ExCraft

Helper tool to define Elixir structures and constructors.

• Gives some compile-time control of types, required, default and enforced values.
• Generates constructor &new/1 for your data structure.

Usage

Define your structures like a BOSS:

defmodule ExCraft.Car do
  require ExCraft
  ExCraft.craft [
    %ExCraft.Field{name: :brand,  type: :string,        required: false,   default: "custom",  enforce: false},
    %ExCraft.Field{name: :year,   type: :pos_integer,   required: true,    default: nil,       enforce: true},
    %ExCraft.Field{name: :used,   type: :boolean,       required: false,   default: true,      enforce: false},
  ]
end

Examples

Use structure as is, or use &new/1 constructor to perform some implicit types conversions and checks. It's very useful in Phoenix plugs/controllers because request parameters are usually passed as maps with strings as keys and values.

iex> alias ExCraft.Car
ExCraft.Car
iex> %Car{year: 1990}
%Car{brand: "custom", used: true, year: 1990}
iex> Car.new(%{"year" => "1990"})
%Car{brand: "custom", used: true, year: 1990}
iex> Car.new(%{year: "1990"})
%Car{brand: "custom", used: true, year: 1990}
iex> Car.new([year: "1990"])
%Car{brand: "custom", used: true, year: 1990}
iex> Car.new(%{"year" => 1990.0})
%Car{brand: "custom", used: true, year: 1990}
iex> Car.new(%Car{brand: "custom", used: true, year: 1990})
%Car{brand: "custom", used: true, year: 1990}
iex> Car.new(%{"year" => "1990.1"})
** (RuntimeError) Elixir.ExCraft.Car ExCraft error. Type of "1990.1" is not pos_integer. Error in field %ExCraft.Field{default: nil, enforce: true, name: :year, required: true, type: :pos_integer} of data source %{"year" => "1990.1"}.

Types

List of available types.

:atom
:binary
:string
:number
:pos_number
:non_neg_number
:integer
:pos_integer
:non_neg_integer
:float
:pos_float
:non_neg_float
:struct
:map
:list
:tuple
:keyword
:boolean

TODO

• add typespec generator
• add &new/1 macro that defines only constructor
• add macro to create constructor for Ecto model