This is a Go implementation of JSONPath introduced in:

https://goessner.net/articles/JsonPath/

as well as JSON path expressions of the form:

/key1/index/*/key2

with the following exceptions:

• If a path component is a it should be a valid identifier or number. If that is not the case, it should be a string literal, that is, quoted.

  For example: $.dash-key is invalid. You must quote it: $."dash-key" or $.'dash-key'.

• Function and method calls must have a possibly empty argument list.

  For example: length(@) and @.length() are valid, but @.length will look for a length key under the current node.

• Decimals cannot start with a period, that is .5 is invalid. Use 0.5 instead. Decimal starting with a period confuses the lexer.

• Regular expressions are not supported yet.

First, compile the path:

path, err:= gojsonpath.Parse("$.store.book[*].author")

Then you can use:

results, err:= gojsonpath.Find(doc,path)

or you can capture the full-path for the nodes that match:

result:=make([]any,0)
err := gojsonpath.Search(doc,path,func(elem []gojsonpath.Element) {
  result=append(result,elem[len(elem)-1].Node)
})

You can use the simple path parser to compile '/' separated paths:

path, err := gojsonpath.Parse("/store/book/*/author")

Simple paths must start with '/', and may contain object keys, array indexes, or '*' to match anything, separated by '/'.

This implementation of JSONPath works with a flexible document model. To use the familiar map[string]any implementation of JSON, use:

var jsonDoc any
json.Unmarshal(jsonBytes,&jsonDoc)
doc := gojsonpath.MapModel{Doc:jsonDoc}

The DocModel interface provides a view of the underlying model, so the JSON document does not have to be a map[string]any. Any hierarchical document model supporting key-value, array, and value nodes can be used.