/* xlexpandmacros - expand macros in a form */
LVAL xlexpandmacros(LVAL form)
{
LVAL fun,args;
/* protect some pointers */
xlstkcheck(3);
xlprotect(form);
xlsave(fun);
xlsave(args);
/* expand until the form isn't a macro call */
while (consp(form)) {
fun = car(form); /* get the macro name */
args = cdr(form); /* get the arguments */
if (!symbolp(fun) || !fboundp(fun))
break;
fun = xlgetfunction(fun); /* get the expansion function */
if (!macroexpand(fun,args,&form))
break;
}
/* restore the stack and return the expansion */
xlpopn(3);
return (form);
}
/* x1macroexpand - expand a macro call */
LVAL x1macroexpand(void)
{
LVAL form,fun,args;
/* protect some pointers */
xlstkcheck(2);
xlsave(fun);
xlsave(args);
/* get the form */
form = xlgetarg();
xllastarg();
/* expand until the form isn't a macro call */
if (consp(form)) {
fun = car(form); /* get the macro name */
args = cdr(form); /* get the arguments */
if (symbolp(fun) && fboundp(fun)) {
fun = xlgetfunction(fun); /* get the expansion function */
macroexpand(fun,args,&form);
}
}
/* restore the stack and return the expansion */
xlpopn(2);
return (form);
}
/* xfunction - special form 'function' */
LVAL xfunction(V)
{
LVAL val;
/* get the argument */
val = xlgetarg();
xllastarg();
/* create a closure for lambda expressions */
if (consp(val) && car(val) == s_lambda && consp(cdr(val)))
val = xlclose(NIL,s_lambda,car(cdr(val)),cdr(cdr(val)),xlenv,xlfenv);
/* otherwise, get the value of a symbol */
else if (symbolp(val))
val = xlgetfunction(val);
/* otherwise, its an error */
else
xlerror("not a function",val);
/* return the function */
return (val);
}
/* evform - evaluate a form */
LOCAL LVAL evform(LVAL form)
{
LVAL fun,args,val,type;
LVAL tracing=NIL;
LVAL *argv;
LVAL old_profile_fixnum = profile_fixnum;
FIXTYPE *old_profile_count_ptr = profile_count_ptr;
LVAL funname;
int argc;
/* protect some pointers */
xlstkcheck(2);
xlsave(fun);
xlsave(args);
(*profile_count_ptr)++; /* increment profile counter */
/* get the function and the argument list */
fun = car(form);
args = cdr(form);
funname = fun;
/* get the functional value of symbols */
if (symbolp(fun)) {
if (getvalue(s_tracelist) && member(fun,getvalue(s_tracelist)))
tracing = fun;
fun = xlgetfunction(fun);
}
/* check for nil */
if (null(fun))
xlerror("bad function",NIL);
/* dispatch on node type */
switch (ntype(fun)) {
case SUBR:
argv = xlargv;
argc = xlargc;
xlargc = evpushargs(fun,args);
xlargv = xlfp + 3;
trenter(tracing,xlargc,xlargv);
val = (*getsubr(fun))();
trexit(tracing,val);
xlsp = xlfp;
xlfp = xlfp - (int)getfixnum(*xlfp);
xlargv = argv;
xlargc = argc;
break;
case FSUBR:
argv = xlargv;
argc = xlargc;
xlargc = pushargs(fun,args);
xlargv = xlfp + 3;
val = (*getsubr(fun))();
xlsp = xlfp;
xlfp = xlfp - (int)getfixnum(*xlfp);
xlargv = argv;
xlargc = argc;
break;
case CONS:
if (!consp(cdr(fun)))
xlerror("bad function",fun);
if ((type = car(fun)) == s_lambda)
fun = xlclose(NIL,
s_lambda,
car(cdr(fun)),
cdr(cdr(fun)),
xlenv,xlfenv);
else
xlerror("bad function",fun);
/**** fall through into the next case ****/
case CLOSURE:
/* do profiling */
if (profile_flag && atomp(funname)) {
LVAL profile_prop = findprop(funname, s_profile);
if (null(profile_prop)) {
/* make a new fixnum, don't use cvfixnum because
it would return shared pointer to zero, but we
are going to modify this integer in place --
dangerous but efficient.
*/
profile_fixnum = newnode(FIXNUM);
profile_fixnum->n_fixnum = 0;
setplist(funname, cons(s_profile,
cons(profile_fixnum,
getplist(funname))));
setvalue(s_profile, cons(funname, getvalue(s_profile)));
} else profile_fixnum = car(profile_prop);
profile_count_ptr = &getfixnum(profile_fixnum);
}
if (gettype(fun) == s_lambda) {
argc = evpushargs(fun,args);
argv = xlfp + 3;
trenter(tracing,argc,argv);
val = evfun(fun,argc,argv);
trexit(tracing,val);
xlsp = xlfp;
xlfp = xlfp - (int)getfixnum(*xlfp);
}
else {
macroexpand(fun,args,&fun);
val = xleval(fun);
}
profile_fixnum = old_profile_fixnum;
profile_count_ptr = old_profile_count_ptr;
break;
default:
xlerror("bad function",fun);
}
/* restore the stack */
xlpopn(2);
/* return the result value */
return (val);
}
