Digger protocol (digger v3.3.0)

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Documentation for Digger Protocol

Summary

Types

t()

All the types that implement this protocol.

Functions

'Atomize' a valid Types.data_type according to the protocol implementation

Camel case a valid Types.data_type according to the protocol implementation

'Dasherize' a valid Types.data_type according to the protocol implementation

Flatten a nested map into a single-level map whose keys are the separator-joined paths (default separator ".") to each leaf value

Lower case first letter of a valid Types.data_type according to the protocol implementation

snake_case a valid Types.data_type according to the protocol implementation

'Stringify' a valid Types.data_type according to the protocol implementation

Rebuild a nested map from a flattened one by splitting each string key on the separator (default ".")

Upper case the first letter of a valid Types.data_type according to the protocol implementation

Types

t()

@type t() :: term()

All the types that implement this protocol.

Functions

atomize(data_type, opts \\ [type: :key, key_transform: :atomize, value_transform: :none])

'Atomize' a valid Types.data_type according to the protocol implementation

By default, atomizing a string that has no corresponding existing atom creates a new one via String.to_atom/1, which is safe for trusted input but can exhaust the atom table if used on untrusted/external data (atoms are never garbage collected).

Pass existing: true to atomize via String.to_existing_atom/1 instead: strings that already have a matching atom are converted as usual, and strings that don't are left as the original string rather than raising or creating a new atom.

Examples

iex> Digger.atomize(%{"user" => %{"name" => "Ada"}})
%{user: %{name: "Ada"}}

iex> Digger.atomize(%{"ok" => 1, "no_such_atom_xyz" => 2}, existing: true)
%{:ok => 1, "no_such_atom_xyz" => 2}

camel_case(data_type, opts \\ [type: :key, key_transform: :upper, value_transform: :none])

Camel case a valid Types.data_type according to the protocol implementation

The default is UpperCamelCase; pass key_transform: :lower for the lowerCamelCase convention used in JavaScript APIs.

Examples

iex> Digger.camel_case(%{user_id: 1})
%{UserId: 1}

iex> Digger.camel_case(
...>   %{user_id: 1},
...>   type: :key, key_transform: :lower, value_transform: :none
...> )
%{userId: 1}

dasherize(data_type, opts \\ [type: :key, key_transform: :dasherize, value_transform: :none])

'Dasherize' a valid Types.data_type according to the protocol implementation

Examples

iex> Digger.dasherize(%{"foo_bar" => 1})
%{"foo-bar" => 1}

flatten(data_type, opts \\ [separator: "."])

Flatten a nested map into a single-level map whose keys are the separator-joined paths (default separator ".") to each leaf value

Path keys are converted to strings with to_string/1, so keys must implement String.Chars (atoms, strings, and numbers all do). Structs (including calendar types like Date), lists, and empty maps are leaf values — they are never descended into. Non-map input passes through unchanged.

Examples

iex> Digger.flatten(%{a: %{b: 1}})
%{"a.b" => 1}

iex> Digger.flatten(%{"user" => %{"id" => 7}}, separator: "/")
%{"user/id" => 7}

lowercase_first(data_type, opts \\ [type: :key, key_transform: :lower, value_transform: :none])

Lower case first letter of a valid Types.data_type according to the protocol implementation

Examples

iex> Digger.lowercase_first(%{"FooBar" => 1})
%{"fooBar" => 1}

snake_case(data_type, opts \\ [type: :key, key_transform: :snake, value_transform: :none])

snake_case a valid Types.data_type according to the protocol implementation

Only keys are transformed by default — string values pass through unchanged.

Examples

iex> Digger.snake_case(%{"userId" => 1, "displayName" => "johnDoe"})
%{"user_id" => 1, "display_name" => "johnDoe"}

stringify(data_type, opts \\ [type: :key, key_transform: :stringify, value_transform: :none])

'Stringify' a valid Types.data_type according to the protocol implementation

Examples

iex> Digger.stringify(%{user: %{name: "Ada"}})
%{"user" => %{"name" => "Ada"}}

unflatten(data_type, opts \\ [separator: "."])

Rebuild a nested map from a flattened one by splitting each string key on the separator (default ".")

The exact inverse of Digger.flatten/2 for the maps it produces: unflatten(flatten(map)) == map whenever map's keys are strings that don't contain the separator. Maps with atom or number keys round-trip to their string-keyed equivalent, since flatten/2 converts path keys to strings. Non-string keys are kept in place, never split. Non-map input passes through unchanged.

Examples

iex> Digger.unflatten(%{"a.b" => 1, "a.c" => 2})
%{"a" => %{"b" => 1, "c" => 2}}

iex> Digger.unflatten(%{"user/id" => 7}, separator: "/")
%{"user" => %{"id" => 7}}

upcase_first(data_type, opts \\ [type: :key, key_transform: :upper, value_transform: :none])

Upper case the first letter of a valid Types.data_type according to the protocol implementation

Examples

iex> Digger.upcase_first(%{"fooBar" => 1})
%{"FooBar" => 1}