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/* |
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* Copyright (C) 1984-2012 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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|
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/* |
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* Routines to perform bracket matching functions. |
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*/ |
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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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/* |
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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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register int obrac; |
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register int cbrac; |
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int forwdir; |
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int n; |
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{ |
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register int c; |
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register int nest; |
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POSITION pos; |
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int (*chget)(); |
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|
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extern int ch_forw_get(), ch_back_get(); |
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|
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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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/* |
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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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/* |
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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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/* |
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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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} |
