/* single - handle a single action */
int single(void)
{
/* execute the before code */
switch (execute(h_before)) {
case ABORT: /* before handler aborted sequence */
return (FALSE);
case CHAIN: /* execute the action handler */
if (execute(getafield(getvalue(V_ACTION),A_CODE)) == ABORT)
return (FALSE);
case FINISH:/* execute the after code */
if (execute(h_after) == ABORT)
return (FALSE);
break;
}
return (TRUE);
}
/* hasverb - check to see if this action has this verb */
int hasverb(int act,int *verbs)
{
int link,word,*verb;
/* get the list of verbs */
link = getafield(act,A_VERBS);
/* look for this verb */
while (link != NIL) {
verb = verbs;
word = getword(link+L_DATA);
while (*verb != NIL && word != NIL) {
if (*verb != getword(word+L_DATA))
break;
verb++;
word = getword(word+L_NEXT);
}
if (*verb == NIL && word == NIL)
return (TRUE);
link = getword(link+L_NEXT);
}
return (FALSE);
}
/* exe_one - execute one instruction */
void exe_one(void)
{
/* get the opcode */
opcode = getcbyte(pc); pc++;
/* execute the instruction */
switch (opcode) {
case OP_CALL:
*--sp = getboperand();
*--sp = pc;
*--sp = (int)(top - fp);
fp = sp;
pc = getafield(fp[fp[2]+3],A_CODE);
break;
case OP_SEND:
*--sp = getboperand();
*--sp = pc;
*--sp = (int)(top - fp);
fp = sp;
if (p2 = fp[fp[2]+3])
p2 = getofield(p2,O_CLASS);
else
p2 = fp[fp[2]+2];
if (p2 && (p2 = getp(p2,fp[fp[2]+1]))) {
pc = getafield(p2,A_CODE);
break;
}
*sp = NIL;
/* return NIL if there is no method for this message */
case OP_RETURN:
if (fp == top)
sts = CHAIN;
else {
p2 = *sp;
sp = fp;
fp = top - *sp++;
pc = *sp++;
p3 = *sp++;
sp += p3;
*sp = p2;
}
break;
case OP_TSPACE:
sp -= getboperand();
break;
case OP_TMP:
p2 = getboperand();
*sp = fp[-p2-1];
break;
case OP_TSET:
p2 = getboperand();
fp[-p2-1] = *sp;
break;
case OP_ARG:
p2 = getboperand();
if (p2 >= fp[2])
error("too few arguments");
*sp = fp[p2+3];
break;
case OP_ASET:
p2 = getboperand();
if (p2 >= fp[2])
error("too few arguments");
fp[p2+3] = *sp;
break;
case OP_BRT:
pc = (*sp ? getwoperand() : pc+2);
break;
case OP_BRF:
pc = (*sp ? pc+2 : getwoperand());
break;
case OP_BR:
pc = getwoperand();
break;
case OP_T:
*sp = T;
break;
case OP_NIL:
*sp = NIL;
break;
case OP_PUSH:
*--sp = NIL;
break;
case OP_NOT:
*sp = (*sp ? NIL : T);
break;
case OP_ADD:
p2 = *sp++;
*sp += p2;
break;
case OP_SUB:
p2 = *sp++;
*sp -= p2;
break;
case OP_MUL:
p2 = *sp++;
*sp *= p2;
break;
case OP_DIV:
p2 = *sp++;
*sp = (p2 == 0 ? 0 : *sp / p2);
break;
case OP_REM:
p2 = *sp++;
*sp = (p2 == 0 ? 0 : *sp % p2);
break;
case OP_BAND:
p2 = *sp++;
*sp &= p2;
break;
case OP_BOR:
p2 = *sp++;
*sp |= p2;
break;
case OP_BNOT:
*sp = ~*sp;
break;
case OP_LT:
p2 = *sp++;
*sp = (*sp < p2 ? T : NIL);
break;
case OP_EQ:
p2 = *sp++;
*sp = (*sp == p2 ? T : NIL);
break;
case OP_GT:
p2 = *sp++;
*sp = (*sp > p2 ? T : NIL);
break;
case OP_LIT:
*sp = getwoperand();
break;
case OP_SPLIT:
*sp = getboperand();
break;
case OP_SNLIT:
*sp = -getboperand();
break;
case OP_VAR:
*sp = getvalue(getwoperand());
break;
case OP_SVAR:
*sp = getvalue(getboperand());
break;
case OP_SET:
setvalue(getwoperand(),*sp);
break;
case OP_SSET:
setvalue(getboperand(),*sp);
break;
case OP_GETP:
p2 = *sp++;
*sp = getp(*sp,p2);
break;
case OP_SETP:
p3 = *sp++;
p2 = *sp++;
*sp = setp(*sp,p2,p3);
break;
case OP_PRINT:
print(*sp);
break;
case OP_PNUMBER:
pnumber(*sp);
break;
case OP_PNOUN:
show_noun(*sp);
break;
case OP_TERPRI:
trm_chr('\n');
break;
case OP_FINISH:
sts = FINISH;
break;
case OP_CHAIN:
sts = CHAIN;
break;
case OP_ABORT:
sts = ABORT;
break;
case OP_EXIT:
#ifdef MAC
macpause();
#endif
trm_done();
exit();
break;
case OP_YORN:
trm_get(line);
*sp = (line[0] == 'Y' || line[0] == 'y' ? T : NIL);
break;
case OP_CLASS:
*sp = getofield(*sp,O_CLASS);
break;
case OP_MATCH:
p2 = *sp++;
*sp = (match(*sp,nouns[p2-1],adjectives[p2-1]) ? T : NIL);
break;
case OP_SAVE:
*sp = db_save();
break;
case OP_RESTORE:
*sp = db_restore();
break;
case OP_RESTART:
*sp = db_restart();
break;
case OP_RAND:
*sp = getrand(*sp);
break;
case OP_RNDMIZE:
setrand(time(0L));
*sp = NIL;
break;
default:
if (opcode >= OP_XVAR && opcode < OP_XSET)
*sp = getvalue(opcode - OP_XVAR);
else if (opcode >= OP_XSET && opcode < OP_XPLIT)
setvalue(opcode - OP_XSET,*sp);
else if (opcode >= OP_XPLIT && opcode < OP_XNLIT)
*sp = opcode - OP_XPLIT;
else if (opcode >= OP_XNLIT && opcode < 256)
*sp = OP_XNLIT - opcode;
else
trm_str("Bad opcode\n");
break;
}
}
/* haspreposition - check to see if an action has a specified preposition */
int haspreposition(int act, int preposition)
{
return (inlist(getafield(act,A_PREPOSITIONS),preposition));
}
