LValue *l_eval_var_node(LNode *node, LClosure *closure) {
LValue *value = l_closure_get(closure, node->val);
if(value != NULL) {
return value;
} else {
value = l_value_new(L_ERR_TYPE, closure);
value->core.str = make_stringbuf(node->val);
buffer_concat(value->core.str, " not found");
l_handle_error(value, node, closure);
return value;
}
}
LValue *l_eval_call_node(LNode *node, LValue *func, LClosure *closure) {
if(func == NULL) func = l_eval_var_node(node, closure);
char *name = (node != NULL) ? node->val : "";
LValue *value, *args_val;
LNode *expr;
int i;
// create a running scope to hold arguments
// and a reference to self (for recursion)
// TODO this may not be necessary (can't we just do `cl=func->core.func.closure`?)
LClosure *cl = l_closure_clone(func->core.func.closure, node);
tail_loop:
l_debug(L_DEBUG_CALL) {
if(node) printf(">>> entering %s on line %d in %s\n", name, node->line_no, node->source_file);
else printf(">>> entering %s\n", name);
}
if(strcmp(name, "") != 0)
l_closure_set(cl, name, func, true);
args_val = l_eval_call_args(node, func, closure, cl);
if(func->core.func.ptr != NULL) {
// native C code
if(!setjmp(cl->jmp)) {
value = func->core.func.ptr(args_val, cl);
} else {
// function called longjmp to initiate a tail call
l_debug(L_DEBUG_CALL) printf("^^^ reached end of %s (longjmp tail call)\n", name);
node = NULL;
func = l_closure_get(cl, "--tail-call--");
closure = cl;
l_closure_backfill(func->core.func.closure, cl, node);
name = "";
goto tail_loop;
}
} else {
// Lydia code
int exprc = func->core.func.exprc;
if(exprc > 0) {
// eval all but the last expression
for(i=0; i<exprc-1; i++) {
expr = func->core.func.exprs[i];
value = l_eval_node(expr, cl);
}
expr = func->core.func.exprs[exprc-1];
if(expr->type == L_CALL_TYPE) { // tail call
l_debug(L_DEBUG_CALL) printf("^^^ reached end of %s (tail call)\n", name);
node = expr;
func = l_eval_var_node(node, cl);
closure = cl;
l_closure_backfill(func->core.func.closure, cl, node);
name = node->val;
goto tail_loop;
} else {
value = l_eval_node(expr, cl);
}
} else {
value = l_value_new(L_NIL_TYPE, cl);
}
}
l_closure_free(cl);
l_debug(L_DEBUG_CALL) printf("<<< returning from %s\n", name);
return value;
}
