Method parseElem

runtime/sam/expr/function/unflatten.go:69–101

(inner super.Type, vb scode.Bytes)

}

func (u *Unflatten) parseElem(inner super.Type, vb scode.Bytes) (field.Path, super.Type, scode.Bytes, error) {
	if union, ok := super.TypeUnder(inner).(*super.TypeUnion); ok {
		inner, vb = union.Untag(vb)
	}
	typ := super.TypeRecordOf(inner)
	if typ == nil || len(typ.Fields) != 2 {
		return nil, nil, nil, nil
	}
	nkey, ok := typ.IndexOfField("key")
	if !ok {
		return nil, nil, nil, nil
	}

	vtyp, ok := typ.TypeOfField("value")
	if !ok {
		return nil, nil, nil, nil
	}
	it := scode.NewRecordIter(vb, 0)
	kbytes, _ := it.Next(false)
	vbytes, _ := it.Next(false)
	if nkey == 1 {
		kbytes, vbytes = vbytes, kbytes
	}
	ktyp := typ.Fields[nkey].Type
	if ktyp.ID() == super.IDString {
		u.path = append(u.path[:0], super.DecodeString(kbytes))
		return u.path, vtyp, vbytes, nil
	}
	if a, ok := super.TypeUnder(ktyp).(*super.TypeArray); ok && a.Type.ID() == super.IDString {
		return u.decodeKey(kbytes), vtyp, vbytes, nil
	}
	return nil, nil, nil, fmt.Errorf("invalid key type %s: expected either string or [string]", sup.FormatType(ktyp))
}

func (u *Unflatten) decodeKey(b scode.Bytes) field.Path {
	u.path = u.path[:0]