101 lines
2.2 KiB
C
101 lines
2.2 KiB
C
/*
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* Copyright (C) 1984-2017 Mark Nudelman
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*
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* You may distribute under the terms of either the GNU General Public
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* License or the Less License, as specified in the README file.
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*
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* For more information, see the README file.
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*/
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/*
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* Routines to perform bracket matching functions.
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*/
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#include "less.h"
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#include "position.h"
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/*
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* Try to match the n-th open bracket
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* which appears in the top displayed line (forwdir),
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* or the n-th close bracket
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* which appears in the bottom displayed line (!forwdir).
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* The characters which serve as "open bracket" and
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* "close bracket" are given.
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*/
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public void
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match_brac(obrac, cbrac, forwdir, n)
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int obrac;
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int cbrac;
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int forwdir;
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int n;
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{
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int c;
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int nest;
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POSITION pos;
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int (*chget)();
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extern int ch_forw_get(), ch_back_get();
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/*
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* Seek to the line containing the open bracket.
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* This is either the top or bottom line on the screen,
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* depending on the type of bracket.
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*/
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pos = position((forwdir) ? TOP : BOTTOM);
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if (pos == NULL_POSITION || ch_seek(pos))
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{
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if (forwdir)
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error("Nothing in top line", NULL_PARG);
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else
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error("Nothing in bottom line", NULL_PARG);
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return;
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}
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/*
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* Look thru the line to find the open bracket to match.
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*/
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do
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{
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if ((c = ch_forw_get()) == '\n' || c == EOI)
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{
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if (forwdir)
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error("No bracket in top line", NULL_PARG);
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else
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error("No bracket in bottom line", NULL_PARG);
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return;
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}
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} while (c != obrac || --n > 0);
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/*
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* Position the file just "after" the open bracket
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* (in the direction in which we will be searching).
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* If searching forward, we are already after the bracket.
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* If searching backward, skip back over the open bracket.
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*/
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if (!forwdir)
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(void) ch_back_get();
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/*
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* Search the file for the matching bracket.
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*/
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chget = (forwdir) ? ch_forw_get : ch_back_get;
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nest = 0;
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while ((c = (*chget)()) != EOI)
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{
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if (c == obrac)
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nest++;
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else if (c == cbrac && --nest < 0)
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{
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/*
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* Found the matching bracket.
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* If searching backward, put it on the top line.
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* If searching forward, put it on the bottom line.
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*/
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jump_line_loc(ch_tell(), forwdir ? -1 : 1);
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return;
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}
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}
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error("No matching bracket", NULL_PARG);
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}
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