/*
* Copyright (c) 1993-1994 by Xerox Corporation. All rights reserved.
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*
* Author: Hans-J. Boehm (boehm@parc.xerox.com)
*/
/*
* A really simple-minded text editor based on cords.
* Things it does right:
* No size bounds.
* Inbounded undo.
* Shouldn't crash no matter what file you invoke it on (e.g. /vmunix)
* (Make sure /vmunix is not writable before you try this.)
* Scrolls horizontally.
* Things it does wrong:
* It doesn't handle tabs reasonably (use "expand" first).
* The command set is MUCH too small.
* The redisplay algorithm doesn't let curses do the scrolling.
* The rule for moving the window over the file is suboptimal.
*/
/* Boehm, February 6, 1995 12:27 pm PST */
/* Boehm, May 19, 1994 2:20 pm PDT */
#include <stdio.h>
#include "gc.h"
#include "cord.h"
#ifdef THINK_C
#define MACINTOSH
#include <ctype.h>
#endif
#if defined(__BORLANDC__) && !defined(WIN32)
/* If this is DOS or win16, we'll fail anyway. */
/* Might as well assume win32. */
# define WIN32
#endif
#if defined(WIN32)
# include <windows.h>
# include "de_win.h"
#elif defined(MACINTOSH)
# include <console.h>
/* curses emulation. */
# define initscr()
# define endwin()
# define nonl()
# define noecho() csetmode(C_NOECHO, stdout)
# define cbreak() csetmode(C_CBREAK, stdout)
# define refresh()
# define addch(c) putchar(c)
# define standout() cinverse(1, stdout)
# define standend() cinverse(0, stdout)
# define move(line,col) cgotoxy(col + 1, line + 1, stdout)
# define clrtoeol() ccleol(stdout)
# define de_error(s) { fprintf(stderr, s); getchar(); }
# define LINES 25
# define COLS 80
#else
# include <curses.h>
# define de_error(s) { fprintf(stderr, s); sleep(2); }
#endif
#include "de_cmds.h"
/* List of line number to position mappings, in descending order. */
/* There may be holes. */
typedef struct LineMapRep {
int line;
size_t pos;
struct LineMapRep * previous;
} * line_map;
/* List of file versions, one per edit operation */
typedef struct HistoryRep {
CORD file_contents;
struct HistoryRep * previous;
line_map map; /* Invalid for first record "now" */
} * history;
history now = 0;
CORD current; /* == now -> file_contents. */
size_t current_len; /* Current file length. */
line_map current_map = 0; /* Current line no. to pos. map */
size_t current_map_size = 0; /* Number of current_map entries. */
/* Not always accurate, but reset */
/* by prune_map. */
# define MAX_MAP_SIZE 3000
/* Current display position */
int dis_line = 0;
int dis_col = 0;
# define ALL -1
# define NONE - 2
int need_redisplay = 0; /* Line that needs to be redisplayed. */
/* Current cursor position. Always within file. */
int line = 0;
int col = 0;
size_t file_pos = 0; /* Character position corresponding to cursor. */
/* Invalidate line map for lines > i */
void invalidate_map(int i)
{
while(current_map -> line > i) {
current_map = current_map -> previous;
current_map_size--;
}
}
/* Reduce the number of map entries to save space for huge files. */
/* This also affects maps in histories. */
void prune_map()
{
line_map map = current_map;
int start_line = map -> line;
current_map_size = 0;
for(; map != 0; map = map -> previous) {
current_map_size++;
if (map -> line < start_line - LINES && map -> previous != 0) {
map -> previous = map -> previous -> previous;
}
}
}
/* Add mapping entry */
void add_map(int line, size_t pos)
{
line_map new_map = GC_NEW(struct LineMapRep);
if (current_map_size >= MAX_MAP_SIZE) prune_map();
new_map -> line = line;
new_map -> pos = pos;
new_map -> previous = current_map;
current_map = new_map;
current_map_size++;
}
/* Return position of column *c of ith line in */
/* current file. Adjust *c to be within the line.*/
/* A 0 pointer is taken as 0 column. */
/* Returns CORD_NOT_FOUND if i is too big. */
/* Assumes i > dis_line. */
size_t line_pos(int i, int *c)
{
int j;
size_t cur;
size_t next;
line_map map = current_map;
while (map -> line > i) map = map -> previous;
if (map -> line < i - 2) /* rebuild */ invalidate_map(i);
for (j = map -> line, cur = map -> pos; j < i;) {
cur = CORD_chr(current, cur, '\n');
if (cur == current_len-1) return(CORD_NOT_FOUND);
cur++;
if (++j > current_map -> line) add_map(j, cur);
}
if (c != 0) {
next = CORD_chr(current, cur, '\n');
if (next == CORD_NOT_FOUND) next = current_len - 1;
if (next < cur + *c) {
*c = next - cur;
}
cur += *c;
}
return(cur);
}
void add_hist(CORD s)
{
history new_file = GC_NEW(struct HistoryRep);
new_file -> file_contents = current = s;
current_len = CORD_len(s);
new_file -> previous = now;
if (now != 0) now -> map = current_map;
now = new_file;
}
void del_hist(void)
{
now = now -> previous;
current = now -> file_contents;
current_map = now -> map;
current_len = CORD_len(current);
}
/* Current screen_contents; a dynamically allocated array of CORDs */
CORD * screen = 0;
int screen_size = 0;
# ifndef WIN32
/* Replace a line in the curses stdscr. All control characters are */
/* displayed as upper case characters in standout mode. This isn't */
/* terribly appropriate for tabs. */
void replace_line(int i, CORD s)
{
register int c;
CORD_pos p;
size_t len = CORD_len(s);
if (screen == 0 || LINES > screen_size) {
screen_size = LINES;
screen = (CORD *)GC_MALLOC(screen_size * sizeof(CORD));
}
# if !defined(MACINTOSH)
/* A gross workaround for an apparent curses bug: */
if (i == LINES-1 && len == COLS) {
s = CORD_substr(s, 0, CORD_len(s) - 1);
}
# endif
if (CORD_cmp(screen[i], s) != 0) {
move(i, 0); clrtoeol(); move(i,0);
CORD_FOR (p, s) {
c = CORD_pos_fetch(p) & 0x7f;
if (iscntrl(c)) {
standout(); addch(c + 0x40); standend();
} else {
addch(c);
}
}
screen[i] = s;
}
}
#else
# define replace_line(i,s) invalidate_line(i)
#endif
/* Return up to COLS characters of the line of s starting at pos, */
/* returning only characters after the given column. */
CORD retrieve_line(CORD s, size_t pos, unsigned column)
{
CORD candidate = CORD_substr(s, pos, column + COLS);
/* avoids scanning very long lines */
int eol = CORD_chr(candidate, 0, '\n');
int len;
if (eol == CORD_NOT_FOUND) eol = CORD_len(candidate);
len = (int)eol - (int)column;
if (len < 0) len = 0;
return(CORD_substr(s, pos + column, len));
}
# ifdef WIN32
# define refresh();
CORD retrieve_screen_line(int i)
{
register size_t pos;
invalidate_map(dis_line + LINES); /* Prune search */
pos = line_pos(dis_line + i, 0);
if (pos == CORD_NOT_FOUND) return(CORD_EMPTY);
return(retrieve_line(current, pos, dis_col));
}
# endif
/* Display the visible section of the current file */
void redisplay(void)
{
register int i;
invalidate_map(dis_line + LINES); /* Prune search */
for (i = 0; i < LINES; i++) {
if (need_redisplay == ALL || need_redisplay == i) {
register size_t pos = line_pos(dis_line + i, 0);
if (pos == CORD_NOT_FOUND) break;
replace_line(i, retrieve_line(current, pos, dis_col));
if (need_redisplay == i) goto done;
}
}
for (; i < LINES; i++) replace_line(i, CORD_EMPTY);
done:
refresh();
need_redisplay = NONE;
}
int dis_granularity;
/* Update dis_line, dis_col, and dis_pos to make cursor visible. */
/* Assumes line, col, dis_line, dis_pos are in bounds. */
void normalize_display()
{
int old_line = dis_line;
int old_col = dis_col;
dis_granularity = 1;
if (LINES > 15 && COLS > 15) dis_granularity = 2;
while (dis_line > line) dis_line -= dis_granularity;
while (dis_col > col) dis_col -= dis_granularity;
while (line >= dis_line + LINES) dis_line += dis_granularity;
while (col >= dis_col + COLS) dis_col += dis_granularity;
if (old_line != dis_line || old_col != dis_col) {
need_redisplay = ALL;
}
}
# if defined(WIN32)
# elif defined(MACINTOSH)
# define move_cursor(x,y) cgotoxy(x + 1, y + 1, stdout)
# else
# define move_cursor(x,y) move(y,x)
# endif
/* Adjust display so that cursor is visible; move cursor into position */
/* Update screen if necessary. */
void fix_cursor(void)
{
normalize_display();
if (need_redisplay != NONE) redisplay();
move_cursor(col - dis_col, line - dis_line);
refresh();
# ifndef WIN32
fflush(stdout);
# endif
}
/* Make sure line, col, and dis_pos are somewhere inside file. */
/* Recompute file_pos. Assumes dis_pos is accurate or past eof */
void fix_pos()
{
int my_col = col;
if ((size_t)line > current_len) line = current_len;
file_pos = line_pos(line, &my_col);
if (file_pos == CORD_NOT_FOUND) {
for (line = current_map -> line, file_pos = current_map -> pos;
file_pos < current_len;
line++, file_pos = CORD_chr(current, file_pos, '\n') + 1);
line--;
file_pos = line_pos(line, &col);
} else {
col = my_col;
}
}
#if defined(WIN32)
# define beep() Beep(1000 /* Hz */, 300 /* msecs */)
#elif defined(MACINTOSH)
# define beep() SysBeep(1)
#else
/*
* beep() is part of some curses packages and not others.
* We try to match the type of the builtin one, if any.
*/
#ifdef __STDC__
int beep(void)
#else
int beep()
#endif
{
putc('\007', stderr);
return(0);
}
#endif
# define NO_PREFIX -1
# define BARE_PREFIX -2
int repeat_count = NO_PREFIX; /* Current command prefix. */
int locate_mode = 0; /* Currently between 2 ^Ls */
CORD locate_string = CORD_EMPTY; /* Current search string. */
char * arg_file_name;
#ifdef WIN32
/* Change the current position to whatever is currently displayed at */
/* the given SCREEN coordinates. */
void set_position(int c, int l)
{
line = l + dis_line;
col = c + dis_col;
fix_pos();
move_cursor(col - dis_col, line - dis_line);
}
#endif /* WIN32 */
/* Perform the command associated with character c. C may be an */
/* integer > 256 denoting a windows command, one of the above control */
/* characters, or another ASCII character to be used as either a */
/* character to be inserted, a repeat count, or a search string, */
/* depending on the current state. */
void do_command(int c)
{
int i;
int need_fix_pos;
FILE * out;
if ( c == '\r') c = '\n';
if (locate_mode) {
size_t new_pos;
if (c == LOCATE) {
locate_mode = 0;
locate_string = CORD_EMPTY;
return;
}
locate_string = CORD_cat_char(locate_string, (char)c);
new_pos = CORD_str(current, file_pos - CORD_len(locate_string) + 1,
locate_string);
if (new_pos != CORD_NOT_FOUND) {
need_redisplay = ALL;
new_pos += CORD_len(locate_string);
for (;;) {
file_pos = line_pos(line + 1, 0);
if (file_pos > new_pos) break;
line++;
}
col = new_pos - line_pos(line, 0);
file_pos = new_pos;
fix_cursor();
} else {
locate_string = CORD_substr(locate_string, 0,
CORD_len(locate_string) - 1);
beep();
}
return;
}
if (c == REPEAT) {
repeat_count = BARE_PREFIX; return;
} else if (c < 0x100 && isdigit(c)){
if (repeat_count == BARE_PREFIX) {
repeat_count = c - '0'; return;
} else if (repeat_count != NO_PREFIX) {
repeat_count = 10 * repeat_count + c - '0'; return;
}
}
if (repeat_count == NO_PREFIX) repeat_count = 1;
if (repeat_count == BARE_PREFIX && (c == UP || c == DOWN)) {
repeat_count = LINES - dis_granularity;
}
if (repeat_count == BARE_PREFIX) repeat_count = 8;
need_fix_pos = 0;
for (i = 0; i < repeat_count; i++) {
switch(c) {
case LOCATE:
locate_mode = 1;
break;
case TOP:
line = col = file_pos = 0;
break;
case UP:
if (line != 0) {
line--;
need_fix_pos = 1;
}
break;
case DOWN:
line++;
need_fix_pos = 1;
break;
case LEFT:
if (col != 0) {
col--; file_pos--;
}
break;
case RIGHT:
if (CORD_fetch(current, file_pos) == '\n') break;
col++; file_pos++;
break;
case UNDO:
del_hist();
need_redisplay = ALL; need_fix_pos = 1;
break;
case BS:
if (col == 0) {
beep();
break;
}
col--; file_pos--;
/* fall through: */
case DEL:
if (file_pos == current_len-1) break;
/* Can't delete trailing newline */
if (CORD_fetch(current, file_pos) == '\n') {
need_redisplay = ALL; need_fix_pos = 1;
} else {
need_redisplay = line - dis_line;
}
add_hist(CORD_cat(
CORD_substr(current, 0, file_pos),
CORD_substr(current, file_pos+1, current_len)));
invalidate_map(line);
break;
case WRITE:
{
CORD name = CORD_cat(CORD_from_char_star(arg_file_name),
".new");
if ((out = fopen(CORD_to_const_char_star(name), "wb")) == NULL
|| CORD_put(current, out) == EOF) {
de_error("Write failed\n");
need_redisplay = ALL;
} else {
fclose(out);
}
}
break;
default:
{
CORD left_part = CORD_substr(current, 0, file_pos);
CORD right_part = CORD_substr(current, file_pos, current_len);
add_hist(CORD_cat(CORD_cat_char(left_part, (char)c),
right_part));
invalidate_map(line);
if (c == '\n') {
col = 0; line++; file_pos++;
need_redisplay = ALL;
} else {
col++; file_pos++;
need_redisplay = line - dis_line;
}
break;
}
}
}
if (need_fix_pos) fix_pos();
fix_cursor();
repeat_count = NO_PREFIX;
}
/* OS independent initialization */
void generic_init(void)
{
FILE * f;
CORD initial;
if ((f = fopen(arg_file_name, "rb")) == NULL) {
initial = "\n";
} else {
initial = CORD_from_file(f);
if (initial == CORD_EMPTY
|| CORD_fetch(initial, CORD_len(initial)-1) != '\n') {
initial = CORD_cat(initial, "\n");
}
}
add_map(0,0);
add_hist(initial);
now -> map = current_map;
now -> previous = now; /* Can't back up further: beginning of the world */
need_redisplay = ALL;
fix_cursor();
}
#ifndef WIN32
main(argc, argv)
int argc;
char ** argv;
{
int c;
#if defined(MACINTOSH)
console_options.title = "\pDumb Editor";
cshow(stdout);
GC_init();
argc = ccommand(&argv);
#endif
if (argc != 2) goto usage;
arg_file_name = argv[1];
setvbuf(stdout, GC_MALLOC_ATOMIC(8192), _IOFBF, 8192);
initscr();
noecho(); nonl(); cbreak();
generic_init();
while ((c = getchar()) != QUIT) {
if (c == EOF) break;
do_command(c);
}
done:
move(LINES-1, 0);
clrtoeol();
refresh();
nl();
echo();
endwin();
exit(0);
usage:
fprintf(stderr, "Usage: %s file\n", argv[0]);
fprintf(stderr, "Cursor keys: ^B(left) ^F(right) ^P(up) ^N(down)\n");
fprintf(stderr, "Undo: ^U Write to <file>.new: ^W");
fprintf(stderr, "Quit:^D Repeat count: ^R[n]\n");
fprintf(stderr, "Top: ^T Locate (search, find): ^L text ^L\n");
exit(1);
}
#endif /* !WIN32 */
