src/main/java/org/luaj/vm3/ast/Str.java

/*******************************************************************************
* Copyright (c) 2010 Luaj.org. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* 
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
******************************************************************************/
package org.luaj.vm3.ast;

import java.io.ByteArrayOutputStream;
import java.io.UnsupportedEncodingException;

import org.luaj.vm3.LuaString;

public class Str {

	private Str() {}

	public static LuaString quoteString(String image) {
		String s = image.substring(1, image.length() - 1);
		byte[] bytes = unquote(s);
		return LuaString.valueOf(bytes);
	}

	public static LuaString charString(String image) {
		String s = image.substring(1, image.length() - 1);
		byte[] bytes = unquote(s);
		return LuaString.valueOf(bytes);
	}

	public static LuaString longString(String image) {
		int i = image.indexOf('[', image.indexOf('[') + 1) + 1;
		String s = image.substring(i, image.length() - i);
		byte[] b = iso88591bytes(s);
		return LuaString.valueOf(b);
	}

	public static byte[] iso88591bytes(String s) {
		try {
			return s.getBytes("ISO8859-1");
		} catch (UnsupportedEncodingException e) {
			throw new IllegalStateException("ISO8859-1 not supported");
		}
	}

	public static byte[] unquote(String s) {
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		char[] c = s.toCharArray();
		int n = c.length;
		for (int i = 0; i < n; i++) {
			if (c[i] == '\\' && i < n) {
				switch (c[++i]) {
				case '0':
				case '1':
				case '2':
				case '3':
				case '4':
				case '5':
				case '6':
				case '7':
				case '8':
				case '9':
					int d = (int) (c[i++] - '0');
					for (int j = 0; i < n && j < 2 && c[i] >= '0' && c[i] <= '9'; i++, j++)
						d = d * 10 + (int) (c[i] - '0');
					baos.write((byte) d);
					--i;
					continue;
				case 'a':
					baos.write((byte) 7);
					continue;
				case 'b':
					baos.write((byte) '\b');
					continue;
				case 'f':
					baos.write((byte) '\f');
					continue;
				case 'n':
					baos.write((byte) '\n');
					continue;
				case 'r':
					baos.write((byte) '\r');
					continue;
				case 't':
					baos.write((byte) '\t');
					continue;
				case 'v':
					baos.write((byte) 11);
					continue;
				case '"':
					baos.write((byte) '"');
					continue;
				case '\'':
					baos.write((byte) '\'');
					continue;
				case '\\':
					baos.write((byte) '\\');
					continue;
				default:
					baos.write((byte) c[i]);
					break;
				}
			} else {
				baos.write((byte) c[i]);
			}
		}
		return baos.toByteArray();
	}
}