//
// Advanced the input by one character
//
protected void advance() throws java.io.IOException {
next_char = inp.read();
switch (next_char) {
case -1: // EOF
if (char_num == 0) {
char_num = -1;
break;
}
next_char = '\n';
// pass thru
case '\n': // a new line
line_num++;
char_num = 0;
break;
default:
line.append((char) next_char);
char_num++;
return;
}
line.setLength(0);
}
//
// recognize and return the next complete token
//
public token next_token() throws java.io.IOException, jasError {
token_line_num = line_num;
for (; ; )
switch (next_char) {
case ';': // a comment
case '\n':
// return single SEP token (skip multiple newlines
// interspersed with whitespace or comments)
skip_empty_lines();
token_line_num = line_num;
return new token(sym.SEP);
case -1: // EOF token
char_num = -1;
return new token(sym.EOF);
case '-':
case '+':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
case '.': // a number
{
int pos = 0;
do {
chars[pos] = (char) next_char;
pos++;
if (pos == chars_size) chars_expand();
advance();
} while (!separator(next_char));
String str = new String(chars, 0, pos);
token tok;
// This catches directives like ".method"
if ((tok = ReservedWords.get(str)) != null) return tok;
Number num;
try {
num = ScannerUtils.convertNumber(str);
} catch (NumberFormatException e) {
if (chars[0] != '.') throw new jasError("Badly formatted number");
throw new jasError("Unknown directive or badly formed number.");
}
if (num instanceof Integer) {
int_line = line.toString();
int_line_num = token_line_num;
int_char_num = char_num;
return new int_token(sym.Int, num.intValue());
}
return new num_token(sym.Num, num);
}
case '"': // quoted string
{
boolean already = false;
for (int pos = 0; ; ) {
if (already) already = false;
else advance();
if (next_char == '"') {
advance(); // skip close quote
return new str_token(sym.Str, new String(chars, 0, pos));
}
if (next_char == -1) throw new jasError("Unterminated string");
char chval = (char) next_char;
if (chval == '\\') {
advance();
switch (next_char) {
case -1:
already = true;
continue;
case 'n':
chval = '\n';
break;
case 'r':
chval = '\r';
break;
case 't':
chval = '\t';
break;
case 'f':
chval = '\f';
break;
case 'b':
chval = '\b';
break;
case '"':
chval = '"';
break;
case '\'':
chval = '\'';
break;
case '\\':
chval = '\\';
break;
case 'u':
chval = uniEscape();
if (next_char == -1) {
already = true;
continue;
}
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
{
int res = next_char & 7;
advance();
if (next_char < '0' || next_char > '7') already = true;
else {
res = res * 8 + (next_char & 7);
advance();
if (next_char < '0' || next_char > '7') already = true;
else {
int val = res * 8 + (next_char & 7);
if (val >= 0x100) already = true;
else res = val;
}
}
chval = (char) res;
}
break;
default:
throw new jasError("Bad backslash escape sequence");
}
}
chars[pos] = chval;
pos++;
if (pos == chars_size) chars_expand();
}
}
case '\'': // quotation for overloading reserved words
for (int pos = 0; ; ) {
advance();
if (separator(next_char)) throw new jasError("Unterminated ''-enclosed name");
if (next_char == '\'') {
if (pos == 0) throw new jasError("Empty ''-enclosed name");
advance(); // skip close quote
if (!separator(next_char)) throw new jasError("Not separator after ''-enclosed name");
return new str_token(sym.Word, new String(chars, 0, pos));
}
char chval = (char) next_char;
if (next_char == '\\') chval = nameEscape();
chars[pos] = chval;
pos++;
if (pos == chars_size) chars_expand();
}
case ' ':
case '\t':
case '\r': // whitespace
advance();
break;
case '=': // EQUALS token
advance();
return new token(sym.EQ);
case ':': // COLON token
advance();
return new token(sym.COLON);
default:
{
// read up until a separatorcharacter
int pos = 0;
boolean only_name = false;
do {
char chval = (char) next_char;
if (next_char == '\\') {
chval = nameEscape();
only_name = true;
}
chars[pos] = chval;
pos++;
if (pos == chars_size) chars_expand();
advance();
} while (!separator(next_char));
// convert the byte array into a String
String str = new String(chars, 0, pos);
if (!only_name) {
token tok;
// Jasmin keyword or directive ?
if ((tok = ReservedWords.get(str)) != null) return tok;
// its a JVM instruction ?
if (InsnInfo.contains(str)) return new str_token(sym.Insn, str);
if (str.charAt(0) == '$') {
String s = str.substring(1);
Object v;
int n = 10;
boolean neg = false;
boolean sign = false;
switch (s.charAt(0)) {
default:
break;
case '-':
neg = true;
;
case '+':
s = s.substring(1);
if (s.startsWith("0x")) {
n = 16;
s = s.substring(2);
}
try {
n = Integer.parseInt(s, n);
} catch (NumberFormatException e) {
throw new jasError("Badly relative offset number");
}
if (neg) n = -n;
return new relative_num_token(sym.Relative, n);
}
// Perform variable substitution
if ((v = dict.get(s)) != null) return (token) v;
} // not begin from '$'
} // !only_name
// Unrecognized string token (e.g. a classname)
return new str_token(sym.Word, str);
} /* default */
} /* switch and for */
}
