import GridData from '../grid.js';
import Instruction from '../instruction.js';
import Symbol from '../symbols/symbol.js';
export interface SymbolDisplayHandler {
    /**
     * Controls whether a symbol should be visible in the grid.
     *
     * @param grid The grid that is being displayed.
     * @param solution The solution grid, if it is available.
     * @param symbol The symbol that is being displayed.
     * @param editing Whether the grid is being edited.
     * @returns True if the symbol should be displayed, false otherwise. The symbol will not be displayed if any handler returns false.
     */
    onSymbolDisplay(grid: GridData, solution: GridData | null, symbol: Symbol, editing: boolean): boolean;
}
export declare function handlesSymbolDisplay<T extends Instruction>(val: T): val is T & SymbolDisplayHandler;