void print_sexpr(cell_t * list, int depth, file_io_t * out, file_io_t * err)
{
char buf[MAX_STR];
cell_t *tmp;
if (list == NULL) {
print_error("print_sexpr was passed a NULL!", err);
return;
}
if (list->type == type_null) {
print_space(depth + 1, out);
print_string("Null\n", out);
return;
} else if (list->type == type_number) {
print_space(depth + 1, out);
sprintf(buf, "%d", list->car.i);
print_string(buf, out);
wrap_put(out, '\n');
} else if (list->type == type_str) {
print_space(depth + 1, out);
wrap_put(out, '"');
print_string(list->car.s, out);
wrap_put(out, '"');
wrap_put(out, '\n');
return;
} else if (list->type == type_symbol) {
print_space(depth + 1, out);
print_string(list->car.s, out);
wrap_put(out, '\n');
return;
} else if (list->type == type_list) {
if (depth == 0) {
print_string("(\n", out);
}
for (tmp = list; tmp != NULL; tmp = tmp->cdr.cell) {
if (tmp->car.cell != NULL && tmp->type == type_list) {
print_space(depth + 1, out);
print_string("(\n", out);
print_sexpr(tmp->car.cell, depth + 1, out, err);
print_space(depth + 1, out);
print_string(")\n", out);
}
if (tmp->type != type_list) {
print_sexpr(tmp, depth + 1, out, err);
}
}
if (depth == 0) {
print_string(")\n", out);
}
}
return;
}
sexpr_t* eval(sexpr_t* sexpr, sexpr_t** env, sexpr_list_t* roots, error_t** error)
{
if(sexpr == NULL) {
return interp.nil_sym;
}
/* printf("[eval]\n"); */
/* print_sexpr(sexpr); */
/* printf("\n"); */
roots = cons_to_roots_list(roots, sexpr);
gc_collect(roots);
if(ATOM(sexpr)) {
if(SYM(sexpr)) {
if(interp.t_sym == sexpr) {
return interp.t_sym;
}
if(interp.nil_sym == sexpr) {
return interp.nil_sym;
}
sexpr_t* val = assoc(sexpr, *env);
if(val == NULL) {
*error = mk_error("Undefined symbol", SYM_VAL(sexpr));
}
return val;
}
if(INT(sexpr)) {
return sexpr;
}
} else if(ATOM(CAR(sexpr))) {
if(SYM(CAR(sexpr))) {
// quote
if(interp.quote_sym == CAR(sexpr)) {
if(CDR(sexpr) == NULL) {
*error = mk_error("Missing quote argument", "");
return NULL;
}
if(CDR(CDR(sexpr)) != NULL) {
*error = mk_error("Too many arguments for quote", "");
return NULL;
}
return CAR(CDR(sexpr));
}
// atom
if(interp.atom_sym == CAR(sexpr)) {
if(ATOM(eval(CAR(CDR(sexpr)), env, roots, error))) {
return interp.t_sym;
}
return interp.nil_sym;
}
// eq
if(interp.eq_sym == CAR(sexpr)) {
// TODO check nb args
sexpr_t* e1 = eval(CAR(CDR(sexpr)), env, roots, error);
if(*error != NULL) {
return NULL;
}
roots = cons_to_roots_list(roots, e1);
sexpr_t* e2 = eval(CAR(CDR(CDR(sexpr))), env, roots, error);
if(*error != NULL) {
return NULL;
}
if(INT(e1) && INT(e2)) {
if(INT_VAL(e1) == INT_VAL(e2)) {
return interp.t_sym;
}
return interp.nil_sym;
}
if(e1 == e2) {
return interp.t_sym;
}
return interp.nil_sym;
}
// if
if(interp.if_sym == CAR(sexpr)) {
sexpr_t* e1 = eval(CAR(CDR(sexpr)), env, roots, error);
if(*error != NULL) {
return NULL;
}
if(e1 == interp.nil_sym) {
return eval(CAR(CDR(CDR(CDR(sexpr)))), env, roots, error);
} else {
return eval(CAR(CDR(CDR(sexpr))), env, roots, error);
}
}
// car
if(interp.car_sym == CAR(sexpr)) {
sexpr_t* e1 = eval(CAR(CDR(sexpr)), env, roots, error);
if(*error != NULL) {
return NULL;
}
if(e1 == interp.nil_sym) {
return interp.nil_sym;
}
return CAR(e1);
}
// cdr
if(interp.cdr_sym == CAR(sexpr)) {
sexpr_t* e1 = eval(CAR(CDR(sexpr)), env, roots, error);
if(*error != NULL) {
return NULL;
}
if(e1 == interp.nil_sym) {
return interp.nil_sym;
}
sexpr_t *res = CDR(e1);
if(res == NULL) {
return interp.nil_sym;
}
return res;
}
// +
if(interp.plus_sym == CAR(sexpr)) {
sexpr_t* e1 = eval(CAR(CDR(sexpr)), env, roots, error);
if(*error != NULL) {
return NULL;
}
roots = cons_to_roots_list(roots, e1);
sexpr_t* e2 = eval(CAR(CDR(CDR(sexpr))), env, roots, error);
if(*error != NULL) {
return NULL;
}
if(INT(e1) && INT(e2)) {
return mk_int(INT_VAL(e1) + INT_VAL(e2));
}
*error = mk_error("Arguments for '+' are not integers", "");
return NULL;
}
// -
if(interp.minus_sym == CAR(sexpr)) {
sexpr_t* e1 = eval(CAR(CDR(sexpr)), env, roots, error);
if(*error != NULL) {
return NULL;
}
roots = cons_to_roots_list(roots, e1);
sexpr_t* e2 = eval(CAR(CDR(CDR(sexpr))), env, roots, error);
if(*error != NULL) {
return NULL;
}
if(INT(e1) && INT(e2)) {
return mk_int(INT_VAL(e1) - INT_VAL(e2));
}
*error = mk_error("Arguments for '-' are not integers", "");
return NULL;
}
if(interp.mul_sym == CAR(sexpr)) {
sexpr_t* e1 = eval(CAR(CDR(sexpr)), env, roots, error);
if(*error != NULL) {
return NULL;
}
roots = cons_to_roots_list(roots, sexpr);
sexpr_t* e2 = eval(CAR(CDR(CDR(sexpr))), env, roots, error);
if(*error != NULL) {
return NULL;
}
if(INT(e1) && INT(e2)) {
return mk_int(INT_VAL(e1) * INT_VAL(e2));
}
*error = mk_error("Arguments for '*' are not integers", "");
return NULL;
}
// cons
if(interp.cons_sym == CAR(sexpr)) {
sexpr_t* e1 = eval(CAR(CDR(sexpr)), env, roots, error);
if(*error != NULL) {
return NULL;
}
roots = cons_to_roots_list(roots, e1);
sexpr_t* e2 = eval(CAR(CDR(CDR(sexpr))), env, roots, error);
if(*error != NULL) {
return NULL;
}
return mk_cons(e1 == interp.nil_sym ? NULL : e1, e2 == interp.nil_sym ? NULL : e2);
}
// def
if(interp.def_sym == CAR(sexpr)) {
sexpr_t* arg = CAR(CDR(CDR(sexpr)));
roots = cons_to_roots_list(roots, arg);
sexpr_t* val = eval(arg, env, roots, error);
if(*error != NULL) {
return NULL;
}
*env = mk_cons(mk_cons(intern(SYM_VAL(CAR(CDR(sexpr)))), val), *env);
return val;
}
// print
if(interp.print_sym == CAR(sexpr)) {
sexpr_t* e1 = eval(CAR(CDR(sexpr)), env, roots, error);
if(*error != NULL) {
return NULL;
}
print_sexpr(e1);
printf("\n");
return e1;
}
// fn
if(interp.fn_sym == CAR(sexpr)) {
return mk_fn(sexpr, *env);
}
// macro
if(interp.macro_sym == CAR(sexpr)) {
return mk_macro(sexpr);
}
//eval
if(interp.eval_sym == CAR(sexpr)) {
sexpr_t* e1 = eval(CAR(CDR(sexpr)), env, roots, error);
if(*error != NULL) {
return NULL;
}
roots = cons_to_roots_list(roots, e1);
return eval(e1, env, roots, error);
}
// else resolves first variable
sexpr_t* fn = eval(CAR(sexpr), env, roots, error);
if(*error != NULL) {
return NULL;
}
// eval fn
if(FN(fn)) {
sexpr_t* fn_code = CAR(CDR(CDR(CAR(fn))));
sexpr_t* captured_env = CDR(fn);
sexpr_t* arguments = eval_list(CDR(sexpr), env, roots, error);
if(*error != NULL) {
return NULL;
}
sexpr_t* pairs = pair(CAR(CDR(CAR(fn))), arguments);
sexpr_t* eval_env = append(pairs, captured_env);
// append the function itself to the env, roots, for recursive calls
eval_env = mk_cons(mk_cons(CAR(sexpr), fn), eval_env);
/* printf("fn code=\n"); */
/* print_sexpr(fn_code); */
/* printf("\n"); */
roots = cons_to_roots_list(roots, eval_env);
return eval(fn_code, &eval_env, roots, error);
}
// eval macro
if(MACRO(fn)) {
sexpr_t* macro_code = CAR(CDR(CDR(CAR(fn))));
sexpr_t* pairs = pair(CAR(CDR(CAR(fn))), CDR(sexpr));
sexpr_t* eval_env = append(pairs, *env);
roots = cons_to_roots_list(roots, eval_env);
sexpr_t* transformed_code = eval(macro_code, &eval_env, roots, error);
if(*error != NULL) {
return NULL;
}
return eval(transformed_code, env, roots, error);
}
// else primitives
sexpr_t* arguments = eval_list(CDR(sexpr), env, roots, error);
if(*error != NULL) {
return NULL;
}
sexpr_t* to_eval = mk_cons(fn, arguments);
return eval(to_eval, env, roots, error);
}
} else if(CAR(CAR(sexpr)) == interp.fn_sym) {
// executes an anonymous function
sexpr_t* fn = CAR(sexpr);
sexpr_t* fn_code = CAR(CDR(CDR(fn)));
sexpr_t* arguments = eval_list(CDR(sexpr), env, roots, error);
if(*error != NULL) {
return NULL;
}
sexpr_t* l = pair(CAR(CDR(fn)), arguments);
l = append(l, *env);
roots = cons_to_roots_list(roots, l);
return eval(fn_code, &l, roots, error);
}
print_sexpr(sexpr);
printf("\n");
*error = mk_error("Invalid expression", "");
return NULL;
}