/**
 * The object form of a `markdown` beat: an optional frame (`header` / `sidebar-left`) around
 * exactly one main (`content` / `row-2` / `2x2`).
 *
 * Every slot is `string | string[]`, and the renderer joins an array with "\n", so the two
 * forms render identically — which is why editing a slot as text is safe as long as the form
 * it was authored in is written back.
 */
export type MarkdownSlot = string | string[];
/** The mains, in the order the editor offers them. Exactly one is present on a valid layout. */
export declare const MAIN_KINDS: readonly ["content", "row-2", "2x2"];
export type MainKind = (typeof MAIN_KINDS)[number];
/** How many slots each main carries. */
export declare const SLOT_COUNT: Record<MainKind, number>;
/** What each slot is called, from the schema's own comments on the tuples. */
export declare const SLOT_LABELS: Record<MainKind, string[]>;
export declare const FRAME_KEYS: readonly ["header", "sidebar-left"];
export type FrameKey = (typeof FRAME_KEYS)[number];
/** The layout form, as opposed to a plain string or array of lines. Carrying a main is what identifies it. */
export declare const isMarkdownLayout: (value: unknown) => value is Record<string, unknown>;
/** The main this layout carries. A malformed one with several resolves in MAIN_KINDS order. */
export declare const mainKindOf: (layout: Record<string, unknown>) => MainKind;
/** Every slot of the main, padded to the count the main declares. */
export declare const slotsOf: (layout: Record<string, unknown>) => unknown[];
/** A slot as one block of text — the same join the renderer applies to an array. */
export declare const slotText: (slot: unknown) => string;
/** Text written back in the form the slot already had, so an authored array stays an array. */
export declare const writeSlot: (current: unknown, text: string) => MarkdownSlot;
export declare const setSlot: (layout: Record<string, unknown>, index: number, text: string) => Record<string, unknown>;
/** An empty frame field is absent rather than empty: both are optional in the schema. */
export declare const setFrame: (layout: Record<string, unknown>, key: FrameKey, text: string) => Record<string, unknown>;
/**
 * The same layout under a different main, carrying the text across.
 *
 * Widening pads with empty slots; narrowing to `content` joins what there was, since dropping
 * the text of a slot that no longer exists would lose the author's writing silently.
 */
export declare const switchMain: (layout: Record<string, unknown>, kind: MainKind) => Record<string, unknown>;
/** The string form as a layout. Always safe: the text becomes the one slot `content` holds. */
export declare const toLayout: (markdown: unknown) => Record<string, unknown>;
/**
 * Whether going back to the string form would lose nothing.
 *
 * Only a bare `content` qualifies — a frame or a multi-slot main has nowhere to go in a
 * string, so the editor does not offer the conversion rather than performing it quietly.
 */
export declare const isLosslessToString: (layout: Record<string, unknown>) => boolean;