无法获取记录的记录属性

我有这个

{ a |
    b = { a.b |
        c =
            Utils.newC
                a.b.c
        }
}

但是编译器只是说“ no”：

-- SYNTAX PROBLEM ----------------------------------------------------- Main.elm
I ran into something unexpected when parsing your code!

43|                  b = { a.b |
                            ^
I am looking for one of the following things:

     "'"
     "|"
     an equals sign '='
     more letters in this name
     whitespace

我现在不知道该怎么办。如何获得a与c财产b更改为新的价值？