/* Execute a for loop. */
void exec_for(void)
{
int cond;
char *temp, *temp2;
int brace ;
get_token();
eval_exp(&cond); /* initialization expression */
if(*token != ';') sntx_err(SEMI_EXPECTED);
prog++; /* get past the ; */
temp = prog;
for(;;) {
eval_exp(&cond); /* check the condition */
if(*token != ';') sntx_err(SEMI_EXPECTED);
prog++; /* get past the ; */
temp2 = prog;
/* find the start of the for block */
brace = 1;
while(brace) {
get_token();
if(*token == '(') brace++;
if(*token == ')') brace--;
}
if(cond) interp_block(); /* if true, interpret */
else { /* otherwise, skip around loop */
find_eob();
return;
}
prog = temp2;
eval_exp(&cond); /* do the increment */
prog = temp; /* loop back to top */
}
}
void exec_for()
{
int cond;
char *temp, *temp2;
int brace ;
get_token();
eval_exp(&cond);
if(*token!=';')
sntx_err(SEMI_EXPECTED);
prog++;
temp = prog;
for(;;) {
eval_exp(&cond);
if(*token!=';')
sntx_err(SEMI_EXPECTED);
prog++;
temp2 = prog;
brace = 1;
while(brace) {
get_token();
if(*token=='(') brace++;
if(*token==')') brace--;
}
if(cond)
interp_block();
else {
find_eob();
return;
}
prog = temp2;
eval_exp(&cond);
prog = temp;
}
}
void exec_if()
{
int cond;
eval_exp(&cond);
if(cond) {
interp_block();
} else {
find_eob();
get_token();
if(tok!=ELSE) {
putback();
return;
}
interp_block();
}
}
/* Execute an if statement. */
void exec_if(void)
{
int cond;
eval_exp(&cond); /* get if expression */
if(cond) { /* is true so process target of IF */
interp_block();
}
else { /* otherwise skip around IF block and
process the ELSE, if present */
find_eob(); /* find start of next line */
get_token();
if(tok != ELSE) {
putback(); /* restore token if
no ELSE is present */
return;
}
interp_block();
}
}
void exec_do()
{
int cond;
char *temp;
putback();
temp = prog;
get_token();
interp_block();
get_token();
if(tok!=WHILE)
sntx_err(WHILE_EXPECTED);
eval_exp(&cond);
if(cond)
prog = temp;
}
/* Execute a do loop. */
void exec_do(void)
{
int cond;
char *temp;
putback();
temp = prog; /* save location of top of do loop */
get_token(); /* get start of loop */
interp_block(); /* interpret loop */
get_token();
if(tok != WHILE) sntx_err(WHILE_EXPECTED);
eval_exp(&cond); /* check the loop condition */
if(cond) prog = temp; /* if true loop; otherwise,
continue on */
}
/* Execute a while loop. */
void exec_while(void)
{
int cond;
char *temp;
putback();
temp = prog; /* save location of top of while loop */
get_token();
eval_exp(&cond); /* check the conditional expression */
if(cond) interp_block(); /* if true, interpret */
else { /* otherwise, skip around loop */
find_eob();
return;
}
prog = temp; /* loop back to top */
}
void exec_while()
{
int cond;
char *temp;
putback();
temp = prog;
get_token();
eval_exp(&cond);
if(cond)
interp_block();
else {
find_eob();
return;
}
prog = temp;
}
void call()
{
char *loc, *temp;
int lvartemp;
loc = find_func(token);
if(loc==NULL)
sntx_err(FUNC_UNDEF);
else {
lvartemp = lvartos;
get_args();
temp = prog;
func_push(lvartemp);
prog = loc;
get_params();
interp_block();
prog = temp;
lvartos = func_pop();
}
}
/* Call a function. */
void call(void)
{
char *loc, *temp;
int lvartemp;
loc = find_func(token); /* find entry point of function */
if(loc == NULL)
sntx_err(FUNC_UNDEF); /* function not defined */
else {
lvartemp = lvartos; /* save local var stack index */
get_args(); /* get function arguments */
temp = prog; /* save return location */
func_push(lvartemp); /* save local var stack index */
prog = loc; /* reset prog to start of function */
get_params(); /* load the function's parameters with
the values of the arguments */
interp_block(); /* interpret the function */
prog = temp; /* reset the program pointer */
lvartos = func_pop(); /* reset the local var stack */
}
}
