1/*
2 * This file is part of the MicroPython project, http://micropython.org/
3 *
4 * The MIT License (MIT)
5 *
6 * Copyright (c) 2013, 2014 Damien P. George
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 * THE SOFTWARE.
25 */
26
27#include <stdio.h>
28#include <stdint.h>
29#include <string.h>
30
31#include "py/mpstate.h"
32#include "py/repl.h"
33#include "py/mphal.h"
34#include "lib/mp-readline/readline.h"
35
36#if 0 // print debugging info
37#define DEBUG_PRINT (1)
38#define DEBUG_printf printf
39#else // don't print debugging info
40#define DEBUG_printf(...) (void)0
41#endif
42
43#define READLINE_HIST_SIZE (MP_ARRAY_SIZE(MP_STATE_PORT(readline_hist)))
44
45enum { ESEQ_NONE, ESEQ_ESC, ESEQ_ESC_BRACKET, ESEQ_ESC_BRACKET_DIGIT, ESEQ_ESC_O };
46
47void readline_init0(void) {
48 memset(MP_STATE_PORT(readline_hist), 0, READLINE_HIST_SIZE * sizeof(const char*));
49}
50
51STATIC char *str_dup_maybe(const char *str) {
52 uint32_t len = strlen(str);
53 char *s2 = m_new_maybe(char, len + 1);
54 if (s2 == NULL) {
55 return NULL;
56 }
57 memcpy(s2, str, len + 1);
58 return s2;
59}
60
61// By default assume terminal which implements VT100 commands...
62#ifndef MICROPY_HAL_HAS_VT100
63#define MICROPY_HAL_HAS_VT100 (1)
64#endif
65
66// ...and provide the implementation using them
67#if MICROPY_HAL_HAS_VT100
68STATIC void mp_hal_move_cursor_back(uint pos) {
69 if (pos <= 4) {
70 // fast path for most common case of 1 step back
71 mp_hal_stdout_tx_strn("\b\b\b\b", pos);
72 } else {
73 char vt100_command[6];
74 // snprintf needs space for the terminating null character
75 int n = snprintf(&vt100_command[0], sizeof(vt100_command), "\x1b[%u", pos);
76 if (n > 0) {
77 assert((unsigned)n < sizeof(vt100_command));
78 vt100_command[n] = 'D'; // replace null char
79 mp_hal_stdout_tx_strn(vt100_command, n + 1);
80 }
81 }
82}
83
84STATIC void mp_hal_erase_line_from_cursor(uint n_chars_to_erase) {
85 (void)n_chars_to_erase;
86 mp_hal_stdout_tx_strn("\x1b[K", 3);
87}
88#endif
89
90typedef struct _readline_t {
91 vstr_t *line;
92 size_t orig_line_len;
93 int escape_seq;
94 int hist_cur;
95 size_t cursor_pos;
96 char escape_seq_buf[1];
97 const char *prompt;
98} readline_t;
99
100STATIC readline_t rl;
101
102#if MICROPY_REPL_EMACS_WORDS_MOVE
103STATIC size_t cursor_count_word(int forward) {
104 const char *line_buf = vstr_str(rl.line);
105 size_t pos = rl.cursor_pos;
106 bool in_word = false;
107
108 for (;;) {
109 // if moving backwards and we've reached 0... break
110 if (!forward && pos == 0) {
111 break;
112 }
113 // or if moving forwards and we've reached to the end of line... break
114 else if (forward && pos == vstr_len(rl.line)) {
115 break;
116 }
117
118 if (unichar_isalnum(line_buf[pos + (forward - 1)])) {
119 in_word = true;
120 } else if (in_word) {
121 break;
122 }
123
124 pos += forward ? forward : -1;
125 }
126
127 return forward ? pos - rl.cursor_pos : rl.cursor_pos - pos;
128}
129#endif
130
131int readline_process_char(int c) {
132 size_t last_line_len = rl.line->len;
133 int redraw_step_back = 0;
134 bool redraw_from_cursor = false;
135 int redraw_step_forward = 0;
136 if (rl.escape_seq == ESEQ_NONE) {
137 if (CHAR_CTRL_A <= c && c <= CHAR_CTRL_E && vstr_len(rl.line) == rl.orig_line_len) {
138 // control character with empty line
139 return c;
140 } else if (c == CHAR_CTRL_A) {
141 // CTRL-A with non-empty line is go-to-start-of-line
142 goto home_key;
143 #if MICROPY_REPL_EMACS_KEYS
144 } else if (c == CHAR_CTRL_B) {
145 // CTRL-B with non-empty line is go-back-one-char
146 goto left_arrow_key;
147 #endif
148 } else if (c == CHAR_CTRL_C) {
149 // CTRL-C with non-empty line is cancel
150 return c;
151 #if MICROPY_REPL_EMACS_KEYS
152 } else if (c == CHAR_CTRL_D) {
153 // CTRL-D with non-empty line is delete-at-cursor
154 goto delete_key;
155 #endif
156 } else if (c == CHAR_CTRL_E) {
157 // CTRL-E is go-to-end-of-line
158 goto end_key;
159 #if MICROPY_REPL_EMACS_KEYS
160 } else if (c == CHAR_CTRL_F) {
161 // CTRL-F with non-empty line is go-forward-one-char
162 goto right_arrow_key;
163 } else if (c == CHAR_CTRL_K) {
164 // CTRL-K is kill from cursor to end-of-line, inclusive
165 vstr_cut_tail_bytes(rl.line, last_line_len - rl.cursor_pos);
166 // set redraw parameters
167 redraw_from_cursor = true;
168 } else if (c == CHAR_CTRL_N) {
169 // CTRL-N is go to next line in history
170 goto down_arrow_key;
171 } else if (c == CHAR_CTRL_P) {
172 // CTRL-P is go to previous line in history
173 goto up_arrow_key;
174 } else if (c == CHAR_CTRL_U) {
175 // CTRL-U is kill from beginning-of-line up to cursor
176 vstr_cut_out_bytes(rl.line, rl.orig_line_len, rl.cursor_pos - rl.orig_line_len);
177 // set redraw parameters
178 redraw_step_back = rl.cursor_pos - rl.orig_line_len;
179 redraw_from_cursor = true;
180 #endif
181 #if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
182 } else if (c == CHAR_CTRL_W) {
183 goto backward_kill_word;
184 #endif
185 } else if (c == '\r') {
186 // newline
187 mp_hal_stdout_tx_str("\r\n");
188 readline_push_history(vstr_null_terminated_str(rl.line) + rl.orig_line_len);
189 return 0;
190 } else if (c == 27) {
191 // escape sequence
192 rl.escape_seq = ESEQ_ESC;
193 } else if (c == 8 || c == 127) {
194 // backspace/delete
195 if (rl.cursor_pos > rl.orig_line_len) {
196 // work out how many chars to backspace
197 #if MICROPY_REPL_AUTO_INDENT
198 int nspace = 0;
199 for (size_t i = rl.orig_line_len; i < rl.cursor_pos; i++) {
200 if (rl.line->buf[i] != ' ') {
201 nspace = 0;
202 break;
203 }
204 nspace += 1;
205 }
206 if (nspace < 4) {
207 nspace = 1;
208 } else {
209 nspace = 4;
210 }
211 #else
212 int nspace = 1;
213 #endif
214
215 // do the backspace
216 vstr_cut_out_bytes(rl.line, rl.cursor_pos - nspace, nspace);
217 // set redraw parameters
218 redraw_step_back = nspace;
219 redraw_from_cursor = true;
220 }
221 #if MICROPY_HELPER_REPL
222 } else if (c == 9) {
223 // tab magic
224 const char *compl_str;
225 size_t compl_len = mp_repl_autocomplete(rl.line->buf + rl.orig_line_len, rl.cursor_pos - rl.orig_line_len, &mp_plat_print, &compl_str);
226 if (compl_len == 0) {
227 // no match
228 } else if (compl_len == (size_t)(-1)) {
229 // many matches
230 mp_hal_stdout_tx_str(rl.prompt);
231 mp_hal_stdout_tx_strn(rl.line->buf + rl.orig_line_len, rl.cursor_pos - rl.orig_line_len);
232 redraw_from_cursor = true;
233 } else {
234 // one match
235 for (size_t i = 0; i < compl_len; ++i) {
236 vstr_ins_byte(rl.line, rl.cursor_pos + i, *compl_str++);
237 }
238 // set redraw parameters
239 redraw_from_cursor = true;
240 redraw_step_forward = compl_len;
241 }
242 #endif
243 } else if (32 <= c && c <= 126) {
244 // printable character
245 vstr_ins_char(rl.line, rl.cursor_pos, c);
246 // set redraw parameters
247 redraw_from_cursor = true;
248 redraw_step_forward = 1;
249 }
250 } else if (rl.escape_seq == ESEQ_ESC) {
251 switch (c) {
252 case '[':
253 rl.escape_seq = ESEQ_ESC_BRACKET;
254 break;
255 case 'O':
256 rl.escape_seq = ESEQ_ESC_O;
257 break;
258 #if MICROPY_REPL_EMACS_WORDS_MOVE
259 case 'b':
260#if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
261backward_word:
262#endif
263 redraw_step_back = cursor_count_word(0);
264 rl.escape_seq = ESEQ_NONE;
265 break;
266 case 'f':
267#if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
268forward_word:
269#endif
270 redraw_step_forward = cursor_count_word(1);
271 rl.escape_seq = ESEQ_NONE;
272 break;
273 case 'd':
274 vstr_cut_out_bytes(rl.line, rl.cursor_pos, cursor_count_word(1));
275 redraw_from_cursor = true;
276 rl.escape_seq = ESEQ_NONE;
277 break;
278 case 127:
279#if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
280backward_kill_word:
281#endif
282 redraw_step_back = cursor_count_word(0);
283 vstr_cut_out_bytes(rl.line, rl.cursor_pos - redraw_step_back, redraw_step_back);
284 redraw_from_cursor = true;
285 rl.escape_seq = ESEQ_NONE;
286 break;
287 #endif
288 default:
289 DEBUG_printf("(ESC %d)", c);
290 rl.escape_seq = ESEQ_NONE;
291 break;
292 }
293 } else if (rl.escape_seq == ESEQ_ESC_BRACKET) {
294 if ('0' <= c && c <= '9') {
295 rl.escape_seq = ESEQ_ESC_BRACKET_DIGIT;
296 rl.escape_seq_buf[0] = c;
297 } else {
298 rl.escape_seq = ESEQ_NONE;
299 if (c == 'A') {
300#if MICROPY_REPL_EMACS_KEYS
301up_arrow_key:
302#endif
303 // up arrow
304 if (rl.hist_cur + 1 < (int)READLINE_HIST_SIZE && MP_STATE_PORT(readline_hist)[rl.hist_cur + 1] != NULL) {
305 // increase hist num
306 rl.hist_cur += 1;
307 // set line to history
308 rl.line->len = rl.orig_line_len;
309 vstr_add_str(rl.line, MP_STATE_PORT(readline_hist)[rl.hist_cur]);
310 // set redraw parameters
311 redraw_step_back = rl.cursor_pos - rl.orig_line_len;
312 redraw_from_cursor = true;
313 redraw_step_forward = rl.line->len - rl.orig_line_len;
314 }
315 } else if (c == 'B') {
316#if MICROPY_REPL_EMACS_KEYS
317down_arrow_key:
318#endif
319 // down arrow
320 if (rl.hist_cur >= 0) {
321 // decrease hist num
322 rl.hist_cur -= 1;
323 // set line to history
324 vstr_cut_tail_bytes(rl.line, rl.line->len - rl.orig_line_len);
325 if (rl.hist_cur >= 0) {
326 vstr_add_str(rl.line, MP_STATE_PORT(readline_hist)[rl.hist_cur]);
327 }
328 // set redraw parameters
329 redraw_step_back = rl.cursor_pos - rl.orig_line_len;
330 redraw_from_cursor = true;
331 redraw_step_forward = rl.line->len - rl.orig_line_len;
332 }
333 } else if (c == 'C') {
334#if MICROPY_REPL_EMACS_KEYS
335right_arrow_key:
336#endif
337 // right arrow
338 if (rl.cursor_pos < rl.line->len) {
339 redraw_step_forward = 1;
340 }
341 } else if (c == 'D') {
342#if MICROPY_REPL_EMACS_KEYS
343left_arrow_key:
344#endif
345 // left arrow
346 if (rl.cursor_pos > rl.orig_line_len) {
347 redraw_step_back = 1;
348 }
349 } else if (c == 'H') {
350 // home
351 goto home_key;
352 } else if (c == 'F') {
353 // end
354 goto end_key;
355 } else {
356 DEBUG_printf("(ESC [ %d)", c);
357 }
358 }
359 } else if (rl.escape_seq == ESEQ_ESC_BRACKET_DIGIT) {
360 if (c == '~') {
361 if (rl.escape_seq_buf[0] == '1' || rl.escape_seq_buf[0] == '7') {
362home_key:
363 redraw_step_back = rl.cursor_pos - rl.orig_line_len;
364 } else if (rl.escape_seq_buf[0] == '4' || rl.escape_seq_buf[0] == '8') {
365end_key:
366 redraw_step_forward = rl.line->len - rl.cursor_pos;
367 } else if (rl.escape_seq_buf[0] == '3') {
368 // delete
369#if MICROPY_REPL_EMACS_KEYS
370delete_key:
371#endif
372 if (rl.cursor_pos < rl.line->len) {
373 vstr_cut_out_bytes(rl.line, rl.cursor_pos, 1);
374 redraw_from_cursor = true;
375 }
376 } else {
377 DEBUG_printf("(ESC [ %c %d)", rl.escape_seq_buf[0], c);
378 }
379 #if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
380 } else if (c == ';' && rl.escape_seq_buf[0] == '1') {
381 // ';' is used to separate parameters. so first parameter was '1',
382 // that's used for sequences like ctrl+left, which we will try to parse.
383 // escape_seq state is reset back to ESEQ_ESC_BRACKET, as if we've just received
384 // the opening bracket, because more parameters are to come.
385 // we don't track the parameters themselves to keep low on logic and code size. that
386 // might be required in the future if more complex sequences are added.
387 rl.escape_seq = ESEQ_ESC_BRACKET;
388 // goto away from the state-machine, as rl.escape_seq will be overridden.
389 goto redraw;
390 } else if (rl.escape_seq_buf[0] == '5' && c == 'C') {
391 // ctrl+right
392 goto forward_word;
393 } else if (rl.escape_seq_buf[0] == '5' && c == 'D') {
394 // ctrl+left
395 goto backward_word;
396 #endif
397 } else {
398 DEBUG_printf("(ESC [ %c %d)", rl.escape_seq_buf[0], c);
399 }
400 rl.escape_seq = ESEQ_NONE;
401 } else if (rl.escape_seq == ESEQ_ESC_O) {
402 switch (c) {
403 case 'H':
404 goto home_key;
405 case 'F':
406 goto end_key;
407 default:
408 DEBUG_printf("(ESC O %d)", c);
409 rl.escape_seq = ESEQ_NONE;
410 }
411 } else {
412 rl.escape_seq = ESEQ_NONE;
413 }
414
415#if MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE
416redraw:
417#endif
418
419 // redraw command prompt, efficiently
420 if (redraw_step_back > 0) {
421 mp_hal_move_cursor_back(redraw_step_back);
422 rl.cursor_pos -= redraw_step_back;
423 }
424 if (redraw_from_cursor) {
425 if (rl.line->len < last_line_len) {
426 // erase old chars
427 mp_hal_erase_line_from_cursor(last_line_len - rl.cursor_pos);
428 }
429 // draw new chars
430 mp_hal_stdout_tx_strn(rl.line->buf + rl.cursor_pos, rl.line->len - rl.cursor_pos);
431 // move cursor forward if needed (already moved forward by length of line, so move it back)
432 mp_hal_move_cursor_back(rl.line->len - (rl.cursor_pos + redraw_step_forward));
433 rl.cursor_pos += redraw_step_forward;
434 } else if (redraw_step_forward > 0) {
435 // draw over old chars to move cursor forwards
436 mp_hal_stdout_tx_strn(rl.line->buf + rl.cursor_pos, redraw_step_forward);
437 rl.cursor_pos += redraw_step_forward;
438 }
439
440 return -1;
441}
442
443#if MICROPY_REPL_AUTO_INDENT
444STATIC void readline_auto_indent(void) {
445 vstr_t *line = rl.line;
446 if (line->len > 1 && line->buf[line->len - 1] == '\n') {
447 int i;
448 for (i = line->len - 1; i > 0; i--) {
449 if (line->buf[i - 1] == '\n') {
450 break;
451 }
452 }
453 size_t j;
454 for (j = i; j < line->len; j++) {
455 if (line->buf[j] != ' ') {
456 break;
457 }
458 }
459 // i=start of line; j=first non-space
460 if (i > 0 && j + 1 == line->len) {
461 // previous line is not first line and is all spaces
462 for (size_t k = i - 1; k > 0; --k) {
463 if (line->buf[k - 1] == '\n') {
464 // don't auto-indent if last 2 lines are all spaces
465 return;
466 } else if (line->buf[k - 1] != ' ') {
467 // 2nd previous line is not all spaces
468 break;
469 }
470 }
471 }
472 int n = (j - i) / 4;
473 if (line->buf[line->len - 2] == ':') {
474 n += 1;
475 }
476 while (n-- > 0) {
477 vstr_add_strn(line, " ", 4);
478 mp_hal_stdout_tx_strn(" ", 4);
479 rl.cursor_pos += 4;
480 }
481 }
482}
483#endif
484
485void readline_note_newline(const char *prompt) {
486 rl.orig_line_len = rl.line->len;
487 rl.cursor_pos = rl.orig_line_len;
488 rl.prompt = prompt;
489 mp_hal_stdout_tx_str(prompt);
490 #if MICROPY_REPL_AUTO_INDENT
491 readline_auto_indent();
492 #endif
493}
494
495void readline_init(vstr_t *line, const char *prompt) {
496 rl.line = line;
497 rl.orig_line_len = line->len;
498 rl.escape_seq = ESEQ_NONE;
499 rl.escape_seq_buf[0] = 0;
500 rl.hist_cur = -1;
501 rl.cursor_pos = rl.orig_line_len;
502 rl.prompt = prompt;
503 mp_hal_stdout_tx_str(prompt);
504 #if MICROPY_REPL_AUTO_INDENT
505 readline_auto_indent();
506 #endif
507}
508
509int readline(vstr_t *line, const char *prompt) {
510 readline_init(line, prompt);
511 for (;;) {
512 int c = mp_hal_stdin_rx_chr();
513 int r = readline_process_char(c);
514 if (r >= 0) {
515 return r;
516 }
517 }
518}
519
520void readline_push_history(const char *line) {
521 if (line[0] != '\0'
522 && (MP_STATE_PORT(readline_hist)[0] == NULL
523 || strcmp(MP_STATE_PORT(readline_hist)[0], line) != 0)) {
524 // a line which is not empty and different from the last one
525 // so update the history
526 char *most_recent_hist = str_dup_maybe(line);
527 if (most_recent_hist != NULL) {
528 for (int i = READLINE_HIST_SIZE - 1; i > 0; i--) {
529 MP_STATE_PORT(readline_hist)[i] = MP_STATE_PORT(readline_hist)[i - 1];
530 }
531 MP_STATE_PORT(readline_hist)[0] = most_recent_hist;
532 }
533 }
534}
535