@mui/internal-docs-infra/pipeline/parseSource/redistributeFrameFallbacks.d.mts

MUI Infra - internal documentation creation tools.

import type { ElementContent } from 'hast';
/**
 * A frame's precomputed plain-text fallback together with the inclusive
 * 1-based source line range it covers.
 *
 * `nodes` is the `frame.data.fallback` array — usually a single text node
 * whose concatenated value equals the frame's rendered plain text (with a
 * trailing newline on every line except the final line of the source).
 */
export interface FrameFallback {
  startLine: number;
  endLine: number;
  nodes: ElementContent[];
}
/**
 * A new frame's target line range (inclusive, 1-based).
 */
export interface FrameRangeBounds {
  startLine: number;
  endLine: number;
}
/**
 * Redistributes existing per-frame fallback node arrays onto a new set of
 * frame line ranges, shifting only the lines that cross a frame boundary.
 *
 * Enhancers never change the plain-text output of the code (they only add or
 * modify highlighting spans), so when a frame's line range is unchanged its
 * fallback is reused by reference without scanning. Only the boundary frames —
 * where lines move into an adjacent frame — are split, and the split walks just
 * the lines that need to move (counting newlines with an early exit) rather
 * than splitting the whole frame or re-deriving text via `toText`.
 *
 * Lines that fall in a gap between ranges (collapsed / dropped lines) have
 * their fallback text discarded.
 *
 * `oldFrames` must be ordered ascending and non-overlapping (gaps are allowed,
 * e.g. when a previous restructure already dropped lines); `ranges` must be
 * ordered ascending. Returns one node array per range, in range order.
 */
export declare function redistributeFrameFallbacks(oldFrames: FrameFallback[], ranges: FrameRangeBounds[]): ElementContent[][];