sheet.c File Reference

Prototype implementation of Sheet data structure. More...

#include <stdlib.h>
#include <str.h>
#include <errno.h>
#include <adt/list.h>
#include <align.h>
#include <macros.h>
#include "sheet.h"

Go to the source code of this file.

Enumerations
enum	{ , INITIAL_SIZE = 32 }
Functions
void	sheet_copy_out (sheet_t *sh, spt_t const *spos, spt_t const *epos, char *buf, size_t bufsize, spt_t *fpos)
	Read text from sheet.
int	sheet_delete (sheet_t *sh, spt_t *spos, spt_t *epos)
	Delete text from sheet.
void	sheet_get_cell_pt (sheet_t *sh, coord_t const *coord, enum dir_spec dir, spt_t *pt)
	Get point preceding or following character cell.
void	sheet_get_num_rows (sheet_t *sh, int *rows)
	Get the number of rows in a sheet.
void	sheet_get_row_width (sheet_t *sh, int row, int *length)
	Get the number of character cells a row occupies.
int	sheet_init (sheet_t *sh)
	Initialize an empty sheet.
int	sheet_insert (sheet_t *sh, spt_t *pos, enum dir_spec dir, char *str)
	Insert text into sheet.
void	sheet_place_tag (sheet_t *sh, spt_t const *pt, tag_t *tag)
	Place a tag on the specified s-point.
void	sheet_remove_tag (sheet_t *sh, tag_t *tag)
	Remove a tag from the sheet.
bool	spt_equal (spt_t const *a, spt_t const *b)
	Test if two s-points are equal.
void	spt_get_coord (spt_t const *pos, coord_t *coord)
	Get the coordinates of an s-point.
void	tag_get_pt (tag_t const *tag, spt_t *pt)
	Get s-point on which the tag is located right now.

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Detailed Description

Prototype implementation of Sheet data structure.

The sheet is an abstract data structure representing a piece of text. On top of this data structure we can implement a text editor. It is possible to implement the sheet such that the editor can make small changes to large files or files containing long lines efficiently.

The sheet structure allows basic operations of text insertion, deletion, retrieval and mapping of coordinates to position in the file and vice versa. The text that is inserted or deleted can contain tabs and newlines which are interpreted and properly acted upon.

This is a trivial implementation with poor efficiency with O(N+n) insertion and deletion and O(N) mapping (in both directions), where N is the size of the file and n is the size of the inserted/deleted text.

Definition in file sheet.c.

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