87 lines
2 KiB
C
87 lines
2 KiB
C
/* $Header: /nw/tony/src/stevie/src/RCS/linefunc.c,v 1.2 89/03/11 22:42:32 tony Exp $
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*
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* Basic line-oriented motions.
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*/
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#include "stevie.h"
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/*
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* nextline(curr)
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*
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* Return a pointer to the beginning of the next line after the one
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* referenced by 'curr'. Return NULL if there is no next line (at EOF).
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*/
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LNPTR *
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nextline(curr)
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LNPTR *curr;
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{
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static LNPTR next;
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if (curr->linep && curr->linep->next != Fileend->linep) {
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next.index = 0;
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next.linep = curr->linep->next;
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return &next;
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}
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return (LNPTR *) NULL;
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}
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/*
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* prevline(curr)
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*
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* Return a pointer to the beginning of the line before the one
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* referenced by 'curr'. Return NULL if there is no prior line.
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*/
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LNPTR *
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prevline(curr)
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LNPTR *curr;
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{
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static LNPTR prev;
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if (curr->linep->prev != Filetop->linep) {
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prev.index = 0;
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prev.linep = curr->linep->prev;
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return &prev;
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}
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return (LNPTR *) NULL;
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}
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/*
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* coladvance(p,col)
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*
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* Try to advance to the specified column, starting at p.
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*/
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LNPTR *
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coladvance(p, col)
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LNPTR *p;
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register int col;
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{
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static LNPTR lp;
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register int c, in;
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lp.linep = p->linep;
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lp.index = p->index;
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/* If we're on a blank ('\n' only) line, we can't do anything */
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if (lp.linep->s[lp.index] == '\0')
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return &lp;
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/* try to advance to the specified column */
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for ( c=0; col-- > 0; c++ ) {
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/* Count a tab for what it's worth (if list mode not on) */
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if ( gchar(&lp) == TAB && !P(P_LS) ) {
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in = ((P(P_TS)-1) - c%P(P_TS));
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col -= in;
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c += in;
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}
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/* Don't go past the end of */
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/* the file or the line. */
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if (inc(&lp)) {
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dec(&lp);
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break;
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}
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}
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return &lp;
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}
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