package org.antlr.codegen;
import java.util.*;
public class JavaScriptTarget extends Target {
/** Convert an int to a JavaScript Unicode character literal.
*
* The current JavaScript spec (ECMA-262) doesn't provide for octal
* notation in String literals, although some implementations support it.
* This method overrides the parent class so that characters will always
* be encoded as Unicode literals (e.g. \u0011).
*/
public String encodeIntAsCharEscape(int v) {
String hex = Integer.toHexString(v|0x10000).substring(1,5);
return "\\u"+hex;
}
/** Convert long to two 32-bit numbers separted by a comma.
* JavaScript does not support 64-bit numbers, so we need to break
* the number into two 32-bit literals to give to the Bit. A number like
* 0xHHHHHHHHLLLLLLLL is broken into the following string:
* "0xLLLLLLLL, 0xHHHHHHHH"
* Note that the low order bits are first, followed by the high order bits.
* This is to match how the BitSet constructor works, where the bits are
* passed in in 32-bit chunks with low-order bits coming first.
*
* Note: stole the following two methods from the ActionScript target.
*/
public String getTarget64BitStringFromValue(long word) {
StringBuffer buf = new StringBuffer(22); // enough for the two "0x", "," and " "
buf.append("0x");
writeHexWithPadding(buf, Integer.toHexString((int)(word & 0x00000000ffffffffL)));
buf.append(", 0x");
writeHexWithPadding(buf, Integer.toHexString((int)(word >> 32)));
return buf.toString();
}
private void writeHexWithPadding(StringBuffer buf, String digits) {
digits = digits.toUpperCase();
int padding = 8 - digits.length();
// pad left with zeros
for (int i=1; i<=padding; i++) {
buf.append('0');
}
buf.append(digits);
}
}