Javascript 树结构的转换

我正在为我的QueryBuilderJavaScript库（）解决一个问题

目标是从SQL语句填充生成器。为此，我使用WHERE子句转换为AST

现在我的问题是，我需要将这个AST（一种二叉树）转换为QueryBuilder的内部格式（我不知道技术名称）。但我很笨，找不到一个有效的算法

所以我来这里找一个擅长这个的人！我只需要主算法来转换数据结构，转换值和运算符格式不会有问题

注:

• 深度不受限制
• 组条件（当然）仅为和或
• 虽然规则的顺序并不重要，但应该予以保留

输入SQL为（测试用例）：

---

我想我已经成功了，下面是伪代码：

var out = {
  condition: null
  rules: []
}
var curr = out

function flatten(node, level)
  if node.operation = 'AND' or node.operation = 'OR' then
    if level > 0 and curr.condition != node.operation then
      curr.rules.push({
        condition: null
        rules: []
      })
      curr = curr.rules.end()
    end if

    curr.condition = node.operation

    level++;

    var next = curr
    flatten(node.right, level)

    curr = next
    flatten(node.left, level)
  else
    curr.rules.push({
      id: node.left.value
      operator: node.operation
      value: node.right.value
    })
  end if
end function

flatten(parsed, 0)

这是一个自调用的递归函数，当操作符在和和或之间变化时创建子组，而在展平左和右部分时在右子组中工作是一个小技巧

{
  left: {
    left: {
      left: {
        left: {
          value: 'name'
        },
        operation: 'LIKE',
        right: {
          value: 'Mistic%'
        },
      },
      operation: 'AND',
      right: {
        left: {
          value: 'price'
        },
        operation: 'BETWEEN',
        right: {
          value: [
            {
              value: 100
            },
            {
              value: 200
            }
          ]
        }
      }
    },
    operation: 'AND',
    right: {
      left: {
        left: {
          value: 'category'
        },
        operation: 'IN',
        right: {
          value: [
            {
              value: 1
            },
            {
              value: 2
            }
          ]
        }
      },
      operation: 'OR',
      right: {
        left: {
          value: 'parent'
        },
        operation: '<=',
        right: {
          value: 0
        }
      }
    }
  },
  operation: 'AND',
  right: {
    left: {
      value: 'id'
    },
    operation: 'is not',
    right: {
      value: null
    }
  }
}

{
  condition: 'AND',
  rules: [
    {
      id: 'name',
      operator: 'like',
      value: 'Mistic%'
    },
    {
      id: 'price',
      operator: 'between',
      value: [100, 200]
    },
    {
      condition: 'OR',
      rules: [
        {
          id: 'category',
          operator: 'in',
          value: [1, 2]
        },
        {
          id: 'parent',
          operator: 'less_or_equal',
          value: 0
        }
      ]
    },
    {
      id: 'id',
      operator: 'not_null',
      value: null
    }
  ]
}

var out = {
  condition: null
  rules: []
}
var curr = out

function flatten(node, level)
  if node.operation = 'AND' or node.operation = 'OR' then
    if level > 0 and curr.condition != node.operation then
      curr.rules.push({
        condition: null
        rules: []
      })
      curr = curr.rules.end()
    end if

    curr.condition = node.operation

    level++;

    var next = curr
    flatten(node.right, level)

    curr = next
    flatten(node.left, level)
  else
    curr.rules.push({
      id: node.left.value
      operator: node.operation
      value: node.right.value
    })
  end if
end function

flatten(parsed, 0)