lval* lval_call(lenv* e, lval* f, lval* a) {
/* If Builtin then simply apply that */
if (f->builtin) { return f->builtin(e, a); }
/* Record Argument Counts */
int given = a->count;
int total = f->formals->count;
/* While arguments still remain to be processed */
while (a->count) {
/* If we've ran out of formal arguments to bind */
if (f->formals->count == 0) {
lval_del(a);
return lval_err("Function passed too many arguments. Got %i, Expected %i.", given, total);
}
/* Pop the first symbol from the formals */
lval* sym = lval_pop(f->formals, 0);
/* Special Case to deal with '&' */
if (strcmp(sym->sym, "&") == 0) {
/* Ensure '&' is followed by another symbol */
if (f->formals->count != 1) {
lval_del(a);
return lval_err("Function format invalid. Symbol '&' not followed by single symbol.");
}
/* Next formal should be bound to remaining arguments */
lval* nsym = lval_pop(f->formals, 0);
lenv_put(f->env, nsym, builtin_list(e, a));
lval_del(sym); lval_del(nsym);
break;
}
/* Pop the next argument from the list */
lval* val = lval_pop(a, 0);
/* Bind a copy into the function's environment */
lenv_put(f->env, sym, val);
/* Delete symbol and value */
lval_del(sym); lval_del(val);
}
/* Argument list is now bound so can be cleaned up */
lval_del(a);
/* If '&' remains in formal list it should be bound to empty list */
if (f->formals->count > 0 &&
strcmp(f->formals->cell[0]->sym, "&") == 0) {
/* Check to ensure that & is not passed invalidly. */
if (f->formals->count != 2) {
return lval_err("Function format invalid. Symbol '&' not followed by single symbol.");
}
/* Pop and delete '&' symbol */
lval_del(lval_pop(f->formals, 0));
/* Pop next symbol and create empty list */
lval* sym = lval_pop(f->formals, 0);
lval* val = lval_qexpr();
/* Bind to environment and delete */
lenv_put(f->env, sym, val);
lval_del(sym); lval_del(val);
}
/* If all formals have been bound evaluate */
if (f->formals->count == 0) {
/* Set Function Environment parent to current evaluation Environment */
f->env->par = e;
/* Evaluate and return */
return builtin_eval(f->env, lval_add(lval_sexpr(), lval_copy(f->body)));
} else {
/* Otherwise return partially evaluated function */
return lval_copy(f);
}
}
lval* lval_call(lenv* e, lval* f, lval* a) {
if (f->builtin) {
return f->builtin(e, a);
}
int given = a->count;
int total = f->formals->count;
while (a->count) {
if (f->formals->count == 0) {
lval_del(a);
return lval_err("Function passed too many arguments. Expected %i, Got %i.", total, given);
}
lval* sym = lval_pop(f->formals, 0);
// Variadic operator
if (strcmp(sym->sym, "&") == 0){
if (f->formals->count != 1) {
lval_del(a);
return lval_err("Function format invalid. "
"Symbol '&' not followed by a single symbol");
}
lval* nsym = lval_pop(f->formals, 0);
lenv_put(f->env, nsym, builtin_list(e, a));
lval_del(sym);
lval_del(nsym);
break;
}
lval* val = lval_pop(a, 0);
lenv_put(f->env, sym, val);
lval_del(val);
lval_del(sym);
}
lval_del(a);
// If '&' remains in formal list bind to empty list
if (f->formals->count > 0 &&
strcmp(f->formals->cell[0]->sym, "&") == 0) {
if (f->formals->count != 2) {
return lval_err("Function format invalid. "
"Symbol '&' not followed by a single symbol");
}
lval_del(lval_pop(f->formals, 0));
lval* sym = lval_pop(f->formals, 0);
lval* val = lval_qexpr();
lenv_put(f->env, sym, val);
lval_del(val);
lval_del(sym);
}
if (f->formals->count == 0) {
f->env->par = e;
return builtin_eval(f->env, lval_add(lval_sexpr(), lval_copy(f->body)));
} else {
return lval_copy(f);
}
}
Value* tl_val_call(Env* e, Value* fn, Value* args) {
if(fn->builtin) { return fn->builtin(e, args); }
int given = args->count;
int total = fn->formals->count;
while (args->count) {
if (fn->formals->count == 0) {
tl_val_delete(args);
return tl_val_error(
"Function passed too many arguments. "
"Got %i, expected %i.", given, total);
}
Value* sym = tl_val_pop(fn->formals, 0);
if (strcmp(sym->sym, "&") == 0) {
if (fn->formals->count != 1) {
tl_val_delete(args);
return tl_val_error("Function format invalid."
"Symbol '&' not followed by single symbol");
}
Value* symbols = tl_val_pop(fn->formals, 0);
tl_env_put(fn->env, symbols, builtin_list(e, args));
tl_val_delete(sym);
tl_val_delete(symbols);
break;
}
Value* val = tl_val_pop(args, 0);
tl_env_put(fn->env, sym, val);
tl_val_delete(sym);
tl_val_delete(val);
}
if (fn->formals->count > 0 && strcmp(fn->formals->cell[0]->sym, "&") == 0) {
if (fn->formals->count != 2) {
return tl_val_error("Function format invalid."
"Symbol '&' not followed by single symbol");
}
tl_val_delete(tl_val_pop(fn->formals, 0));
Value* symbol = tl_val_pop(fn->formals, 0);
Value* value = tl_val_qexpr();
tl_env_put(e, symbol, value);
tl_val_delete(symbol);
tl_val_delete(value);
}
tl_val_delete(args);
if (fn->formals->count == 0) {
// Eval and return if all formals have been bound
fn->env->parent = e;
return builtin_eval(fn->env,
tl_val_add(tl_val_sexpr(), tl_val_copy(fn->body)));
} else {
// Partially evaluated function
return tl_val_copy(fn);
}
}
