Haskell语法 - 如何写入让括号中的块？

Question

以下代码在let子句中得到了"解析错误"(在GHC 7.8.3中):

someFunction = do {
    let foo = bar;
    return foo;
}

如何纠正它以获得相当于此？

someFunction = do
    let foo = bar
    return foo

Answer 1

someFunction = do {
    let foo = bar
  ; return foo
}

要么

someFunction = do {
    let { foo = bar };
    return foo
}