/**
* Copyright (C) 2001-2017 by RapidMiner and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapidminer.com
*
* This program is free software: you can redistribute it and/or modify it under the terms of the
* GNU Affero General Public License as published by the Free Software Foundation, either version 3
* 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
* Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License along with this program.
* If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.gui.tools.syntax;
/*
* TeXTokenMarker.java - TeX/LaTeX/AMS-TeX token marker Copyright (C) 1998 Slava Pestov
*
* You may use and modify this package for any purpose. Redistribution is permitted, in both source
* and binary form, provided that this notice remains intact in all source distributions of this
* package.
*/
import javax.swing.text.Segment;
/**
* TeX token marker.
*
* @author Slava Pestov, Ingo Mierswa
*/
public class TeXTokenMarker extends TokenMarker {
// public members
public static final byte BDFORMULA = Token.INTERNAL_FIRST;
public static final byte EDFORMULA = (byte) (Token.INTERNAL_FIRST + 1);
@Override
public byte markTokensImpl(byte token, Segment line, int lineIndex) {
char[] array = line.array;
int offset = line.offset;
int lastOffset = offset;
int length = line.count + offset;
boolean backslash = false;
loop: for (int i = offset; i < length; i++) {
int i1 = (i + 1);
char c = array[i];
// if a backslash is followed immediately
// by a non-alpha character, the command at
// the non-alpha char. If we have a backslash,
// some text, and then a non-alpha char,
// the command ends before the non-alpha char.
if (Character.isLetter(c)) {
backslash = false;
} else {
if (backslash) {
// \<non alpha>
// we skip over this character,
// hence the `continue'
backslash = false;
if (token == Token.KEYWORD2 || token == EDFORMULA) {
token = Token.KEYWORD2;
}
addToken(i1 - lastOffset, token);
lastOffset = i1;
if (token == Token.KEYWORD1) {
token = Token.NULL;
}
continue;
} else {
// \blah<non alpha>
// we leave the character in
// the stream, and it's not
// part of the command token
if (token == BDFORMULA || token == EDFORMULA) {
token = Token.KEYWORD2;
}
addToken(i - lastOffset, token);
if (token == Token.KEYWORD1) {
token = Token.NULL;
}
lastOffset = i;
}
}
switch (c) {
case '%':
if (backslash) {
backslash = false;
break;
}
addToken(i - lastOffset, token);
addToken(length - i, Token.COMMENT1);
lastOffset = length;
break loop;
case '\\':
backslash = true;
if (token == Token.NULL) {
token = Token.KEYWORD1;
addToken(i - lastOffset, Token.NULL);
lastOffset = i;
}
break;
case '$':
backslash = false;
if (token == Token.NULL) // singe $
{
token = Token.KEYWORD2;
addToken(i - lastOffset, Token.NULL);
lastOffset = i;
} else if (token == Token.KEYWORD1) // \...$
{
token = Token.KEYWORD2;
addToken(i - lastOffset, Token.KEYWORD1);
lastOffset = i;
} else if (token == Token.KEYWORD2) // $$aaa
{
if (i - lastOffset == 1 && array[i - 1] == '$') {
token = BDFORMULA;
break;
}
token = Token.NULL;
addToken(i1 - lastOffset, Token.KEYWORD2);
lastOffset = i1;
} else if (token == BDFORMULA) // $$aaa$
{
token = EDFORMULA;
} else if (token == EDFORMULA) // $$aaa$$
{
token = Token.NULL;
addToken(i1 - lastOffset, Token.KEYWORD2);
lastOffset = i1;
}
break;
}
}
if (lastOffset != length) {
addToken(length - lastOffset, token == BDFORMULA || token == EDFORMULA ? Token.KEYWORD2 : token);
}
return (token != Token.KEYWORD1 ? token : Token.NULL);
}
}