persistence.antlr.ANTLRHashString Maven / Gradle / Ivy
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package persistence.antlr;
/* ANTLR Translator Generator
* Project led by Terence Parr at http://www.jGuru.com
* Software rights: http://www.antlr.org/license.html
*
* $Id: ANTLRHashString.java,v 1.1 2006/02/08 21:30:32 tware Exp $
*/
// class implements a String-like object whose sole purpose is to be
// entered into a lexer HashTable. It uses a lexer object to get
// information about case sensitivity.
public class ANTLRHashString {
// only one of s or buf is non-null
private String s;
private char[] buf;
private int len;
private CharScanner lexer;
private static final int prime = 151;
public ANTLRHashString(char[] buf, int length, CharScanner lexer) {
this.lexer = lexer;
setBuffer(buf, length);
}
// Hash strings constructed this way are unusable until setBuffer or setString are called.
public ANTLRHashString(CharScanner lexer) {
this.lexer = lexer;
}
public ANTLRHashString(String s, CharScanner lexer) {
this.lexer = lexer;
setString(s);
}
private final char charAt(int index) {
return (s != null) ? s.charAt(index) : buf[index];
}
// Return true if o is an ANTLRHashString equal to this.
public boolean equals(Object o) {
if (!(o instanceof ANTLRHashString) && !(o instanceof String)) {
return false;
}
ANTLRHashString s;
if (o instanceof String) {
s = new ANTLRHashString((String)o, lexer);
}
else {
s = (ANTLRHashString)o;
}
int l = length();
if (s.length() != l) {
return false;
}
if (lexer.getCaseSensitiveLiterals()) {
for (int i = 0; i < l; i++) {
if (charAt(i) != s.charAt(i)) {
return false;
}
}
}
else {
for (int i = 0; i < l; i++) {
if (lexer.toLower(charAt(i)) != lexer.toLower(s.charAt(i))) {
return false;
}
}
}
return true;
}
public int hashCode() {
int hashval = 0;
int l = length();
if (lexer.getCaseSensitiveLiterals()) {
for (int i = 0; i < l; i++) {
hashval = hashval * prime + charAt(i);
}
}
else {
for (int i = 0; i < l; i++) {
hashval = hashval * prime + lexer.toLower(charAt(i));
}
}
return hashval;
}
private final int length() {
return (s != null) ? s.length() : len;
}
public void setBuffer(char[] buf, int length) {
this.buf = buf;
this.len = length;
s = null;
}
public void setString(String s) {
this.s = s;
buf = null;
}
}