/*
* Shift in the next symbol from the input stream
*
* Return SUCCESS or FAIL
*/
FUNCTION CODE shift
(
struct SYNBLK *sb,
struct PSTATE *statelist[], /* in: array of pointers to states */
struct VALUE *value, /* out: value of the primitive */
CODE *symbtype, /* out: type of the primitive */
CODE *lookahead /* out: the peeked-at next symbol */
)
{
CODE code;
*symbtype= getprim(sb, value); /* get a primary symbol and value */
if (*symbtype == PA_ERROR) /* assume GETPRIM prints error */
return(FAIL);
if (*symbtype == PA_ERRFLOW) /* underflow or overflow */
return(PA_ERRFLOW);
*lookahead = peekpri(sb); /* look at the next symbol in line */
if (*lookahead == PA_ERROR)
code = FAIL;
else if (*lookahead == PA_ERRFLOW)
code = PA_ERRFLOW;
else
code = gotostate(statelist, *symbtype); /* fix state stack for next state */
if (code == FAIL || code == PA_ERRFLOW)
deal_pval(value, *symbtype); /* deallocate any string */
return(code);
}
/*
* Parse the line starting at the current syntax block pointer until
* end-of-string, using state tables provided by the caller. Trigger any
* 'action' routines as indicated by the provided state table.
*
* Returns PA_SUCC or PA_FAIL or PA_EOS (failure on unexpected EOS)
*/
FUNCTION CODE parser
(
struct SYNBLK *sb, /* in: syntax block */
struct PSTATE *statelist[], /* in: list of state pointers */
FUNINT state0, /* in: index of pointer to start state */
/* (W.R.T. the statelist) */
struct ERRMSG *(*errmsg) /* out: ptr to error msg struct */
)
{
CODE code, status;
CODE newsymb; /* new language symbol reduced to */
CODE symbtype;
CODE lookahead; /* next primitive symbol from input */
struct VALUE value; /* value of primitive from input */
*errmsg = NULL; /* init ptr to error msg */
inivstack(MAX_VAL_NEST); /* initialize value stack */
stk_in(st_stack, MAXSTATE, state0); /* init stack, push state0 */
do {
code = shift(sb, statelist, &value, &symbtype, &lookahead); /* do a shift operation */
if (code==FAIL)
{
if (symbtype==EOS)
return(PA_EOS);
return(PA_FAIL);
}
else
if (code==PA_ERRFLOW)
return(PA_ERRFLOW);
if (symbtype==PA_NUM || symbtype==PA_NAME
|| symbtype==PA_QUOTED || symbtype==PA_NULL)
{
code = pushvstack(&value); /* if not an operator push the value */
if (code == FAIL)
return(PA_FAIL); /* assume user over-nested */
}
while ( reduce(statelist, lookahead, &value, &newsymb, &status, errmsg)) /* reduce as much as possible */
{
if (status == FAIL) return(PA_FAIL); /* error message set up by action */
if (newsymb == PA_ACCEPT || newsymb == PA_ERROR) break; /* we're done */
code = gotostate(statelist, newsymb); /* fix state stack according to */
/* new symbol */
if (code == FAIL)
{
tmierr(TMI_XSTATE); /* fatal error: new state undeterminable */
return(PA_FAIL);
}
}
}
while( newsymb != PA_ACCEPT && newsymb != PA_ERROR); /* continue until we hit the 'accept' sym */
return(PA_SUCC);
}
void reduce(int reduction)
/* Completes a reduction */
{
struct TOKENREC token1, token2;
int counter;
switch (reduction)
{
case 1 :
token1 = pop();
pop();
token2 = pop();
curtoken.x.value = token1.x.value + token2.x.value;
break;
case 2 :
token1 = pop();
pop();
token2 = pop();
curtoken.x.value = token2.x.value - token1.x.value;
break;
case 4 :
token1 = pop();
pop();
token2 = pop();
curtoken.x.value = token1.x.value * token2.x.value;
break;
case 5 :
token1 = pop();
pop();
token2 = pop();
if (token1.x.value == 0)
curtoken.x.value = HUGE_VAL;
else
curtoken.x.value = token2.x.value / token1.x.value;
break;
case 7 :
token1 = pop();
pop();
token2 = pop();
curtoken.x.value = pow(token2.x.value, token1.x.value);
break;
case 9 :
token1 = pop();
pop();
curtoken.x.value = -token1.x.value;
break;
case 11 :
token1 = pop();
pop();
token2 = pop();
curtoken.x.value = 0;
if (token1.x.c.row == token2.x.c.row)
{
if (token1.x.c.col < token2.x.c.col)
error = TRUE;
else
{
for (counter = token2.x.c.col; counter <= token1.x.c.col; counter++)
curtoken.x.value += cellvalue(counter, token1.x.c.row);
}
}
else if (token1.x.c.col == token2.x.c.col)
{
if (token1.x.c.row < token2.x.c.row)
error = TRUE;
else
{
for (counter = token2.x.c.row; counter <= token1.x.c.row; counter++)
curtoken.x.value += cellvalue(token1.x.c.col, counter);
}
}
else
error = TRUE;
break;
case 13 :
curtoken = pop();
curtoken.x.value = cellvalue(curtoken.x.c.col, curtoken.x.c.row);
break;
case 14 :
pop();
curtoken = pop();
pop();
break;
case 16 :
pop();
curtoken = pop();
pop();
token1 = pop();
if (strcmp(token1.x.funcname, "ABS") == 0)
curtoken.x.value = fabs(curtoken.x.value);
else if (strcmp(token1.x.funcname, "ACOS") == 0)
curtoken.x.value = acos(curtoken.x.value);
else if (strcmp(token1.x.funcname, "ASIN") == 0)
curtoken.x.value = asin(curtoken.x.value);
else if (strcmp(token1.x.funcname, "ATAN") == 0)
curtoken.x.value = atan(curtoken.x.value);
else if (strcmp(token1.x.funcname, "COSH") == 0)
curtoken.x.value = cosh(curtoken.x.value);
else if (strcmp(token1.x.funcname, "COS") == 0)
curtoken.x.value = cos(curtoken.x.value);
else if (strcmp(token1.x.funcname, "EXP") == 0)
curtoken.x.value = exp(curtoken.x.value);
else if (strcmp(token1.x.funcname, "LOG10") == 0)
curtoken.x.value = log10(curtoken.x.value);
else if (strcmp(token1.x.funcname, "LOG") == 0)
curtoken.x.value = log(curtoken.x.value);
else if (strcmp(token1.x.funcname, "ROUND") == 0)
curtoken.x.value = (int)(curtoken.x.value + 0.5);
else if (strcmp(token1.x.funcname, "POW10") == 0)
curtoken.x.value = pow10(curtoken.x.value);
else if (strcmp(token1.x.funcname, "SINH") == 0)
curtoken.x.value = sinh(curtoken.x.value);
else if (strcmp(token1.x.funcname, "SIN") == 0)
curtoken.x.value = sin(curtoken.x.value);
else if (strcmp(token1.x.funcname, "SQRT") == 0)
curtoken.x.value = sqrt(curtoken.x.value);
else if (strcmp(token1.x.funcname, "SQR") == 0)
curtoken.x.value *= curtoken.x.value;
else if (strcmp(token1.x.funcname, "TANH") == 0)
curtoken.x.value = tanh(curtoken.x.value);
else if (strcmp(token1.x.funcname, "TAN") == 0)
curtoken.x.value = tan(curtoken.x.value);
else if (strcmp(token1.x.funcname, "TRUNC") == 0)
curtoken.x.value = (int)curtoken.x.value;
break;
case 3 :
case 6 :
case 8 :
case 10 :
case 12 :
case 15 :
curtoken = pop();
break;
} /* switch */
curtoken.state = gotostate(reduction);
push(&curtoken);
} /* reduce */
