xref: /openbsd/usr.bin/mg/paragraph.c (revision 0d05d316)
1 /*	$OpenBSD: paragraph.c,v 1.33 2014/10/13 21:01:05 lum Exp $	*/
2 
3 /* This file is in the public domain. */
4 
5 /*
6  * Code for dealing with paragraphs and filling. Adapted from MicroEMACS 3.6
7  * and GNU-ified by mwm@ucbvax.	 Several bug fixes by blarson@usc-oberon.
8  */
9 
10 #include <ctype.h>
11 
12 #include "def.h"
13 
14 static int	fillcol = 70;
15 
16 #define MAXWORD 256
17 
18 /*
19  * Move to start of paragraph.
20  * Move backwards by line, checking from the 1st character forwards for the
21  * existence a non-space. If a non-space character is found, move to the
22  * preceding line. Keep doing this until a line with only spaces is found or
23  * the start of buffer.
24  */
25 /* ARGSUSED */
26 int
27 gotobop(int f, int n)
28 {
29 	int col, nospace;
30 
31 	/* the other way... */
32 	if (n < 0)
33 		return (gotoeop(f, -n));
34 
35 	while (n-- > 0) {
36 		nospace = 0;
37 		while (lback(curwp->w_dotp) != curbp->b_headp) {
38 			curwp->w_doto = 0;
39 			col = 0;
40 
41 			while (col < llength(curwp->w_dotp) &&
42 			    (isspace(lgetc(curwp->w_dotp, col))))
43 				col++;
44 
45 			if (col >= llength(curwp->w_dotp)) {
46 				if (nospace)
47 					break;
48 			} else
49 				nospace = 1;
50 
51 			curwp->w_dotline--;
52 			curwp->w_dotp = lback(curwp->w_dotp);
53 		}
54 	}
55 	/* force screen update */
56 	curwp->w_rflag |= WFMOVE;
57 	return (TRUE);
58 }
59 
60 /*
61  * Move to end of paragraph.
62  * See comments for gotobop(). Same, but moving forwards.
63  */
64 /* ARGSUSED */
65 int
66 gotoeop(int f, int n)
67 {
68 	int col, nospace;
69 
70 	/* the other way... */
71 	if (n < 0)
72 		return (gotobop(f, -n));
73 
74 	/* for each one asked for */
75 	while (n-- > 0) {
76 		nospace = 0;
77 		while (lforw(curwp->w_dotp) != curbp->b_headp) {
78 			col = 0;
79 			curwp->w_doto = 0;
80 
81 			while (col < llength(curwp->w_dotp) &&
82 			    (isspace(lgetc(curwp->w_dotp, col))))
83 				col++;
84 
85 			if (col >= llength(curwp->w_dotp)) {
86 				if (nospace)
87 					break;
88 			} else
89 				nospace = 1;
90 
91 			curwp->w_dotp = lforw(curwp->w_dotp);
92 			curwp->w_dotline++;
93 		}
94 	}
95 	/* covers corner case of no '\n' at end of buffer */
96 	if (lforw(curwp->w_dotp) == curbp->b_headp)
97 		gotoeol(FFRAND, 1);
98 
99 	/* force screen update */
100 	curwp->w_rflag |= WFMOVE;
101 	return (TRUE);
102 }
103 
104 /*
105  * Justify a paragraph.  Fill the current paragraph according to the current
106  * fill column.
107  */
108 /* ARGSUSED */
109 int
110 fillpara(int f, int n)
111 {
112 	int	 c;		/* current char during scan		*/
113 	int	 wordlen;	/* length of current word		*/
114 	int	 clength;	/* position on line during fill		*/
115 	int	 i;		/* index during word copy		*/
116 	int	 eopflag;	/* Are we at the End-Of-Paragraph?	*/
117 	int	 firstflag;	/* first word? (needs no space)		*/
118 	int	 newlength;	/* tentative new line length		*/
119 	int	 eolflag;	/* was at end of line			*/
120 	int	 retval;	/* return value				*/
121 	struct line	*eopline;	/* pointer to line just past EOP	*/
122 	char	 wbuf[MAXWORD];	/* buffer for current word		*/
123 
124 	undo_boundary_enable(FFRAND, 0);
125 
126 	/* record the pointer to the line just past the EOP */
127 	(void)gotoeop(FFRAND, 1);
128 	if (curwp->w_doto != 0) {
129 		/* paragraph ends at end of buffer */
130 		(void)lnewline();
131 		eopline = lforw(curwp->w_dotp);
132 	} else
133 		eopline = curwp->w_dotp;
134 
135 	/* and back top the begining of the paragraph */
136 	(void)gotobop(FFRAND, 1);
137 
138 	/* initialize various info */
139 	while (inword() == 0 && forwchar(FFRAND, 1));
140 
141 	clength = curwp->w_doto;
142 	wordlen = 0;
143 
144 	/* scan through lines, filling words */
145 	firstflag = TRUE;
146 	eopflag = FALSE;
147 	while (!eopflag) {
148 
149 		/* get the next character in the paragraph */
150 		if ((eolflag = (curwp->w_doto == llength(curwp->w_dotp)))) {
151 			c = ' ';
152 			if (lforw(curwp->w_dotp) == eopline)
153 				eopflag = TRUE;
154 		} else
155 			c = lgetc(curwp->w_dotp, curwp->w_doto);
156 
157 		/* and then delete it */
158 		if (ldelete((RSIZE) 1, KNONE) == FALSE && !eopflag) {
159 			retval = FALSE;
160 			goto cleanup;
161 		}
162 
163 		/* if not a separator, just add it in */
164 		if (c != ' ' && c != '\t') {
165 			if (wordlen < MAXWORD - 1)
166 				wbuf[wordlen++] = c;
167 			else {
168 				/*
169 				 * You lose chars beyond MAXWORD if the word
170 				 * is too long. I'm too lazy to fix it now; it
171 				 * just silently truncated the word before,
172 				 * so I get to feel smug.
173 				 */
174 				ewprintf("Word too long!");
175 			}
176 		} else if (wordlen) {
177 
178 			/* calculate tentative new length with word added */
179 			newlength = clength + 1 + wordlen;
180 
181 			/*
182 			 * if at end of line or at doublespace and previous
183 			 * character was one of '.','?','!' doublespace here.
184 			 * behave the same way if a ')' is preceded by a
185 			 * [.?!] and followed by a doublespace.
186 			 */
187 			if ((eolflag ||
188 			    curwp->w_doto == llength(curwp->w_dotp) ||
189 			    (c = lgetc(curwp->w_dotp, curwp->w_doto)) == ' '
190 			    || c == '\t') && (ISEOSP(wbuf[wordlen - 1]) ||
191 			    (wbuf[wordlen - 1] == ')' && wordlen >= 2 &&
192 			    ISEOSP(wbuf[wordlen - 2]))) &&
193 			    wordlen < MAXWORD - 1)
194 				wbuf[wordlen++] = ' ';
195 
196 			/* at a word break with a word waiting */
197 			if (newlength <= fillcol) {
198 				/* add word to current line */
199 				if (!firstflag) {
200 					(void)linsert(1, ' ');
201 					++clength;
202 				}
203 				firstflag = FALSE;
204 			} else {
205 				if (curwp->w_doto > 0 &&
206 				    lgetc(curwp->w_dotp, curwp->w_doto - 1) == ' ') {
207 					curwp->w_doto -= 1;
208 					(void)ldelete((RSIZE) 1, KNONE);
209 				}
210 				/* start a new line */
211 				(void)lnewline();
212 				clength = 0;
213 			}
214 
215 			/* and add the word in in either case */
216 			for (i = 0; i < wordlen; i++) {
217 				(void)linsert(1, wbuf[i]);
218 				++clength;
219 			}
220 			wordlen = 0;
221 		}
222 	}
223 	/* and add a last newline for the end of our new paragraph */
224 	(void)lnewline();
225 
226 	/*
227 	 * We really should wind up where we started, (which is hard to keep
228 	 * track of) but I think the end of the last line is better than the
229 	 * beginning of the blank line.
230 	 */
231 	(void)backchar(FFRAND, 1);
232 	retval = TRUE;
233 cleanup:
234 	undo_boundary_enable(FFRAND, 1);
235 	return (retval);
236 }
237 
238 /*
239  * Delete a paragraph.  Delete n paragraphs starting with the current one.
240  */
241 /* ARGSUSED */
242 int
243 killpara(int f, int n)
244 {
245 	int	status;		/* returned status of functions */
246 
247 	/* for each paragraph to delete */
248 	while (n--) {
249 
250 		/* mark out the end and beginning of the para to delete */
251 		(void)gotoeop(FFRAND, 1);
252 
253 		/* set the mark here */
254 		curwp->w_markp = curwp->w_dotp;
255 		curwp->w_marko = curwp->w_doto;
256 
257 		/* go to the beginning of the paragraph */
258 		(void)gotobop(FFRAND, 1);
259 
260 		/* force us to the beginning of line */
261 		curwp->w_doto = 0;
262 
263 		/* and delete it */
264 		if ((status = killregion(FFRAND, 1)) != TRUE)
265 			return (status);
266 	}
267 	return (TRUE);
268 }
269 
270 /*
271  * Insert char with work wrap.  Check to see if we're past fillcol, and if so,
272  * justify this line.  As a last step, justify the line.
273  */
274 /* ARGSUSED */
275 int
276 fillword(int f, int n)
277 {
278 	char	c;
279 	int	col, i, nce;
280 
281 	for (i = col = 0; col <= fillcol; ++i, ++col) {
282 		if (i == curwp->w_doto)
283 			return selfinsert(f, n);
284 		c = lgetc(curwp->w_dotp, i);
285 		if (c == '\t'
286 #ifdef NOTAB
287 		    && !(curbp->b_flag & BFNOTAB)
288 #endif
289 			)
290 			col |= 0x07;
291 		else if (ISCTRL(c) != FALSE)
292 			++col;
293 	}
294 	if (curwp->w_doto != llength(curwp->w_dotp)) {
295 		(void)selfinsert(f, n);
296 		nce = llength(curwp->w_dotp) - curwp->w_doto;
297 	} else
298 		nce = 0;
299 	curwp->w_doto = i;
300 
301 	if ((c = lgetc(curwp->w_dotp, curwp->w_doto)) != ' ' && c != '\t')
302 		do {
303 			(void)backchar(FFRAND, 1);
304 		} while ((c = lgetc(curwp->w_dotp, curwp->w_doto)) != ' ' &&
305 		    c != '\t' && curwp->w_doto > 0);
306 
307 	if (curwp->w_doto == 0)
308 		do {
309 			(void)forwchar(FFRAND, 1);
310 		} while ((c = lgetc(curwp->w_dotp, curwp->w_doto)) != ' ' &&
311 		    c != '\t' && curwp->w_doto < llength(curwp->w_dotp));
312 
313 	(void)delwhite(FFRAND, 1);
314 	(void)lnewline();
315 	i = llength(curwp->w_dotp) - nce;
316 	curwp->w_doto = i > 0 ? i : 0;
317 	curwp->w_rflag |= WFMOVE;
318 	if (nce == 0 && curwp->w_doto != 0)
319 		return (fillword(f, n));
320 	return (TRUE);
321 }
322 
323 /*
324  * Set fill column to n for justify.
325  */
326 int
327 setfillcol(int f, int n)
328 {
329 	char buf[32], *rep;
330 	const char *es;
331 	int nfill;
332 
333 	if ((f & FFARG) != 0) {
334 		fillcol = n;
335 	} else {
336 		if ((rep = eread("Set fill-column: ", buf, sizeof(buf),
337 		    EFNEW | EFCR)) == NULL)
338 			return (ABORT);
339 		else if (rep[0] == '\0')
340 			return (FALSE);
341 		nfill = strtonum(rep, 0, INT_MAX, &es);
342 		if (es != NULL) {
343 			dobeep();
344 			ewprintf("Invalid fill column: %s", rep);
345 			return (FALSE);
346 		}
347 		fillcol = nfill;
348 		ewprintf("Fill column set to %d", fillcol);
349 	}
350 	return (TRUE);
351 }
352