import { Rectangle, Container } from './geometry';
/**
Group horizontally contiguous elements into containers. Usually this is called
with an array of all text spans on a single page. It traverses through the
elements in their natural order, and starts putting elements into a new
container when there appears to be a sizable vertical jump, which usually
indicates a line break. The large number of resulting containers should roughly
correspond to each line.

containers = empty list of containers
currentContainer = uninitialized empty container
for each span in spans:
  if container is uninitialized
    initialize new currentContainer with span
  else
    if span is within (dx, dy) of currentContainer
      add it to the currentContainer
    else
      add currentContainer to containers
      initialize new currentContainer with span

5 is approximately half the mean font size.
*/
export declare function groupLines<T extends Rectangle>(elements: T[], dy_threshold?: number): Container<T>[];
/**
Group a list of lines into columns (groups of vertically close/overlapping elements)
*/
export declare function groupColumns<T extends Rectangle>(elements: T[], threshold_dx?: number, threshold_dy?: number): Container<T>[];
/**
The given elements should all have approximately the same Y value. This takes
all the TextAtoms (or whatever) that comprise a line, and puts them into a list
of containers, each of which corresponds to a word.
*/
export declare function partitionWords<T extends Rectangle>(elements: T[], spaceWidth?: number): Container<T>[];
/**
Paragraphs are distinguished by an unusual first line. This initial line is
unusual compared to preceding lines, as well as subsequent lines.

If paragraphs are very short, it can be hard to distinguish which are the start
lines and which are the end lines simply by shape, since paragraphs may have
normal positive indentation, or have hanging indentation.

The given lines will come from a variety of different layout components, but in
determining the oddity of the left offset of any given line, we only want to
compare its left offset to the left offsets of other lines in the same layout component.

@param column - A column whose elements are containers of lines of text.
*/
export declare function splitParagraphs<T extends Rectangle>(column: Container<T>, indent_threshold?: number): Container<T>[];