series_data: {
    point_style?: PointStyle[] | PointStyle;
} | null | undefined) => PointStyle | undefined;
export declare const extract_series_color: (series_data: DataSeries) => string;
type LegendSeries = {
    label?: string | null;
    visible?: boolean;
    legend_group?: string;
};
export declare function build_legend_items<Series extends LegendSeries>(series: readonly Series[], display_style: (series_data: Series, series_idx: number) => LegendItem[`display_style`], opts?: {
    default_label?: (series_idx: number) => string;
    label?: (series_data: Series, series_idx: number) => string | null | undefined;
}): LegendItem[];
export declare const series_symbol_swatch: (series_data: DataSeries) => {
    symbol_type: D3SymbolName;
    symbol_color: string;
};
export declare const process_prop: <T>(prop: T[] | T | undefined | null, idx: number) => T | undefined;
export {};