cx

A library, written in Gleam, to help create data structures containing different data types and levels of nesting.

Note: This library is still being written!

Background

Gleam is statically typed, and has certain restrictions for certain data types. For example, a Dict in Gleam has this restriction on the keys and values:

...all the keys must be of the same type and all the values must be of the same type.

Lists have a similar restriction:

All elements of a list must be the same type

What if we want to represent more complicated, nested data structures as well? For example, here is a native data structure in Python:

data = {
    "settings": {
        "theme": "dark",
        "themes: ["light", "dark"]
    }
    "people": [
        {"Nicknames": ["Jane", "Jill"]},
    ]
}

Can we do this in Gleam? Yes, we can, with records. Records can also help us know the type of each object stored in the data structure, which is significant because runtime reflection is not available in Gleam.

This library was written to be used with an HTML templating engine, where pieces of the data structure are used to replace variables (e.g. @person.name)in the HTML.

Installing

gleam add cx

Usage

import cx

pub fn main() {
  let context =
    cx.dict()
    |> cx.add(
      "settings",
      cx.dict()
        |> cx.add_string("theme", "dark")
        |> cx.add_strings("themes", ["light", "dark"]),
    )
    |> cx.add_list("people", [
      cx.add_strings(cx.dict(), "Nicknames", ["Jane", "Jill"]),
    ])


    // Result: Ok(["light", "dark"])
    cx.get_strings(context, "settings.themes")
}

Further documentation can be found at https://hexdocs.pm/cx.

Development

gleam run   # Run the project
gleam test  # Run the tests