Commit 3f9f9cac authored by Paul Sokolovsky's avatar Paul Sokolovsky
Browse files

lib/mp-readline: Refactor to support coroutine/event-driven usage.

readline_process_char() can be fed character by character, for example,
received from external event loop. This will allow to integrate MicroPython
into cooperative multitasking systems.
parent 708574b0
......@@ -57,190 +57,220 @@ STATIC char *str_dup_maybe(const char *str) {
return s2;
}
int readline(vstr_t *line, const char *prompt) {
stdout_tx_str(prompt);
int orig_line_len = line->len;
int escape_seq = ESEQ_NONE;
char escape_seq_buf[1] = {0};
int hist_cur = -1;
int cursor_pos = orig_line_len;
for (;;) {
int c = stdin_rx_chr();
int last_line_len = line->len;
int redraw_step_back = 0;
bool redraw_from_cursor = false;
int redraw_step_forward = 0;
if (escape_seq == ESEQ_NONE) {
if (CHAR_CTRL_A <= c && c <= CHAR_CTRL_D && vstr_len(line) == orig_line_len) {
// control character with empty line
return c;
} else if (c == CHAR_CTRL_A) {
// CTRL-A with non-empty line is go-to-start-of-line
goto home_key;
} else if (c == CHAR_CTRL_C) {
// CTRL-C with non-empty line is cancel
return c;
} else if (c == CHAR_CTRL_E) {
// CTRL-E is go-to-end-of-line
goto end_key;
} else if (c == '\r') {
// newline
stdout_tx_str("\r\n");
if (line->len > orig_line_len && (MP_STATE_PORT(readline_hist)[0] == NULL || strcmp(MP_STATE_PORT(readline_hist)[0], line->buf + orig_line_len) != 0)) {
// a line which is not empty and different from the last one
// so update the history
char *most_recent_hist = str_dup_maybe(line->buf + orig_line_len);
if (most_recent_hist != NULL) {
for (int i = READLINE_HIST_SIZE - 1; i > 0; i--) {
MP_STATE_PORT(readline_hist)[i] = MP_STATE_PORT(readline_hist)[i - 1];
}
MP_STATE_PORT(readline_hist)[0] = most_recent_hist;
typedef struct _readline_t {
vstr_t *line;
int orig_line_len;
int escape_seq;
int hist_cur;
int cursor_pos;
char escape_seq_buf[1];
} readline_t;
readline_t rl;
int readline_process_char(int c) {
int last_line_len = rl.line->len;
int redraw_step_back = 0;
bool redraw_from_cursor = false;
int redraw_step_forward = 0;
if (rl.escape_seq == ESEQ_NONE) {
if (CHAR_CTRL_A <= c && c <= CHAR_CTRL_D && vstr_len(rl.line) == rl.orig_line_len) {
// control character with empty line
return c;
} else if (c == CHAR_CTRL_A) {
// CTRL-A with non-empty line is go-to-start-of-line
goto home_key;
} else if (c == CHAR_CTRL_C) {
// CTRL-C with non-empty line is cancel
return c;
} else if (c == CHAR_CTRL_E) {
// CTRL-E is go-to-end-of-line
goto end_key;
} else if (c == '\r') {
// newline
stdout_tx_str("\r\n");
if (rl.line->len > rl.orig_line_len && (MP_STATE_PORT(readline_hist)[0] == NULL || strcmp(MP_STATE_PORT(readline_hist)[0], rl.line->buf + rl.orig_line_len) != 0)) {
// a line which is not empty and different from the last one
// so update the history
char *most_recent_hist = str_dup_maybe(rl.line->buf + rl.orig_line_len);
if (most_recent_hist != NULL) {
for (int i = READLINE_HIST_SIZE - 1; i > 0; i--) {
MP_STATE_PORT(readline_hist)[i] = MP_STATE_PORT(readline_hist)[i - 1];
}
MP_STATE_PORT(readline_hist)[0] = most_recent_hist;
}
return 0;
} else if (c == 27) {
// escape sequence
escape_seq = ESEQ_ESC;
} else if (c == 8 || c == 127) {
// backspace/delete
if (cursor_pos > orig_line_len) {
vstr_cut_out_bytes(line, cursor_pos - 1, 1);
// set redraw parameters
redraw_step_back = 1;
redraw_from_cursor = true;
}
} else if (32 <= c && c <= 126) {
// printable character
vstr_ins_char(line, cursor_pos, c);
}
return 0;
} else if (c == 27) {
// escape sequence
rl.escape_seq = ESEQ_ESC;
} else if (c == 8 || c == 127) {
// backspace/delete
if (rl.cursor_pos > rl.orig_line_len) {
vstr_cut_out_bytes(rl.line, rl.cursor_pos - 1, 1);
// set redraw parameters
redraw_step_back = 1;
redraw_from_cursor = true;
redraw_step_forward = 1;
}
} else if (escape_seq == ESEQ_ESC) {
switch (c) {
case '[':
escape_seq = ESEQ_ESC_BRACKET;
break;
case 'O':
escape_seq = ESEQ_ESC_O;
break;
default:
DEBUG_printf("(ESC %d)", c);
escape_seq = ESEQ_NONE;
}
} else if (escape_seq == ESEQ_ESC_BRACKET) {
if ('0' <= c && c <= '9') {
escape_seq = ESEQ_ESC_BRACKET_DIGIT;
escape_seq_buf[0] = c;
} else {
escape_seq = ESEQ_NONE;
if (c == 'A') {
// up arrow
if (hist_cur + 1 < READLINE_HIST_SIZE && MP_STATE_PORT(readline_hist)[hist_cur + 1] != NULL) {
// increase hist num
hist_cur += 1;
// set line to history
line->len = orig_line_len;
vstr_add_str(line, MP_STATE_PORT(readline_hist)[hist_cur]);
// set redraw parameters
redraw_step_back = cursor_pos - orig_line_len;
redraw_from_cursor = true;
redraw_step_forward = line->len - orig_line_len;
}
} else if (c == 'B') {
// down arrow
if (hist_cur >= 0) {
// decrease hist num
hist_cur -= 1;
// set line to history
vstr_cut_tail_bytes(line, line->len - orig_line_len);
if (hist_cur >= 0) {
vstr_add_str(line, MP_STATE_PORT(readline_hist)[hist_cur]);
}
// set redraw parameters
redraw_step_back = cursor_pos - orig_line_len;
redraw_from_cursor = true;
redraw_step_forward = line->len - orig_line_len;
}
} else if (c == 'C') {
// right arrow
if (cursor_pos < line->len) {
redraw_step_forward = 1;
}
} else if (c == 'D') {
// left arrow
if (cursor_pos > orig_line_len) {
redraw_step_back = 1;
} else if (32 <= c && c <= 126) {
// printable character
vstr_ins_char(rl.line, rl.cursor_pos, c);
// set redraw parameters
redraw_from_cursor = true;
redraw_step_forward = 1;
}
} else if (rl.escape_seq == ESEQ_ESC) {
switch (c) {
case '[':
rl.escape_seq = ESEQ_ESC_BRACKET;
break;
case 'O':
rl.escape_seq = ESEQ_ESC_O;
break;
default:
DEBUG_printf("(ESC %d)", c);
rl.escape_seq = ESEQ_NONE;
}
} else if (rl.escape_seq == ESEQ_ESC_BRACKET) {
if ('0' <= c && c <= '9') {
rl.escape_seq = ESEQ_ESC_BRACKET_DIGIT;
rl.escape_seq_buf[0] = c;
} else {
rl.escape_seq = ESEQ_NONE;
if (c == 'A') {
// up arrow
if (rl.hist_cur + 1 < READLINE_HIST_SIZE && MP_STATE_PORT(readline_hist)[rl.hist_cur + 1] != NULL) {
// increase hist num
rl.hist_cur += 1;
// set line to history
rl.line->len = rl.orig_line_len;
vstr_add_str(rl.line, MP_STATE_PORT(readline_hist)[rl.hist_cur]);
// set redraw parameters
redraw_step_back = rl.cursor_pos - rl.orig_line_len;
redraw_from_cursor = true;
redraw_step_forward = rl.line->len - rl.orig_line_len;
}
} else if (c == 'B') {
// down arrow
if (rl.hist_cur >= 0) {
// decrease hist num
rl.hist_cur -= 1;
// set line to history
vstr_cut_tail_bytes(rl.line, rl.line->len - rl.orig_line_len);
if (rl.hist_cur >= 0) {
vstr_add_str(rl.line, MP_STATE_PORT(readline_hist)[rl.hist_cur]);
}
} else if (c == 'H') {
// home
goto home_key;
} else if (c == 'F') {
// end
goto end_key;
} else {
DEBUG_printf("(ESC [ %d)", c);
// set redraw parameters
redraw_step_back = rl.cursor_pos - rl.orig_line_len;
redraw_from_cursor = true;
redraw_step_forward = rl.line->len - rl.orig_line_len;
}
} else if (c == 'C') {
// right arrow
if (rl.cursor_pos < rl.line->len) {
redraw_step_forward = 1;
}
} else if (c == 'D') {
// left arrow
if (rl.cursor_pos > rl.orig_line_len) {
redraw_step_back = 1;
}
} else if (c == 'H') {
// home
goto home_key;
} else if (c == 'F') {
// end
goto end_key;
} else {
DEBUG_printf("(ESC [ %d)", c);
}
} else if (escape_seq == ESEQ_ESC_BRACKET_DIGIT) {
if (c == '~') {
if (escape_seq_buf[0] == '1' || escape_seq_buf[0] == '7') {
}
} else if (rl.escape_seq == ESEQ_ESC_BRACKET_DIGIT) {
if (c == '~') {
if (rl.escape_seq_buf[0] == '1' || rl.escape_seq_buf[0] == '7') {
home_key:
redraw_step_back = cursor_pos - orig_line_len;
} else if (escape_seq_buf[0] == '4' || escape_seq_buf[0] == '8') {
redraw_step_back = rl.cursor_pos - rl.orig_line_len;
} else if (rl.escape_seq_buf[0] == '4' || rl.escape_seq_buf[0] == '8') {
end_key:
redraw_step_forward = line->len - cursor_pos;
} else {
DEBUG_printf("(ESC [ %c %d)", escape_seq_buf[0], c);
}
redraw_step_forward = rl.line->len - rl.cursor_pos;
} else {
DEBUG_printf("(ESC [ %c %d)", escape_seq_buf[0], c);
}
escape_seq = ESEQ_NONE;
} else if (escape_seq == ESEQ_ESC_O) {
switch (c) {
case 'H':
goto home_key;
case 'F':
goto end_key;
default:
DEBUG_printf("(ESC O %d)", c);
escape_seq = ESEQ_NONE;
DEBUG_printf("(ESC [ %c %d)", rl.escape_seq_buf[0], c);
}
} else {
escape_seq = ESEQ_NONE;
DEBUG_printf("(ESC [ %c %d)", rl.escape_seq_buf[0], c);
}
rl.escape_seq = ESEQ_NONE;
} else if (rl.escape_seq == ESEQ_ESC_O) {
switch (c) {
case 'H':
goto home_key;
case 'F':
goto end_key;
default:
DEBUG_printf("(ESC O %d)", c);
rl.escape_seq = ESEQ_NONE;
}
} else {
rl.escape_seq = ESEQ_NONE;
}
// redraw command prompt, efficiently
// TODO we can probably use some more sophisticated VT100 commands here
if (redraw_step_back > 0) {
for (int i = 0; i < redraw_step_back; i++) {
stdout_tx_str("\b");
}
cursor_pos -= redraw_step_back;
// redraw command prompt, efficiently
// TODO we can probably use some more sophisticated VT100 commands here
if (redraw_step_back > 0) {
for (int i = 0; i < redraw_step_back; i++) {
stdout_tx_str("\b");
}
if (redraw_from_cursor) {
if (line->len < last_line_len) {
// erase old chars
for (int i = cursor_pos; i < last_line_len; i++) {
stdout_tx_str(" ");
}
// step back
for (int i = cursor_pos; i < last_line_len; i++) {
stdout_tx_str("\b");
}
rl.cursor_pos -= redraw_step_back;
}
if (redraw_from_cursor) {
if (rl.line->len < last_line_len) {
// erase old chars
for (int i = rl.cursor_pos; i < last_line_len; i++) {
stdout_tx_str(" ");
}
// draw new chars
stdout_tx_strn(line->buf + cursor_pos, line->len - cursor_pos);
// move cursor forward if needed (already moved forward by length of line, so move it back)
for (int i = cursor_pos + redraw_step_forward; i < line->len; i++) {
// step back
for (int i = rl.cursor_pos; i < last_line_len; i++) {
stdout_tx_str("\b");
}
cursor_pos += redraw_step_forward;
} else if (redraw_step_forward > 0) {
// draw over old chars to move cursor forwards
stdout_tx_strn(line->buf + cursor_pos, redraw_step_forward);
cursor_pos += redraw_step_forward;
}
// draw new chars
stdout_tx_strn(rl.line->buf + rl.cursor_pos, rl.line->len - rl.cursor_pos);
// move cursor forward if needed (already moved forward by length of line, so move it back)
for (int i = rl.cursor_pos + redraw_step_forward; i < rl.line->len; i++) {
stdout_tx_str("\b");
}
rl.cursor_pos += redraw_step_forward;
} else if (redraw_step_forward > 0) {
// draw over old chars to move cursor forwards
stdout_tx_strn(rl.line->buf + rl.cursor_pos, redraw_step_forward);
rl.cursor_pos += redraw_step_forward;
}
return -1;
}
void readline_note_newline() {
rl.orig_line_len = rl.line->len;
rl.cursor_pos = rl.orig_line_len;
}
void readline_init(vstr_t *line) {
rl.line = line;
rl.orig_line_len = line->len;
rl.escape_seq = ESEQ_NONE;
rl.escape_seq_buf[0] = 0;
rl.hist_cur = -1;
rl.cursor_pos = rl.orig_line_len;
}
int readline(vstr_t *line, const char *prompt) {
stdout_tx_str(prompt);
readline_init(line);
for (;;) {
int c = stdin_rx_chr();
int r = readline_process_char(c);
if (r >= 0) {
return r;
}
}
}
......@@ -32,3 +32,7 @@
void readline_init0(void);
int readline(vstr_t *line, const char *prompt);
void readline_init(vstr_t *line);
void readline_note_newline();
int readline_process_char(int c);
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