ddql.md

Potential data language

This is a wishlist of how I want the query language to look. The only things on here that work right now are get s and get ns.

I haven't yet decided if I actually want to support sets due to how the indexing works through a hash. It would be cumbersome to try and pass a big value into dictdots in the query string.

Get

---

Get returns a specific object matching an exact query.

• s match a specific key, e.g. hello.goodbye would get "world" from:

  {
      "hello": {
          "goodbye": "world"
      },
  }

• n match specific index in a list. e.g. 0.hello would get "world" from:

  [
      {"hello": "world"},
  ]

• n match an integer key. e.g. 1.2 would get "why are you using int keys?" from:

  {
      1: {
          2: "why are you using int keys?",
      },   
  }

• nfn match a float key n.n, e.g. 100f04 gets "e" from {100.04: "e"}.
• ns match a numeric string n, e.g. 100s would get "e" from {"100": "e"}.
• {s} match a specific index in a set. e.g. {hello} would get "hello" from {"hello", "world"}. This seems somewhat useless.

Filter

---

Filter returns a list of objects that matched the query and an empty list if there were no matches.

Supports all get query args.

• [] means match any index in a list. Return any objects in list that match the query after the []. e.g. [].foo would get ["t", "bar"] from:

  [
      {"foo": "t"},
      {"foo": "bar"},
      {"no": "match"},
  ]

• {} match any key in a dictionary. Return any values that match the query after the {{}}. e.g. {}.sierra would get ["117", "034"] from:

  {
      "hello": {"sierra": "117"},
      "goodbye": {"sierra": "034"},
      "morning": {"no": "match"},
  }

• {,} match any index in a set. Return a set of values that match the query after the {{s}}. e.g. {,}.sierra would get [117, ] from:

  {
      {"sierra": 117},
      {"the fall of": "reach"},
  }

Exists

---

Uses the same logic as get, but returns a boolean instead of the value. Checks if the key exists rather than grabbing the value.

Must still return True even if the value is falsey.

e.g.

bob = {
    "sierra_117": False,
    "sandtrap": "",
    "endless": None,
}

assert DictDots.exists(bob, "sierra_117")
assert DictDots.exists(bob, "sandtrap")
assert DictDots.exists(bob, "endless")

should all pass.