gno/bin/vi/linefunc.c

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/*
* STEVIE - Simply Try this Editor for VI Enthusiasts
*
* Code Contributions By : Tim Thompson twitch!tjt
* Tony Andrews onecom!wldrdg!tony
* G. R. (Fred) Walter watmath!grwalter
*/
#include "stevie.h"
/*
* nextline(curr)
*
* Return a pointer to the beginning of the next line after the one referenced
* by 'curr'. Return NULL if there is no next line (at EOF).
*/
LPtr *
nextline(LPtr *curr)
{
static LPtr next;
if (curr != NULL) {
if (curr->linep->next != Fileend->linep) {
next.index = 0;
next.linep = curr->linep->next;
return &next;
}
}
return (LPtr *) NULL;
}
/*
* prevline(curr)
*
* Return a pointer to the beginning of the line before the one referenced by
* 'curr'. Return NULL if there is no prior line.
*/
LPtr *
prevline(LPtr *curr)
{
static LPtr prev;
if (curr != NULL) {
if (curr->linep->prev != Filetop->linep) {
prev.index = 0;
prev.linep = curr->linep->prev;
return &prev;
}
}
return (LPtr *) NULL;
}
/*
* coladvance(p,col)
*
* Try to advance to the specified column, starting at p.
*/
void
coladvance(LPtr *p, int want_col)
{
register char c;
register int col;
register int incr;
if (gchar(p) != NUL) { /* already at the end of line */
for (col = 0; want_col > 0;) {
c = gchar(p);
if (c == TAB && !P(P_LS))
incr = (P(P_TS) - col % P(P_TS));
else
incr = chars[c].ch_size;
want_col -= incr;
col += incr;
/* Don't go past the end of the file or the line. */
if (inc(p)) {
dec(p);
break;
}
}
}
}