richardjennings/keypath

map keys to structure

KeyPath

What

Transforms map[string]string{} into interface{} using the map keys as definitions of structure.

Semantics

Numeric keys indicate a list:

map[string]string{
    "1": "1",
}
=> 
[]interface{}{
    1: "1",
}

Non-Numeric keys specify a map:

map[string]string{
    "a": "1",
}
=> 
map[string]interface{}{
    "a": "1",
}

If Non-Numeric and Numeric keys are mixed, the Numeric Keys are treated as Non-Numeric:

map[string]string{
    "0": "1",
    "a": "2",
}
=> 
map[string]interface{}{
    "0": "1",
    "a": "2",
}

Types can be nested arbitrarily:

map[string]string{
    "0.a.0": "1",
    "0.a.1": "2",
    "0.a.2": "3",
    "0.b.c": "4",
    "a.b.c": "5",
}
=> 
map[string]interface{}{
    "0": map[string]interface{}{
        "a": []interface{}{
            0: "1",
            1: "2",
            2: "3",
        },
        "b": map[string]interface{}{
            "c": "4",
        },
    },
    "a": map[string]interface{}{
        "b": map[string]interface{}{
            "c": "5",
        },
    },
}
note: the "a.b.c" key changes the structure from a list to a map.

Errors

An error is returned if a type previously specified is changed, for example:

map[string]string{
    "a":   "1",
    "a.b": "2",
}

results in a errors.New("type mismatch")