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vi: improvements to undo

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The left shift operator ('<') didn't support undo at all; right
shift ('>') required changes to be undone separately for each line.
Allow both types of shift to be undone as a single operation.

Also, neither traditional vi nor vim yank the lines being shifted by
the '<' and '>' commands, so remove that call to yank_delete();

When a repetition count was specified for the '~', 'x', 'X' or 's'
commands the changes had to be undone one character at a time.
Allow undo as a single operation (though the delete and change
parts of the 's' command still have to be undone separately).

function                                             old     new   delta
undo_push_insert                                      37      40      +3
do_cmd                                              4695    4663     -32
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 3/-32)             Total: -29 bytes

v2: Don't break build when FEATURE_VI_UNDO is  disabled.  Don't reset
    'undo_del' too early in '~' handling code.  Code shrink '~'.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Ron Yorston 2021-04-10 10:20:31 +01:00 committed by Denys Vlasenko
parent e577afca7c
commit b18c7bf702
1 changed files with 22 additions and 13 deletions
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35
editors/vi.c
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@ -3213,6 +3213,10 @@ static void do_cmd(int c)
int dir;
int cnt, i, j;
int c1;
#if ENABLE_FEATURE_VI_UNDO
int allow_undo = ALLOW_UNDO;
int undo_del = UNDO_DEL;
#endif
// c1 = c; // quiet the compiler
// cnt = yf = 0; // quiet the compiler
@ -3614,24 +3618,29 @@ static void do_cmd(int c)
cnt = count_lines(text, dot); // remember what line we are on
if (find_range(&p, &q, c) == -1)
goto dc6;
yank_delete(p, q, WHOLE, YANKONLY, NO_UNDO); // save copy before change
i = count_lines(p, q); // # of lines we are shifting
for ( ; i > 0; i--, p = next_line(p)) {
if (c == '<') {
// shift left- remove tab or 8 spaces
if (*p == '\t') {
// shrink buffer 1 char
text_hole_delete(p, p, NO_UNDO);
text_hole_delete(p, p, allow_undo);
} else if (*p == ' ') {
// we should be calculating columns, not just SPACE
for (j = 0; *p == ' ' && j < tabstop; j++) {
text_hole_delete(p, p, NO_UNDO);
text_hole_delete(p, p, allow_undo);
#if ENABLE_FEATURE_VI_UNDO
allow_undo = ALLOW_UNDO_CHAIN;
#endif
}
}
} else if (c == '>') {
} else /* if (c == '>') */ {
// shift right -- add tab or 8 spaces
char_insert(p, '\t', ALLOW_UNDO);
char_insert(p, '\t', allow_undo);
}
#if ENABLE_FEATURE_VI_UNDO
allow_undo = ALLOW_UNDO_CHAIN;
#endif
}
dot = find_line(cnt); // what line were we on
dot_skip_over_ws();
@ -3785,7 +3794,10 @@ static void do_cmd(int c)
if (dot[dir] != '\n') {
if (c == 'X')
dot--; // delete prev char
dot = yank_delete(dot, dot, PARTIAL, YANKDEL, ALLOW_UNDO); // delete char
dot = yank_delete(dot, dot, PARTIAL, YANKDEL, allow_undo); // delete char
#if ENABLE_FEATURE_VI_UNDO
allow_undo = ALLOW_UNDO_CHAIN;
#endif
}
} while (--cmdcnt > 0);
end_cmd_q(); // stop adding to q
@ -3945,14 +3957,11 @@ static void do_cmd(int c)
case '~': // ~- flip the case of letters a-z -> A-Z
do {
#if ENABLE_FEATURE_VI_UNDO
if (islower(*dot)) {
undo_push(dot, 1, UNDO_DEL);
*dot = toupper(*dot);
undo_push(dot, 1, UNDO_INS_CHAIN);
} else if (isupper(*dot)) {
undo_push(dot, 1, UNDO_DEL);
*dot = tolower(*dot);
if (isalpha(*dot)) {
undo_push(dot, 1, undo_del);
*dot = islower(*dot) ? toupper(*dot) : tolower(*dot);
undo_push(dot, 1, UNDO_INS_CHAIN);
undo_del = UNDO_DEL_CHAIN;
}
#else
if (islower(*dot)) {