Cobblestone

A better path to data

Experimental. Exploring leex, yecc, and data access.

Inspired by jq, JSONPath, and XPath.

%{
  "store" => %{
    "book" => [
      %{
        "category" => "reference",
        "author" => "Nigel Rees",
        "title" => "Sayings of the Century",
        "price" => 8.95
      },
      %{
        "category" => "fiction",
        "author" => "Evelyn Waugh",
        "title" => "Sword of Honour",
        "price" => 12.99
      },
      %{
        "category" => "fiction",
        "author" => "Herman Melville",
        "title" => "Moby Dick",
        "isbn" => "0-553-21311-3",
        "price" => 8.99
      },
      %{
        "category" => "fiction",
        "author" => "J. R. R. Tolkien",
        "title" => "The Lord of the Rings",
        "isbn" => "0-395-19395-8",
        "price" => 22.99
      }
    ],
    "bicycle" => %{
      "color" => "red",
      "price" => 19.95
    }
  }
}

XPath	JSONPath	Cobblestone	Result
/store/book/author	$.store.book[*].author	.store.book[].author	the authors of all books in the store
//author	$..author	..author	all authors
/store/*	$.store.*	.store	all things in store, which are some books and a red bicycle
/store//price	$.store..price	.store..price	the price of everything in the store.
//book[3]	$..book[2]	..book[2]	the third book
//book[last()]	$..book[(@.length-1)] $..book[-1:]	..book[-1]	the last book in order.
//book[position()<3]	$..book[0,1] $..book[:2]	..book[0,1] .store.book[:2]	the first two books
//book[isbn]	$..book[?(@.isbn)]	..book[isbn]	filter all books with isbn number
//book[price<10]	$..book[?(@.price<10)]	..book[price<10]	filter all books cheapier than 10
//*	$..*	.	all Elements in structure.

Installation

If available in Hex, the package can be installed by adding cobblestone to your list of dependencies in mix.exs:

def deps do
  [
    {:cobblestone, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/cobblestone.