src/usr.bin/mg/paragraph.c

488 lines
11 KiB
C

/* $OpenBSD: paragraph.c,v 1.49 2023/04/21 13:39:37 op Exp $ */
/* This file is in the public domain. */
/*
* Code for dealing with paragraphs and filling. Adapted from MicroEMACS 3.6
* and GNU-ified by mwm@ucbvax. Several bug fixes by blarson@usc-oberon.
*/
#include <sys/queue.h>
#include <ctype.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include "def.h"
static int fillcol = 70;
#define MAXWORD 256
static int findpara(void);
static int do_gotoeop(int, int, int *);
/*
* Move to start of paragraph.
* Move backwards by line, checking from the 1st character forwards for the
* existence a non-space. If a non-space character is found, move to the
* preceding line. Keep doing this until a line with only spaces is found or
* the start of buffer.
*/
int
gotobop(int f, int n)
{
int col, nospace;
/* the other way... */
if (n < 0)
return (gotoeop(f, -n));
while (n-- > 0) {
nospace = 0;
while (lback(curwp->w_dotp) != curbp->b_headp) {
curwp->w_doto = 0;
col = 0;
while (col < llength(curwp->w_dotp) &&
(isspace(lgetc(curwp->w_dotp, col))))
col++;
if (col >= llength(curwp->w_dotp)) {
if (nospace)
break;
} else
nospace = 1;
curwp->w_dotline--;
curwp->w_dotp = lback(curwp->w_dotp);
}
}
/* force screen update */
curwp->w_rflag |= WFMOVE;
return (TRUE);
}
/*
* Move to end of paragraph.
* See comments for gotobop(). Same, but moving forwards.
*/
int
gotoeop(int f, int n)
{
int i;
return(do_gotoeop(f, n, &i));
}
int
do_gotoeop(int f, int n, int *i)
{
int col, nospace, j = 0;
/* the other way... */
if (n < 0)
return (gotobop(f, -n));
/* for each one asked for */
while (n-- > 0) {
*i = ++j;
nospace = 0;
while (lforw(curwp->w_dotp) != curbp->b_headp) {
col = 0;
curwp->w_doto = 0;
while (col < llength(curwp->w_dotp) &&
(isspace(lgetc(curwp->w_dotp, col))))
col++;
if (col >= llength(curwp->w_dotp)) {
if (nospace)
break;
} else
nospace = 1;
curwp->w_dotp = lforw(curwp->w_dotp);
curwp->w_dotline++;
}
}
/* do not continue after end of buffer */
if (lforw(curwp->w_dotp) == curbp->b_headp) {
gotoeol(FFRAND, 1);
curwp->w_rflag |= WFMOVE;
return (FALSE);
}
/* force screen update */
curwp->w_rflag |= WFMOVE;
return (TRUE);
}
/*
* Justify a paragraph. Fill the current paragraph according to the current
* fill column.
*/
int
fillpara(int f, int n)
{
int c; /* current char during scan */
int wordlen; /* length of current word */
int clength; /* position on line during fill */
int i; /* index during word copy */
int eopflag; /* Are we at the End-Of-Paragraph? */
int firstflag; /* first word? (needs no space) */
int newlength; /* tentative new line length */
int eolflag; /* was at end of line */
int retval; /* return value */
struct line *eopline; /* pointer to line just past EOP */
char wbuf[MAXWORD]; /* buffer for current word */
if (n == 0)
return (TRUE);
undo_boundary_enable(FFRAND, 0);
/* record the pointer to the line just past the EOP */
(void)gotoeop(FFRAND, 1);
if (curwp->w_doto != 0) {
/* paragraph ends at end of buffer */
(void)lnewline();
eopline = lforw(curwp->w_dotp);
} else
eopline = curwp->w_dotp;
/* and back top the beginning of the paragraph */
(void)gotobop(FFRAND, 1);
/* initialize various info */
while (inword() == 0 && forwchar(FFRAND, 1));
clength = curwp->w_doto;
wordlen = 0;
/* scan through lines, filling words */
firstflag = TRUE;
eopflag = FALSE;
while (!eopflag) {
/* get the next character in the paragraph */
if ((eolflag = (curwp->w_doto == llength(curwp->w_dotp)))) {
c = ' ';
if (lforw(curwp->w_dotp) == eopline)
eopflag = TRUE;
} else
c = lgetc(curwp->w_dotp, curwp->w_doto);
/* and then delete it */
if (ldelete((RSIZE) 1, KNONE) == FALSE && !eopflag) {
retval = FALSE;
goto cleanup;
}
/* if not a separator, just add it in */
if (c != ' ' && c != '\t') {
if (wordlen < MAXWORD - 1)
wbuf[wordlen++] = c;
else {
/*
* You lose chars beyond MAXWORD if the word
* is too long. I'm too lazy to fix it now; it
* just silently truncated the word before,
* so I get to feel smug.
*/
ewprintf("Word too long!");
}
} else if (wordlen) {
/* calculate tentative new length with word added */
newlength = clength + 1 + wordlen;
/*
* if at end of line or at doublespace and previous
* character was one of '.','?','!' doublespace here.
* behave the same way if a ')' is preceded by a
* [.?!] and followed by a doublespace.
*/
if (dblspace && (!eopflag && ((eolflag ||
curwp->w_doto == llength(curwp->w_dotp) ||
(c = lgetc(curwp->w_dotp, curwp->w_doto)) == ' '
|| c == '\t') && (ISEOSP(wbuf[wordlen - 1]) ||
(wbuf[wordlen - 1] == ')' && wordlen >= 2 &&
ISEOSP(wbuf[wordlen - 2])))) &&
wordlen < MAXWORD - 1))
wbuf[wordlen++] = ' ';
/* at a word break with a word waiting */
if (newlength <= fillcol) {
/* add word to current line */
if (!firstflag) {
(void)linsert(1, ' ');
++clength;
}
firstflag = FALSE;
} else {
if (curwp->w_doto > 0 &&
lgetc(curwp->w_dotp, curwp->w_doto - 1) == ' ') {
curwp->w_doto -= 1;
(void)ldelete((RSIZE) 1, KNONE);
}
/* start a new line */
(void)lnewline();
clength = 0;
}
/* and add the word in in either case */
for (i = 0; i < wordlen; i++) {
(void)linsert(1, wbuf[i]);
++clength;
}
wordlen = 0;
}
}
/* and add a last newline for the end of our new paragraph */
(void)lnewline();
/*
* We really should wind up where we started, (which is hard to keep
* track of) but I think the end of the last line is better than the
* beginning of the blank line.
*/
(void)backchar(FFRAND, 1);
retval = TRUE;
cleanup:
undo_boundary_enable(FFRAND, 1);
return (retval);
}
/*
* Delete n paragraphs. Move to the beginning of the current paragraph, or if
* the cursor is on an empty line, move down the buffer to the first line with
* non-space characters. Then mark n paragraphs and delete.
*/
int
killpara(int f, int n)
{
int lineno, status;
if (n == 0)
return (TRUE);
if (findpara() == FALSE)
return (TRUE);
/* go to the beginning of the paragraph */
(void)gotobop(FFRAND, 1);
/* take a note of the line number for after deletions and set mark */
lineno = curwp->w_dotline;
curwp->w_markp = curwp->w_dotp;
curwp->w_marko = curwp->w_doto;
(void)gotoeop(FFRAND, n);
if ((status = killregion(FFRAND, 1)) != TRUE)
return (status);
curwp->w_dotline = lineno;
return (TRUE);
}
/*
* Mark n paragraphs starting with the n'th and working our way backwards.
* This leaves the cursor at the beginning of the paragraph where markpara()
* was invoked.
*/
int
markpara(int f, int n)
{
int i = 0;
if (n == 0)
return (TRUE);
clearmark(FFARG, 0);
if (findpara() == FALSE)
return (TRUE);
(void)do_gotoeop(FFRAND, n, &i);
/* set the mark here */
curwp->w_markp = curwp->w_dotp;
curwp->w_marko = curwp->w_doto;
(void)gotobop(FFRAND, i);
return (TRUE);
}
/*
* Transpose the current paragraph with the following paragraph. If invoked
* multiple times, transpose to the n'th paragraph. If invoked between
* paragraphs, move to the previous paragraph, then continue.
*/
int
transposepara(int f, int n)
{
int i = 0, status;
char flg;
if (n == 0)
return (TRUE);
undo_boundary_enable(FFRAND, 0);
/* find a paragraph, set mark, then goto the end */
gotobop(FFRAND, 1);
curwp->w_markp = curwp->w_dotp;
curwp->w_marko = curwp->w_doto;
(void)gotoeop(FFRAND, 1);
/* take a note of buffer flags - we may need them */
flg = curbp->b_flag;
/* clean out kill buffer then kill region */
kdelete();
if ((status = killregion(FFRAND, 1)) != TRUE)
return (status);
/*
* Now step through n paragraphs. If we reach the end of buffer,
* stop and paste the killed region back, then display a message.
*/
if (do_gotoeop(FFRAND, n, &i) == FALSE) {
ewprintf("Cannot transpose paragraph, end of buffer reached.");
(void)gotobop(FFRAND, i);
(void)yank(FFRAND, 1);
curbp->b_flag = flg;
return (FALSE);
}
(void)yank(FFRAND, 1);
undo_boundary_enable(FFRAND, 1);
return (TRUE);
}
/*
* Go down the buffer until we find a line with non-space characters.
*/
int
findpara(void)
{
int col, nospace = 0;
/* we move forward to find a para to mark */
do {
curwp->w_doto = 0;
col = 0;
/* check if we are on a blank line */
while (col < llength(curwp->w_dotp)) {
if (!isspace(lgetc(curwp->w_dotp, col)))
nospace = 1;
col++;
}
if (nospace)
break;
if (lforw(curwp->w_dotp) == curbp->b_headp)
return (FALSE);
curwp->w_dotp = lforw(curwp->w_dotp);
curwp->w_dotline++;
} while (1);
return (TRUE);
}
/*
* Insert char with work wrap. Check to see if we're past fillcol, and if so,
* justify this line. As a last step, justify the line.
*/
int
fillword(int f, int n)
{
char c;
int col, i, nce;
for (i = col = 0; col <= fillcol; ++i, ++col) {
if (i == curwp->w_doto)
return selfinsert(f, n);
c = lgetc(curwp->w_dotp, i);
if (c == '\t')
col = ntabstop(col, curwp->w_bufp->b_tabw);
else if (ISCTRL(c) != FALSE)
++col;
}
if (curwp->w_doto != llength(curwp->w_dotp)) {
(void)selfinsert(f, n);
nce = llength(curwp->w_dotp) - curwp->w_doto;
} else
nce = 0;
curwp->w_doto = i;
if ((c = lgetc(curwp->w_dotp, curwp->w_doto)) != ' ' && c != '\t')
do {
(void)backchar(FFRAND, 1);
} while ((c = lgetc(curwp->w_dotp, curwp->w_doto)) != ' ' &&
c != '\t' && curwp->w_doto > 0);
if (curwp->w_doto == 0)
do {
(void)forwchar(FFRAND, 1);
} while ((c = lgetc(curwp->w_dotp, curwp->w_doto)) != ' ' &&
c != '\t' && curwp->w_doto < llength(curwp->w_dotp));
(void)delwhite(FFRAND, 1);
(void)lnewline();
i = llength(curwp->w_dotp) - nce;
curwp->w_doto = i > 0 ? i : 0;
curwp->w_rflag |= WFMOVE;
if (nce == 0 && curwp->w_doto != 0)
return (fillword(f, n));
return (TRUE);
}
/*
* Set fill column to n for justify.
*/
int
setfillcol(int f, int n)
{
char buf[32], *rep;
const char *es;
int nfill;
if ((f & FFARG) != 0) {
fillcol = n;
} else {
if ((rep = eread("Set fill-column: ", buf, sizeof(buf),
EFNEW | EFCR)) == NULL)
return (ABORT);
else if (rep[0] == '\0')
return (FALSE);
nfill = strtonum(rep, 0, INT_MAX, &es);
if (es != NULL) {
dobeep();
ewprintf("Invalid fill column: %s", rep);
return (FALSE);
}
fillcol = nfill;
ewprintf("Fill column set to %d", fillcol);
}
return (TRUE);
}
int
sentencespace(int f, int n)
{
if (f & FFARG)
dblspace = n > 1;
else
dblspace = !dblspace;
return (TRUE);
}