DEC = iota;
NOT = iota;
- OR = iota;
- BOR = iota;
AND = iota;
- BAND = iota;
+ OR = iota;
+ XOR = iota;
ADD = iota;
SUB = iota;
LEQ = iota;
GTR = iota;
GEQ = iota;
+
+ SHL = iota;
+ SHR = iota;
+
+ ADD_ASSIGN = iota;
+ SUB_ASSIGN = iota;
+ MUL_ASSIGN = iota;
+ QUO_ASSIGN = iota;
+ REM_ASSIGN = iota;
+
+ AND_ASSIGN = iota;
+ OR_ASSIGN = iota;
+ XOR_ASSIGN = iota;
+
+ SHL_ASSIGN = iota;
+ SHR_ASSIGN = iota;
+
+ CAND = iota;
+ COR = iota;
// keywords
BREAK = iota;
case INC: return "INC";
case DEC: return "DEC";
case NOT: return "NOT";
-
- case OR: return "OR";
- case BOR: return "BOR";
+
case AND: return "AND";
- case BAND: return "BAND";
+ case OR: return "OR";
+ case XOR: return "XOR";
case ADD: return "ADD";
case SUB: return "SUB";
case GTR: return "GTR";
case GEQ: return "GEQ";
+ case SHL: return SHL;
+ case SHR: return SHR;
+
+ case ADD_ASSIGN: return "ADD_ASSIGN";
+ case SUB_ASSIGN: return "SUB_ASSIGN";
+ case MUL_ASSIGN: return "MUL_ASSIGN";
+ case QUO_ASSIGN: return "QUO_ASSIGN";
+ case REM_ASSIGN: return "REM_ASSIGN";
+
+ case AND_ASSIGN: return "AND_ASSIGN";
+ case OR_ASSIGN: return "OR_ASSIGN";
+ case XOR_ASSIGN: return "XOR_ASSIGN";
+
+ case SHL_ASSIGN: return "SHL_ASSIGN";
+ case SHR_ASSIGN: return "SHR_ASSIGN";
+
+ case CAND: return "CAND";
+ case COR: return "COR";
+
case BREAK: return "BREAK";
case CASE: return "CASE";
case CONST: return "CONST";
}
-func (S *Scanner) ScanNumber () {
+func (S *Scanner) ScanMantissa () {
+ for is_dec_digit(S.ch) {
+ S.Next();
+ }
+}
+
+
+func (S *Scanner) ScanNumber () int {
// TODO complete this routine
-
- for is_dec_digit(S.ch) {
- S.Next();
+ if S.ch == '.' {
+ S.Next();
+ }
+ S.ScanMantissa();
+ if S.ch == 'e' || S.ch == 'E' {
+ S.Next();
+ if S.ch == '-' || S.ch == '+' {
+ S.Next();
+ }
+ S.ScanMantissa();
}
+ return NUMBER;
}
}
-func (S *Scanner) ScanChar () {
- S.Next(); // consume '\'
-
+func (S *Scanner) ScanChar () int {
if (S.ch == '\\') {
S.Next();
S.ScanEscape();
} else {
panic "char not terminated";
}
+ return NUMBER;
}
-func (S *Scanner) ScanString () {
- for S.Next(); S.ch != '"'; S.Next() {
+func (S *Scanner) ScanString () int {
+ for ; S.ch != '"'; S.Next() {
if S.ch == '\n' || S.ch < 0 {
panic "string not terminated";
}
}
S.Next();
+ return STRING;
}
-func (S *Scanner) ScanRawString () {
- for S.Next(); S.ch != '`'; S.Next() {
+func (S *Scanner) ScanRawString () int {
+ for ; S.ch != '`'; S.Next() {
if S.ch == '\n' || S.ch < 0 {
panic "string not terminated";
}
}
S.Next();
+ return STRING;
+}
+
+
+func (S *Scanner) Select2 (tok0, tok1 int) int {
+ if S.ch == '=' {
+ S.Next();
+ return tok1;
+ }
+ return tok0;
+}
+
+
+func (S *Scanner) Select3 (tok0, tok1, ch2, tok2 int) int {
+ if S.ch == '=' {
+ S.Next();
+ return tok1;
+ }
+ if S.ch == ch2 {
+ S.Next();
+ return tok2;
+ }
+ return tok0;
+}
+
+
+func (S *Scanner) Select4 (tok0, tok1, ch2, tok2, tok3 int) int {
+ if S.ch == '=' {
+ S.Next();
+ return tok1;
+ }
+ if S.ch == ch2 {
+ S.Next();
+ if S.ch == '=' {
+ S.Next();
+ return tok3;
+ }
+ return tok2;
+ }
+ return tok0;
}
var beg int = S.pos - 1;
var end int = beg;
- if is_letter(S.ch) {
- tok = S.ScanIdentifier();
-
- } else if is_dec_digit(S.ch) {
- S.ScanNumber();
- tok = NUMBER;
-
- } else {
- switch S.ch {
- case -1:
- tok = EOF;
-
+ switch ch := S.ch; {
+ case is_letter(ch): tok = S.ScanIdentifier();
+ case is_dec_digit(ch): tok = S.ScanNumber();
+ default:
+ S.Next();
+ switch ch {
+ case -1: tok = EOF;
+ case '"': tok = S.ScanString();
+ case '\'': tok = S.ScanChar();
+ case '`': tok = S.ScanRawString();
+ case ':': tok = S.Select2(COLON, DEFINE);
+ case '.':
+ if is_dec_digit(S.ch) {
+ tok = S.ScanNumber();
+ } else {
+ tok = PERIOD;
+ }
+ case ',': tok = COMMA;
+ case ';': tok = SEMICOLON;
+ case '(': tok = LPAREN;
+ case ')': tok = RPAREN;
+ case '[': tok = LBRACK;
+ case ']': tok = RBRACK;
+ case '{': tok = LBRACE;
+ case '}': tok = RBRACE;
+ case '+': tok = S.Select3(ADD, ADD_ASSIGN, '+', INC);
+ case '-': tok = S.Select3(SUB, SUB_ASSIGN, '-', DEC);
+ case '*': tok = S.Select2(MUL, MUL_ASSIGN);
case '/':
- S.Next();
if S.ch == '/' || S.ch == '*' {
S.SkipComment();
+ // cannot simply return because of 6g bug
tok, beg, end = S.Scan();
return tok, beg, end;
- } else {
- tok = QUO;
- }
-
- case '"':
- S.ScanString();
- tok = STRING;
-
- case '\'':
- S.ScanChar();
- tok = NUMBER;
-
- case '`':
- S.ScanRawString();
- tok = STRING;
-
- case ':':
- S.Next();
- if (S.ch == '=') {
- S.Next();
- tok = DEFINE;
- } else {
- tok = COLON;
- }
-
- case '.':
- S.Next();
- tok = PERIOD;
-
- case ',':
- S.Next();
- tok = COMMA;
-
- case '+':
- S.Next();
- if (S.ch == '+') {
- S.Next();
- tok = INC;
- } else {
- tok = ADD;
}
-
- case '-':
- S.Next();
- if (S.ch == '-') {
- S.Next();
- tok = DEC;
- } else {
- tok = SUB;
- }
-
- case '*':
- S.Next();
- tok = MUL;
+ tok = S.Select2(QUO, QUO_ASSIGN);
+ case '%': tok = S.Select2(REM, REM_ASSIGN);
+ case '^': tok = S.Select2(XOR, XOR_ASSIGN);
+ case '<': tok = S.Select4(LSS, LEQ, '<', SHL, SHL_ASSIGN);
+ case '>': tok = S.Select4(GTR, GEQ, '>', SHR, SHR_ASSIGN);
+ case '=': tok = S.Select2(ASSIGN, EQL);
+ case '!': tok = S.Select2(NOT, NEQ);
+ case '&': tok = S.Select3(AND, AND_ASSIGN, '&', CAND);
+ case '|': tok = S.Select3(OR, OR_ASSIGN, '|', COR);
+ default: tok = ILLEGAL;
- case '/':
- S.Next();
- tok = QUO;
-
- case '%':
- S.Next();
- tok = REM;
-
- case '<':
- S.Next();
- if (S.ch == '=') {
- S.Next();
- tok = LEQ;
- } else {
- tok = LSS;
- }
-
- case '>':
- S.Next();
- if (S.ch == '=') {
- S.Next();
- tok = GEQ;
- } else {
- tok = GTR;
- }
-
- case '=':
- S.Next();
- if (S.ch == '=') {
- S.Next();
- tok = EQL;
- } else {
- tok = ASSIGN;
- }
-
- case '!':
- S.Next();
- if (S.ch == '=') {
- S.Next();
- tok = NEQ;
- } else {
- tok = NOT;
- }
-
- case ';':
- S.Next();
- tok = SEMICOLON;
-
- case '(':
- S.Next();
- tok = LPAREN;
-
- case ')':
- S.Next();
- tok = LPAREN;
-
- case '[':
- S.Next();
- tok = LBRACK;
-
- case ']':
- S.Next();
- tok = RBRACK;
-
- case '{':
- S.Next();
- tok = LBRACE;
-
- case '}':
- S.Next();
- tok = RBRACE;
-
- case '&':
- S.Next();
- if S.ch == '&' {
- S.Next();
- tok = AND;
- } else {
- tok = BAND;
- }
-
- case '|':
- S.Next();
- if S.ch == '|' {
- S.Next();
- tok = OR;
- } else {
- tok = BOR;
- }
-
- default:
- S.Next(); // make progress
}
}