/*
** OPERATOR -- process a token starting with an operator
**
** Processes operators, strings, comments, and
** floating constants without a leading 0.
**
** Parameters:
** chr - first character of token {equel_cmap (chr) == OPATR}
**
** Returns:
** NUMBER or STRING token, or operator token.
** CONTINUE on error.
**
** Side Effects:
** Adds a node to the Symbol space, and returns adress
** in "yylval".
** Opcode is set to the opcode of the operator.
** May backup a character.
*/
int
operator(char chr)
{
register struct optab *op;
char opbuf [3];
opbuf [0] = chr;
opbuf [1] = getch();
opbuf [2] = '\0';
if (opbuf [0] == '.' && equel_cmap(opbuf[1]) == NUMBR) {
/* floating mantissa w/o leading 0 */
backup(opbuf [1]);
return (number(opbuf [0]));
}
if (equel_cmap(opbuf[1]) != OPATR) {
backup(opbuf [1]);
opbuf [1] = '\0';
}
/* operator has been reduced to its smallest
* possible length, now try to find it in the
* operator table [tokens.y]
*/
for ( ; ; ) {
for (op = Optab; op->op_term; op++)
if (strcmp(op->op_term, opbuf) == 0)
break;
if (!op->op_term && opbuf [1]) {
/* reduce a 2 char operator to 1 char,
* and re-search
*/
backup(opbuf[1]);
opbuf [1] = '\0';
continue;
}
break;
}
if (op->op_term) {
/* string quotes ? */
if (op->op_token == Tokens.sp_quote)
return (string(op));
/* comment indicator ? */
if (op->op_token == Tokens.sp_bgncmnt)
return (comment());
/* {strcmp(opbuf, op->op_term) == 0} */
Opcode = op->op_code;
yylval.u_dn = addsym(op->op_term);
return (op->op_token);
}
yysemerr("bad operator", opbuf);
/* operator not found, skip token and try again */
return (CONTINUE);
}
/*
** COMMENT.C -- routine to scan comments inside an EQL statement
**
** Uses the endcmnt token code to find the endcmnt
** terminal string, then reads the input until it sees this
** terminal (must be <= 2 characters), returning EOF_TOK and
** giving an error diagnostic if end-of-file is encountered.
**
** Returns:
** CONTINUE -- valid comment
** EOF_TOK -- EOF in comment
**
** Side Effects:
** deletes comments from within an EQL statement
**
*/
comment()
{
register int i;
register int l;
register struct optab *op;
char buf[3];
/* find end of comment operator */
for (op = Optab; op->op_term; op++)
if (op->op_token == Tokens.sp_endcmnt)
break;
if (!op->op_term)
AAsyserr(13000);
/* scan for the end of comment */
l = AAlength(op->op_term);
if (l > sizeof buf - 1)
AAsyserr(13001, l, op->op_term, sizeof buf -1);
/* fill buffer to length of endmnt terminal */
for (i = 0; i < l; i++)
{
if ((buf[i] = getch()) == EOF_TOK)
{
nontermcom :
/* non-terminated comment */
yysemerr("premature EOF encountered in comment", (char *) 0);
return (EOF_TOK);
}
}
/* shift on input until endcmnt */
while (!AAbequal(buf, op->op_term, l))
{
for (i = 0; i < l - 1; i++)
buf[i] = buf[i + 1];
if ((buf[l - 1] = getch()) == EOF_TOK)
goto nontermcom;
}
return (CONTINUE);
}
