summary refs log tree commit diff
path: root/edit.c
blob: a8f5d4ab798dda1e53b8113b210809d37708e90c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
/* Copyright (C) 2020, 2022  June McEnroe <june@causal.agency>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * Additional permission under GNU GPL version 3 section 7:
 *
 * If you modify this Program, or any covered work, by linking or
 * combining it with OpenSSL (or a modified version of that library),
 * containing parts covered by the terms of the OpenSSL License and the
 * original SSLeay license, the licensors of this Program grant you
 * additional permission to convey the resulting work. Corresponding
 * Source for a non-source form of such a combination shall include the
 * source code for the parts of OpenSSL used as well as that of the
 * covered work.
 */

#include <errno.h>
#include <limits.h>
#include <stdbool.h>
#include <stdlib.h>
#include <wchar.h>
#include <wctype.h>

#include "edit.h"

static bool isword(wchar_t ch) {
	return !iswspace(ch) && !iswpunct(ch);
}

void editFree(struct Edit *e) {
	free(e->buf);
	free(e->cut.buf);
	free(e->mbs.buf);
	e->pos = e->len = e->cap = 0;
	e->cut.len = 0;
	e->mbs.pos = 0;
}

char *editString(struct Edit *e) {
	size_t cap = e->len * MB_CUR_MAX + 1;
	char *buf = realloc(e->mbs.buf, cap);
	if (!buf) return NULL;
	e->mbs.buf = buf;

	const wchar_t *ptr = e->buf;
	size_t len = wcsnrtombs(e->mbs.buf, &ptr, e->pos, cap-1, NULL);
	if (len == (size_t)-1) return NULL;
	e->mbs.pos = len;

	ptr = &e->buf[e->pos];
	size_t n = wcsnrtombs(
		&e->mbs.buf[len], &ptr, e->len - e->pos, cap-1 - len, NULL
	);
	if (n == (size_t)-1) return NULL;
	len += n;

	e->mbs.buf[len] = '\0';
	return e->mbs.buf;
}

int editReserve(struct Edit *e, size_t index, size_t count) {
	if (index > e->len) {
		errno = EINVAL;
		return -1;
	}
	if (e->len + count > e->cap) {
		size_t cap = (e->cap ?: 256);
		while (cap < e->len + count) cap *= 2;
		wchar_t *buf = realloc(e->buf, sizeof(*buf) * cap);
		if (!buf) return -1;
		e->buf = buf;
		e->cap = cap;
	}
	wmemmove(&e->buf[index + count], &e->buf[index], e->len - index);
	e->len += count;
	return 0;
}

int editCopy(struct Edit *e, size_t index, size_t count) {
	if (index + count > e->len) {
		errno = EINVAL;
		return -1;
	}
	wchar_t *buf = realloc(e->cut.buf, sizeof(*buf) * count);
	if (!buf) return -1;
	e->cut.buf = buf;
	wmemcpy(e->cut.buf, &e->buf[index], count);
	e->cut.len = count;
	return 0;
}

int editDelete(struct Edit *e, bool cut, size_t index, size_t count) {
	if (index + count > e->len) {
		errno = EINVAL;
		return -1;
	}
	if (cut && editCopy(e, index, count) < 0) return -1;
	wmemmove(&e->buf[index], &e->buf[index + count], e->len - index - count);
	e->len -= count;
	if (e->pos > e->len) e->pos = e->len;
	return 0;
}

int editFn(struct Edit *e, enum EditFn fn) {
	int ret = 0;
	switch (fn) {
		break; case EditHead: e->pos = 0;
		break; case EditTail: e->pos = e->len;
		break; case EditPrev: if (e->pos) e->pos--;
		break; case EditNext: if (e->pos < e->len) e->pos++;
		break; case EditPrevWord: {
			while (e->pos && !isword(e->buf[e->pos-1])) e->pos--;
			while (e->pos && isword(e->buf[e->pos-1])) e->pos--;
		}
		break; case EditNextWord: {
			while (e->pos < e->len && isword(e->buf[e->pos])) e->pos++;
			while (e->pos < e->len && !isword(e->buf[e->pos])) e->pos++;
		}

		break; case EditDeleteHead: {
			ret = editDelete(e, true, 0, e->pos);
			e->pos = 0;
		}
		break; case EditDeleteTail: {
			ret = editDelete(e, true, e->pos, e->len - e->pos);
		}
		break; case EditDeletePrev: {
			if (e->pos) editDelete(e, false, --e->pos, 1);
		}
		break; case EditDeleteNext: {
			editDelete(e, false, e->pos, 1);
		}
		break; case EditDeletePrevWord: {
			if (!e->pos) break;
			size_t word = e->pos;
			while (word && !isword(e->buf[word-1])) word--;
			while (word && isword(e->buf[word-1])) word--;
			ret = editDelete(e, true, word, e->pos - word);
			e->pos = word;
		}
		break; case EditDeleteNextWord: {
			if (e->pos == e->len) break;
			size_t word = e->pos;
			while (word < e->len && !isword(e->buf[word])) word++;
			while (word < e->len && isword(e->buf[word])) word++;
			ret = editDelete(e, true, e->pos, word - e->pos);
		}

		break; case EditPaste: {
			ret = editReserve(e, e->pos, e->cut.len);
			if (ret == 0) {
				wmemcpy(&e->buf[e->pos], e->cut.buf, e->cut.len);
				e->pos += e->cut.len;
			}
		}
		break; case EditTranspose: {
			if (e->len < 2) break;
			if (!e->pos) e->pos++;
			if (e->pos == e->len) e->pos--;
			wchar_t x = e->buf[e->pos-1];
			e->buf[e->pos-1] = e->buf[e->pos];
			e->buf[e->pos++] = x;
		}
		break; case EditCollapse: {
			size_t ws;
			for (e->pos = 0; e->pos < e->len;) {
				for (; e->pos < e->len && !iswspace(e->buf[e->pos]); ++e->pos);
				for (ws = e->pos; ws < e->len && iswspace(e->buf[ws]); ++ws);
				if (e->pos && ws < e->len) {
					editDelete(e, false, e->pos, ws - e->pos - 1);
					e->buf[e->pos++] = L' ';
				} else {
					editDelete(e, false, e->pos, ws - e->pos);
				}
			}
		}

		break; case EditClear: e->len = e->pos = 0;
	}
	return ret;
}

int editInsert(struct Edit *e, wchar_t ch) {
	char mb[MB_LEN_MAX];
	if (wctomb(mb, ch) < 0) return -1;
	if (editReserve(e, e->pos, 1) < 0) return -1;
	e->buf[e->pos++] = ch;
	return 0;
}

#ifdef TEST
#undef NDEBUG
#include <assert.h>
#include <string.h>

static void fix(struct Edit *e, const char *str) {
	editFn(e, EditClear);
	for (const char *ch = str; *ch; ++ch) {
		editInsert(e, (wchar_t)*ch);
	}
}

static bool eq(struct Edit *e, const char *str1) {
	const char *str2 = &str1[strlen(str1) + 1];
	const char *buf = editString(e);
	return e->mbs.pos == strlen(str1)
		&& !strncmp(buf, str1, e->mbs.pos)
		&& !strcmp(&buf[e->mbs.pos], str2);
}

int main(void) {
	struct Edit e = { .mode = EditEmacs };

	fix(&e, "foo bar");
	editFn(&e, EditHead);
	assert(eq(&e, "\0foo bar"));
	editFn(&e, EditTail);
	assert(eq(&e, "foo bar\0"));
	editFn(&e, EditPrev);
	assert(eq(&e, "foo ba\0r"));
	editFn(&e, EditNext);
	assert(eq(&e, "foo bar\0"));

	fix(&e, "foo, bar");
	editFn(&e, EditPrevWord);
	assert(eq(&e, "foo, \0bar"));
	editFn(&e, EditPrevWord);
	assert(eq(&e, "\0foo, bar"));
	editFn(&e, EditNextWord);
	assert(eq(&e, "foo, \0bar"));
	editFn(&e, EditNextWord);
	assert(eq(&e, "foo, bar\0"));

	fix(&e, "foo bar");
	editFn(&e, EditPrevWord);
	editFn(&e, EditDeleteHead);
	assert(eq(&e, "\0bar"));

	fix(&e, "foo bar");
	editFn(&e, EditPrevWord);
	editFn(&e, EditDeleteTail);
	assert(eq(&e, "foo \0"));

	fix(&e, "foo bar");
	editFn(&e, EditDeletePrev);
	assert(eq(&e, "foo ba\0"));
	editFn(&e, EditHead);
	editFn(&e, EditDeleteNext);
	assert(eq(&e, "\0oo ba"));

	fix(&e, "foo, bar");
	editFn(&e, EditDeletePrevWord);
	assert(eq(&e, "foo, \0"));
	editFn(&e, EditDeletePrevWord);
	assert(eq(&e, "\0"));

	fix(&e, "foo, bar");
	editFn(&e, EditHead);
	editFn(&e, EditDeleteNextWord);
	assert(eq(&e, "\0, bar"));
	editFn(&e, EditDeleteNextWord);
	assert(eq(&e, "\0"));

	fix(&e, "foo bar");
	editFn(&e, EditDeletePrevWord);
	editFn(&e, EditPaste);
	assert(eq(&e, "foo bar\0"));
	editFn(&e, EditPaste);
	assert(eq(&e, "foo barbar\0"));

	fix(&e, "bar");
	editFn(&e, EditTranspose);
	assert(eq(&e, "bra\0"));
	editFn(&e, EditHead);
	editFn(&e, EditTranspose);
	assert(eq(&e, "rb\0a"));
	editFn(&e, EditTranspose);
	assert(eq(&e, "rab\0"));

	fix(&e, "  foo  bar  ");
	editFn(&e, EditCollapse);
	assert(eq(&e, "foo bar\0"));
}

#endif /* TEST */