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circuitpython/shared/readline/readline.c
Damien George 6d401be4dd shared/readline: Disable auto-indent if space/tab follows added indent. 
Auto-indent still works as the default behaviour, but it is now undone and
disabled if there is a space/tab immediately after an automatically-added
indent.  This makes the REPL behaviour closer to CPython, and in particular
allows text to be pasted at the normal REPL.

Addresses issue #7925.

Signed-off-by: Damien George <damien@micropython.org>
2022-04-22 17:00:16 +10:00

580 lines
20 KiB
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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include "py/mpstate.h"
#include "py/repl.h"
#include "py/mphal.h"
#include "shared/readline/readline.h"
#if 0 // print debugging info
#define DEBUG_PRINT (1)
#define DEBUG_printf printf
#else // don't print debugging info
#define DEBUG_printf(...) (void)0
#endif
#define READLINE_HIST_SIZE (MP_ARRAY_SIZE(MP_STATE_PORT(readline_hist)))
// flags for readline_t.auto_indent_state
#define AUTO_INDENT_ENABLED (0x01)
#define AUTO_INDENT_JUST_ADDED (0x02)
enum { ESEQ_NONE, ESEQ_ESC, ESEQ_ESC_BRACKET, ESEQ_ESC_BRACKET_DIGIT, ESEQ_ESC_O };
void readline_init0(void) {
memset(MP_STATE_PORT(readline_hist), 0, READLINE_HIST_SIZE * sizeof(const char*));
}
STATIC char *str_dup_maybe(const char *str) {
uint32_t len = strlen(str);
char *s2 = m_new_maybe(char, len + 1);
if (s2 == NULL) {
return NULL;
}
memcpy(s2, str, len + 1);
return s2;
}
// By default assume terminal which implements VT100 commands...
#ifndef MICROPY_HAL_HAS_VT100
#define MICROPY_HAL_HAS_VT100 (1)
#endif
// ...and provide the implementation using them
#if MICROPY_HAL_HAS_VT100
STATIC void mp_hal_move_cursor_back(uint pos) {
if (pos <= 4) {
// fast path for most common case of 1 step back
mp_hal_stdout_tx_strn("\b\b\b\b", pos);
} else {
char vt100_command[6];
// snprintf needs space for the terminating null character
int n = snprintf(&vt100_command[0], sizeof(vt100_command), "\x1b[%u", pos);
if (n > 0) {
assert((unsigned)n < sizeof(vt100_command));
vt100_command[n] = 'D'; // replace null char
mp_hal_stdout_tx_strn(vt100_command, n + 1);
}
}
}
STATIC void mp_hal_erase_line_from_cursor(uint n_chars_to_erase) {
(void)n_chars_to_erase;
mp_hal_stdout_tx_strn("\x1b[K", 3);
}
#endif
typedef struct _readline_t {
vstr_t *line;
size_t orig_line_len;
int escape_seq;
int hist_cur;
size_t cursor_pos;
char escape_seq_buf[1];
#if MICROPY_REPL_AUTO_INDENT
uint8_t auto_indent_state;
#endif
const char *prompt;
} readline_t;
STATIC readline_t rl;
#if MICROPY_REPL_EMACS_WORDS_MOVE
STATIC size_t cursor_count_word(int forward) {
const char *line_buf = vstr_str(rl.line);
size_t pos = rl.cursor_pos;
bool in_word = false;
for (;;) {
// if moving backwards and we've reached 0... break
if (!forward && pos == 0) {
break;
}
// or if moving forwards and we've reached to the end of line... break
else if (forward && pos == vstr_len(rl.line)) {
break;
}
if (unichar_isalnum(line_buf[pos + (forward - 1)])) {
in_word = true;
} else if (in_word) {
break;
}
pos += forward ? forward : -1;
}
return forward ? pos - rl.cursor_pos : rl.cursor_pos - pos;
}
#endif
int readline_process_char(int c) {
size_t 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_E && 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;
#if MICROPY_REPL_EMACS_KEYS
} else if (c == CHAR_CTRL_B) {
// CTRL-B with non-empty line is go-back-one-char
goto left_arrow_key;
#endif
} else if (c == CHAR_CTRL_C) {
// CTRL-C with non-empty line is cancel
return c;
#if MICROPY_REPL_EMACS_KEYS
} else if (c == CHAR_CTRL_D) {
// CTRL-D with non-empty line is delete-at-cursor
goto delete_key;
#endif
} else if (c == CHAR_CTRL_E) {
// CTRL-E is go-to-end-of-line
goto end_key;
#if MICROPY_REPL_EMACS_KEYS
} else if (c == CHAR_CTRL_F) {
// CTRL-F with non-empty line is go-forward-one-char
goto right_arrow_key;
} else if (c == CHAR_CTRL_K) {
// CTRL-K is kill from cursor to end-of-line, inclusive
vstr_cut_tail_bytes(rl.line, last_line_len - rl.cursor_pos);
// set redraw parameters
redraw_from_cursor = true;
} else if (c == CHAR_CTRL_N) {
// CTRL-N is go to next line in history
goto down_arrow_key;
} else if (c == CHAR_CTRL_P) {
// CTRL-P is go to previous line in history
goto up_arrow_key;
} else if (c == CHAR_CTRL_U) {
// CTRL-U is kill from beginning-of-line up to cursor
vstr_cut_out_bytes(rl.line, rl.orig_line_len, rl.cursor_pos - rl.orig_line_len);
// set redraw parameters
redraw_step_back = rl.cursor_pos - rl.orig_line_len;
redraw_from_cursor = true;
#endif
#if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
} else if (c == CHAR_CTRL_W) {
goto backward_kill_word;
#endif
} else if (c == '\r') {
// newline
mp_hal_stdout_tx_str("\r\n");
readline_push_history(vstr_null_terminated_str(rl.line) + rl.orig_line_len);
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) {
// work out how many chars to backspace
#if MICROPY_REPL_AUTO_INDENT
int nspace = 0;
for (size_t i = rl.orig_line_len; i < rl.cursor_pos; i++) {
if (rl.line->buf[i] != ' ') {
nspace = 0;
break;
}
nspace += 1;
}
if (nspace < 4) {
nspace = 1;
} else {
nspace = 4;
}
#else
int nspace = 1;
#endif
// do the backspace
vstr_cut_out_bytes(rl.line, rl.cursor_pos - nspace, nspace);
// set redraw parameters
redraw_step_back = nspace;
redraw_from_cursor = true;
}
#if MICROPY_REPL_AUTO_INDENT
} else if ((rl.auto_indent_state & AUTO_INDENT_JUST_ADDED) && (c == 9 || c == ' ')) {
// tab/space after auto-indent: disable auto-indent
// - if it's a tab then leave existing indent
// - if it's a space then remove 3 spaces from existing indent
rl.auto_indent_state = 0;
if (c == ' ') {
redraw_step_back = 3;
vstr_cut_tail_bytes(rl.line, 3);
}
#endif
#if MICROPY_HELPER_REPL
} else if (c == 9) {
// tab magic
const char *compl_str;
size_t compl_len;
if (vstr_len(rl.line) != 0 && unichar_isspace(vstr_str(rl.line)[rl.cursor_pos - 1])) {
// expand tab to 4 spaces if it follows whitespace:
// - includes the case of additional indenting
// - includes the case of indenting the start of a line that's not the first line,
// because a newline will be the previous character
// - doesn't include the case when at the start of the first line, because we still
// want to use auto-complete there
compl_str = " ";
compl_len = 4;
} else {
// try to auto-complete a word
const char *cur_line_buf = vstr_str(rl.line) + rl.orig_line_len;
size_t cur_line_len = rl.cursor_pos - rl.orig_line_len;
compl_len = mp_repl_autocomplete(cur_line_buf, cur_line_len, &mp_plat_print, &compl_str);
}
if (compl_len == 0) {
// no match
} else if (compl_len == (size_t)(-1)) {
// many matches
mp_hal_stdout_tx_str(rl.prompt);
mp_hal_stdout_tx_strn(rl.line->buf + rl.orig_line_len, rl.cursor_pos - rl.orig_line_len);
redraw_from_cursor = true;
} else {
// one match
for (size_t i = 0; i < compl_len; ++i) {
vstr_ins_byte(rl.line, rl.cursor_pos + i, *compl_str++);
}
// set redraw parameters
redraw_from_cursor = true;
redraw_step_forward = compl_len;
}
#endif
} 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;
#if MICROPY_REPL_EMACS_WORDS_MOVE
case 'b':
#if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
backward_word:
#endif
redraw_step_back = cursor_count_word(0);
rl.escape_seq = ESEQ_NONE;
break;
case 'f':
#if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
forward_word:
#endif
redraw_step_forward = cursor_count_word(1);
rl.escape_seq = ESEQ_NONE;
break;
case 'd':
vstr_cut_out_bytes(rl.line, rl.cursor_pos, cursor_count_word(1));
redraw_from_cursor = true;
rl.escape_seq = ESEQ_NONE;
break;
case 127:
#if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
backward_kill_word:
#endif
redraw_step_back = cursor_count_word(0);
vstr_cut_out_bytes(rl.line, rl.cursor_pos - redraw_step_back, redraw_step_back);
redraw_from_cursor = true;
rl.escape_seq = ESEQ_NONE;
break;
#endif
default:
DEBUG_printf("(ESC %d)", c);
rl.escape_seq = ESEQ_NONE;
break;
}
} 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') {
#if MICROPY_REPL_EMACS_KEYS
up_arrow_key:
#endif
// up arrow
if (rl.hist_cur + 1 < (int)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') {
#if MICROPY_REPL_EMACS_KEYS
down_arrow_key:
#endif
// 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]);
}
// 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') {
#if MICROPY_REPL_EMACS_KEYS
right_arrow_key:
#endif
// right arrow
if (rl.cursor_pos < rl.line->len) {
redraw_step_forward = 1;
}
} else if (c == 'D') {
#if MICROPY_REPL_EMACS_KEYS
left_arrow_key:
#endif
// 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 (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 = 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 = rl.line->len - rl.cursor_pos;
} else if (rl.escape_seq_buf[0] == '3') {
// delete
#if MICROPY_REPL_EMACS_KEYS
delete_key:
#endif
if (rl.cursor_pos < rl.line->len) {
vstr_cut_out_bytes(rl.line, rl.cursor_pos, 1);
redraw_from_cursor = true;
}
} else {
DEBUG_printf("(ESC [ %c %d)", rl.escape_seq_buf[0], c);
}
#if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
} else if (c == ';' && rl.escape_seq_buf[0] == '1') {
// ';' is used to separate parameters. so first parameter was '1',
// that's used for sequences like ctrl+left, which we will try to parse.
// escape_seq state is reset back to ESEQ_ESC_BRACKET, as if we've just received
// the opening bracket, because more parameters are to come.
// we don't track the parameters themselves to keep low on logic and code size. that
// might be required in the future if more complex sequences are added.
rl.escape_seq = ESEQ_ESC_BRACKET;
// goto away from the state-machine, as rl.escape_seq will be overridden.
goto redraw;
} else if (rl.escape_seq_buf[0] == '5' && c == 'C') {
// ctrl+right
goto forward_word;
} else if (rl.escape_seq_buf[0] == '5' && c == 'D') {
// ctrl+left
goto backward_word;
#endif
} else {
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;
}
#if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
redraw:
#endif
// redraw command prompt, efficiently
if (redraw_step_back > 0) {
mp_hal_move_cursor_back(redraw_step_back);
rl.cursor_pos -= redraw_step_back;
}
if (redraw_from_cursor) {
if (rl.line->len < last_line_len) {
// erase old chars
mp_hal_erase_line_from_cursor(last_line_len - rl.cursor_pos);
}
// draw new chars
mp_hal_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)
mp_hal_move_cursor_back(rl.line->len - (rl.cursor_pos + redraw_step_forward));
rl.cursor_pos += redraw_step_forward;
} else if (redraw_step_forward > 0) {
// draw over old chars to move cursor forwards
mp_hal_stdout_tx_strn(rl.line->buf + rl.cursor_pos, redraw_step_forward);
rl.cursor_pos += redraw_step_forward;
}
#if MICROPY_REPL_AUTO_INDENT
rl.auto_indent_state &= ~AUTO_INDENT_JUST_ADDED;
#endif
return -1;
}
#if MICROPY_REPL_AUTO_INDENT
STATIC void readline_auto_indent(void) {
if (!(rl.auto_indent_state & AUTO_INDENT_ENABLED)) {
return;
}
vstr_t *line = rl.line;
if (line->len > 1 && line->buf[line->len - 1] == '\n') {
int i;
for (i = line->len - 1; i > 0; i--) {
if (line->buf[i - 1] == '\n') {
break;
}
}
size_t j;
for (j = i; j < line->len; j++) {
if (line->buf[j] != ' ') {
break;
}
}
// i=start of line; j=first non-space
if (i > 0 && j + 1 == line->len) {
// previous line is not first line and is all spaces
for (size_t k = i - 1; k > 0; --k) {
if (line->buf[k - 1] == '\n') {
// don't auto-indent if last 2 lines are all spaces
return;
} else if (line->buf[k - 1] != ' ') {
// 2nd previous line is not all spaces
break;
}
}
}
int n = (j - i) / 4;
if (line->buf[line->len - 2] == ':') {
n += 1;
}
while (n-- > 0) {
vstr_add_strn(line, " ", 4);
mp_hal_stdout_tx_strn(" ", 4);
rl.cursor_pos += 4;
rl.auto_indent_state |= AUTO_INDENT_JUST_ADDED;
}
}
}
#endif
void readline_note_newline(const char *prompt) {
rl.orig_line_len = rl.line->len;
rl.cursor_pos = rl.orig_line_len;
rl.prompt = prompt;
mp_hal_stdout_tx_str(prompt);
#if MICROPY_REPL_AUTO_INDENT
readline_auto_indent();
#endif
}
void readline_init(vstr_t *line, const char *prompt) {
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;
rl.prompt = prompt;
mp_hal_stdout_tx_str(prompt);
#if MICROPY_REPL_AUTO_INDENT
if (vstr_len(line) == 0) {
// start with auto-indent enabled
rl.auto_indent_state = AUTO_INDENT_ENABLED;
}
readline_auto_indent();
#endif
}
int readline(vstr_t *line, const char *prompt) {
readline_init(line, prompt);
for (;;) {
int c = mp_hal_stdin_rx_chr();
int r = readline_process_char(c);
if (r >= 0) {
return r;
}
}
}
void readline_push_history(const char *line) {
if (line[0] != '\0'
&& (MP_STATE_PORT(readline_hist)[0] == NULL
|| strcmp(MP_STATE_PORT(readline_hist)[0], line) != 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);
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;
}
}
}
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