mirror of https://github.com/tongzx/nt5src
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
165 lines
2.7 KiB
165 lines
2.7 KiB
/* $Header: /nw/tony/src/stevie/src/RCS/ptrfunc.c,v 1.5 89/03/11 22:43:12 tony Exp $
|
|
*
|
|
* The routines in this file attempt to imitate many of the operations
|
|
* that used to be performed on simple character pointers and are now
|
|
* performed on LNPTR's. This makes it easier to modify other sections
|
|
* of the code. Think of an LNPTR as representing a position in the file.
|
|
* Positions can be incremented, decremented, compared, etc. through
|
|
* the functions implemented here.
|
|
*/
|
|
|
|
#include "stevie.h"
|
|
|
|
/*
|
|
* inc(p)
|
|
*
|
|
* Increment the line pointer 'p' crossing line boundaries as necessary.
|
|
* Return 1 when crossing a line, -1 when at end of file, 0 otherwise.
|
|
*/
|
|
int
|
|
inc(lp)
|
|
register LNPTR *lp;
|
|
{
|
|
register char *p;
|
|
|
|
if (lp && lp->linep)
|
|
p = &(lp->linep->s[lp->index]);
|
|
else
|
|
return -1;
|
|
|
|
if (*p != NUL) { /* still within line */
|
|
lp->index++;
|
|
return ((p[1] != NUL) ? 0 : 1);
|
|
}
|
|
|
|
if (lp->linep->next != Fileend->linep) { /* there is a next line */
|
|
lp->index = 0;
|
|
lp->linep = lp->linep->next;
|
|
return 1;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* dec(p)
|
|
*
|
|
* Decrement the line pointer 'p' crossing line boundaries as necessary.
|
|
* Return 1 when crossing a line, -1 when at start of file, 0 otherwise.
|
|
*/
|
|
int
|
|
dec(lp)
|
|
register LNPTR *lp;
|
|
{
|
|
if (lp->index > 0) { /* still within line */
|
|
lp->index--;
|
|
return 0;
|
|
}
|
|
|
|
if (lp->linep &&
|
|
lp->linep->prev != Filetop->linep) { /* there is a prior line */
|
|
lp->linep = lp->linep->prev;
|
|
lp->index = strlen(lp->linep->s);
|
|
return 1;
|
|
}
|
|
|
|
lp->index = 0; /* stick at first char */
|
|
return -1; /* at start of file */
|
|
}
|
|
|
|
/*
|
|
* gchar(lp) - get the character at position "lp"
|
|
*/
|
|
int
|
|
gchar(lp)
|
|
register LNPTR *lp;
|
|
{
|
|
if (lp && lp->linep)
|
|
return (lp->linep->s[lp->index]);
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* pchar(lp, c) - put character 'c' at position 'lp'
|
|
*/
|
|
void
|
|
pchar(lp, c)
|
|
register LNPTR *lp;
|
|
char c;
|
|
{
|
|
lp->linep->s[lp->index] = c;
|
|
}
|
|
|
|
/*
|
|
* pswap(a, b) - swap two position pointers
|
|
*/
|
|
void
|
|
pswap(a, b)
|
|
register LNPTR *a, *b;
|
|
{
|
|
LNPTR tmp;
|
|
|
|
tmp = *a;
|
|
*a = *b;
|
|
*b = tmp;
|
|
}
|
|
|
|
/*
|
|
* Position comparisons
|
|
*/
|
|
|
|
bool_t
|
|
lt(a, b)
|
|
register LNPTR *a, *b;
|
|
{
|
|
register int an, bn;
|
|
|
|
an = LINEOF(a);
|
|
bn = LINEOF(b);
|
|
|
|
if (an != bn)
|
|
return (an < bn);
|
|
else
|
|
return (a->index < b->index);
|
|
}
|
|
|
|
#if 0
|
|
bool_t
|
|
gt(a, b)
|
|
LNPTR *a, *b;
|
|
{
|
|
register int an, bn;
|
|
|
|
an = LINEOF(a);
|
|
bn = LINEOF(b);
|
|
|
|
if (an != bn)
|
|
return (an > bn);
|
|
else
|
|
return (a->index > b->index);
|
|
}
|
|
#endif
|
|
|
|
bool_t
|
|
equal(a, b)
|
|
register LNPTR *a, *b;
|
|
{
|
|
return (a->linep == b->linep && a->index == b->index);
|
|
}
|
|
|
|
bool_t
|
|
ltoreq(a, b)
|
|
register LNPTR *a, *b;
|
|
{
|
|
return (lt(a, b) || equal(a, b));
|
|
}
|
|
|
|
#if 0
|
|
bool_t
|
|
gtoreq(a, b)
|
|
LNPTR *a, *b;
|
|
{
|
|
return (gt(a, b) || equal(a, b));
|
|
}
|
|
#endif
|