/* Copyright (C) 2003-2011 JabRef contributors.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
// $Id$
package net.sf.jabref.bst;
/**
*
* The |built_in| function {\.{purify\$}} pops the top (string) literal, removes
* nonalphanumeric characters except for |white_space| and |sep_char| characters
* (these get converted to a |space|) and removes certain alphabetic characters
* contained in the control sequences associated with a special character, and
* pushes the resulting string. If the literal isn't a string, it complains and
* pushes the null string.
*
* @author $Author$
* @version $Revision$ ($Date$)
*
*/
public class BibtexPurify {
/**
*
* @param toPurify
* @param warn
* may-be-null
* @return
*/
public static String purify(String toPurify, Warn warn) {
StringBuffer sb = new StringBuffer();
char[] cs = toPurify.toCharArray();
int n = cs.length;
int i = 0;
int braceLevel = 0;
while (i < n) {
char c = cs[i];
if (Character.isWhitespace(c) || c == '-' || c == '~') {
sb.append(' ');
} else if (Character.isLetterOrDigit(c)) {
sb.append(c);
} else if (c == '{') {
braceLevel++;
if (braceLevel == 1 && i + 1 < n && (cs[i + 1] == '\\')) {
i++; // skip brace
while (i < n && braceLevel > 0) {
i++; // skip backslash
String specialStart = BibtexCaseChanger.findSpecialChar(cs, i);
if (specialStart != null) {
sb.append(specialStart);
}
while (i < n && Character.isLetter(cs[i])) {
i++;
}
while (i < n && braceLevel > 0 && (c = cs[i]) != '\\') {
if (Character.isLetterOrDigit(c)) {
sb.append(c);
} else if (c == '}') {
braceLevel--;
} else if (c == '{') {
braceLevel++;
}
i++;
}
}
continue;
}
} else if (c == '}') {
if (braceLevel > 0) {
braceLevel--;
} else {
if (warn != null)
warn.warn("Unbalanced brace in string for purify$: " + toPurify);
}
}
i++;
}
if (braceLevel != 0 && warn != null)
warn.warn("Unbalanced brace in string for purify$: " + toPurify);
return sb.toString();
}
}