重塑平坦的父/子结构以在芝麻中创建分层结构

Question

在创建一个代表其实际级别的结构时，我面临一个挑战。当我使用递归功能时，我会将所有子级都置于一个级别之下。

{
"id": "foo-structure",
"type": "pipe",
"source": {
  "type": "dataset",
  "dataset": "parent-children-relations"
},
"transform": {
  "type": "dtl",
  "rules": {
    "default": [
      [
        "copy",
        "*"
      ],
      [
        "add",
        "children",
        [
          "apply-hops",
          "foo",
          {
            "datasets": [
              "parent-children-relations pcr"
            ],
            "where": [
              [
                "eq",
                "_S.foo",
                "pcr.bar"
              ]
            ],
            "recurse": true,
            "max_depth": 10,
            "exclude_root": true
          }
        ]
      ]
    ],
    "foo": [
      [
        "copy",
        "*"
      ]
    ]
  }
}

} 像这样：

"top-level": [ {"child1"}, {"child2"}, {"child1.2"}]

孩子1.2是孩子1的孩子。

所需结果如下：

"top-level": [{"child1":[ {"child1.2"}]}, {"child2"}]

我尝试了不使用递归的方法，只是使用新规则跳回到了相同的数据集，并且它可以工作，但是感觉好像有更好的解决方案。现在看起来像这样：

{
  "_id": "foo-structure",
  "type": "pipe",
  "source": {
    "type": "dataset",
    "dataset": "parent-children-relations"
  },
   "transform": {
    "type": "dtl",
    "rules": {
      "default": [
      ["copy", "*"],
        ["add", "children-members",
          ["apply-hops", "bar", {
        "datasets": ["global-children-members gcm"],
        "where": [
          ["eq", "_S.id", "gcm.id"]
        ]
      }]
    ],
    ["add", "children",
      ["apply-hops", "foo", {
        "datasets": ["parent-children-relations pcr"],
        "where": [
          ["eq", "_S.foo", "pcr.bar"]
        ]
      }]
    ]
  ],
  "bar": [
    ["copy", "*"]
  ],
  "child": [
    ["if",
      ["-is-not-null", "_S.foo"],
      ["add", "children",
        ["apply-hops", "child1", {
          "datasets": ["parent-children-relations pcr"],
          "where": [
            ["eq", "_S.foo", "pcr.bar""]
          ]
        }]
      ]
    ],
    ["add", "children-member"
      ["apply-hops", "bar", {
        "datasets": ["global-children-members gcm"],
        "where": [
          ["eq", "_S.id", "gcm.id"]
        ]
      }]
    ]
  ],
  "child1": [
    ["if",
      ["-is-not-null", "_S.foo"],
      ["add", "children",
        ["apply-hops", "child2", {
          "datasets": ["parent-children-relations pcr"],
          "where": [
            ["eq", "_S.foo", "pcr.bar""]
          ]
        }]
      ]
    ],
    ["add", "children-member"
      ["apply-hops", "bar", {
        "datasets": ["global-children-members gcm"],
        "where": [
          ["eq", "_S.id", "gcm.id"]
        ]
      }]
    ]
  ],
  "child2": [
    ["if",
      ["-is-not-null", "_S.foo"],
      ["add", "children",
        ["apply-hops", "child3", {
          "datasets": ["parent-children-relations pcr"],
          "where": [
            ["eq", "_S.foo", "pcr.bar""]
          ]
        }]
      ]
    ],
    ["add", "children-member"
      ["apply-hops", "bar", {
        "datasets": ["global-children-members gcm"],
        "where": [
          ["eq", "_S.id", "gcm.id"]
        ]
      }]
    ]
  ],
  "child3": [
    ["if",
      ["-is-not-null", "_S.foo"],
      ["add", "children",
        ["apply-hops", "child4", {
          "datasets": ["parent-children-relations pcr"],
          "where": [
            ["eq", "_S.foo", "pcr.bar""]
          ]
        }]
      ]
    ],
    ["add", "children-member"
      ["apply-hops", "bar", {
        "datasets": ["global-children-members gcm"],
        "where": [
          ["eq", "_S.id", "gcm.id"]
        ]
      }]
    ]
  ],
  "child4": [
    ["copy", "*"],
    ["if",
      ["-is-not-null", "_S.foo"],
      ["add", "children",
        ["apply-hops", "child5", {
          "datasets": ["parent-children-relations pcr"],
          "where": [
            ["eq", "_S.foo", "pcr.bar""]
          ]
        }]
      ]
    ],
    ["add", "children-member"
      ["apply-hops", "bar", {
        "datasets": ["global-children-members"],
        "where": [
          ["eq", "_S.id", "gcm.id"]
        ]
      }]
    ]
  ],
   "child5": [
    ["if",
      ["-is-not-null", "_S.foo"],
      ["comment", "children",
        ["apply-hops", "child5", {
          "datasets": ["parent-children-relations pcr"],
          "where": [
            ["eq", "_S.foo", "pcr.bar""]
          ]
        }]
      ]
    ],
    ["add", "children-member"
      ["apply-hops", "bar", {
        "datasets": ["global-children-members gcm"],
        "where": [
          ["eq", "_S.id", "gcm.id"]
        ]
      }]
    ]
  ],
  "foo": [
    ["add", "children-member"
      ["apply-hops", "bar", {
        "datasets": ["global-children-members gcm"],
        "where": [
          ["eq", "_S.id", "gcm.id"]
        ]
      }]
    ],
    ["add", "children",
      ["dict", "children",
        ["apply-hops", "child", {
          "datasets": ["parent-children-relations pcr"],
          "where": [
            ["eq", "_S.foo", "pcr.bar""]
          ]
        }]
      ]
    ]
  ]
}

} }

问题就变成了如何编写适用于层次结构中n级的递归函数。

谢谢！