This repository was inspired by mattyw's blog post Using go to unmarshal json lists with multiple types

To summarize the article, we are given a JSON string of the form:

{
    "things": [
        {
            "name": "Alice",
            "age": 37
        },
        {
            "city": "Ipoh",
            "country": "Malaysia"
        },
        {
            "name": "Bob",
            "age": 36
        },
        {
            "city": "Northampton",
            "country": "England"
        }
    ]
}

And our goal is to unmarshal it into a Go data structure. The article goes into more detail, and two solutions were proposed. A commenter came up with a third solution, and another commenter dustin proposed using his library called jsonpointer, which operates on the raw byte array of the json string, instead of unmarshalling first and then traversing the data structure.

I used Dustin's library, and to great avail, the only gotcha was that json strings were returned with the double quotes in them and some trailing spaces, but I made a little function that returned a slice of the original bytes:

func trimJsonBytes(toTrim []byte) []byte {
    // implementation found in solution.go
}

Here is the algorithm:

loop i:=0,1,2,...∞
  if  /things/i/name  is empty
    make a person
    append it to the person array

  else if /things/i/city is empty
    make a place
    append it to the places array

  else 
    end of array, break out of loop

end loop