func iterStorage(ctx context.Context, store Store, txn Transaction, nonGround, ground ast.Ref, bindings *ast.ValueMap, iter func(*ast.ValueMap, interface{})) error {
if len(nonGround) == 0 {
path, err := NewPathForRef(ground)
if err != nil {
return err
}
node, err := store.Read(ctx, txn, path)
if err != nil {
if IsNotFound(err) {
return nil
}
return err
}
iter(bindings, node)
return nil
}
head := nonGround[0]
tail := nonGround[1:]
headVar, isVar := head.Value.(ast.Var)
if !isVar || len(ground) == 0 {
ground = append(ground, head)
return iterStorage(ctx, store, txn, tail, ground, bindings, iter)
}
path, err := NewPathForRef(ground)
if err != nil {
return err
}
node, err := store.Read(ctx, txn, path)
if err != nil {
if IsNotFound(err) {
return nil
}
return err
}
switch node := node.(type) {
case map[string]interface{}:
for key := range node {
ground = append(ground, ast.StringTerm(key))
cpy := bindings.Copy()
cpy.Put(headVar, ast.String(key))
err := iterStorage(ctx, store, txn, tail, ground, cpy, iter)
if err != nil {
return err
}
ground = ground[:len(ground)-1]
}
case []interface{}:
for i := range node {
idx := ast.IntNumberTerm(i)
ground = append(ground, idx)
cpy := bindings.Copy()
cpy.Put(headVar, idx.Value)
err := iterStorage(ctx, store, txn, tail, ground, cpy, iter)
if err != nil {
return err
}
ground = ground[:len(ground)-1]
}
}
return nil
}
