static arith_t assignment(int var, int noeval)
{
union yystype val = yylval;
int op = yylex();
arith_t result;
char sresult[DIGITS(result) + 1];
if (var != ARITH_VAR)
return cond(var, &val, op, noeval);
if (op != ARITH_ASS && (op < ARITH_ASS_MIN || op >= ARITH_ASS_MAX))
return cond(var, &val, op, noeval);
result = assignment(yylex(), noeval);
if (noeval)
return result;
if (op != ARITH_ASS)
result = do_binop(op - 11, arith_lookupvarint(val.name), result);
snprintf(sresult, sizeof(sresult), ARITH_FORMAT_STR, result);
setvar(val.name, sresult, 0);
return result;
}
static arith_t
primary(int token, union yystype *val, int op, int noeval)
{
arith_t result;
again:
switch (token) {
case ARITH_LPAREN:
result = assignment(op, noeval);
if (last_token != ARITH_RPAREN)
yyerror("expecting ')'");
last_token = yylex();
return result;
case ARITH_NUM:
last_token = op;
return val->val;
case ARITH_VAR:
last_token = op;
return noeval ? val->val : arith_lookupvarint(val->name);
case ARITH_ADD:
token = op;
*val = yylval;
op = yylex();
goto again;
case ARITH_SUB:
*val = yylval;
return -primary(op, val, yylex(), noeval);
case ARITH_NOT:
*val = yylval;
return !primary(op, val, yylex(), noeval);
case ARITH_BNOT:
*val = yylval;
return ~primary(op, val, yylex(), noeval);
default:
yyerror("expecting primary");
}
}
