Construct

v2.1.10

Construct v2.1.10 Construct.Type behaviour View Source

Type-coercion module, originally copied and modified from Ecto.Type and behaviour to implement your own types.

Defining custom types 

defmodule CustomType do
  @behaviour Construct.Type

  def cast(value) do
    {:ok, value}
  end
end

Link to this section Summary

Types

builtin()
cast_ret()
custom()
t()

Functions

cast(type, term)

Behaves like cast/3, but without options provided to nested types

cast(type, term, opts)

Casts a value to the given type

primitive?(type)

Checks if we have a primitive type

spec(type)

Returns typespec AST for given type

typeof(term)

Returns typespec AST for given term

Callbacks

cast(term)

Casts the given input to the custom type

Link to this section Types

Link to this type builtin() View Source 
builtin() ::
  :integer
  | :float
  | :boolean
  | :string
  | :binary
  | :pid
  | :reference
  | :decimal
  | :utc_datetime
  | :naive_datetime
  | :date
  | :time
  | :any
  | :array
  | {:array, t()}
  | :map
  | {:map, t()}
  | :struct
Link to this type cast_ret() View Source 
cast_ret() :: {:ok, term()} | {:error, term()} | :error

Link to this section Functions

Link to this function cast(type, term) View Source 
cast(t(), term()) :: cast_ret() | any()

Behaves like cast/3, but without options provided to nested types.

Link to this function cast(type, term, opts) View Source 
cast(t(), term(), options) :: cast_ret() | any()
when options: [{:make_map, boolean()}]

Casts a value to the given type.

iex> cast(:any, "whatever")
{:ok, "whatever"}

iex> cast(:any, nil)
{:ok, nil}
iex> cast(:string, nil)
:error

iex> cast(:integer, 1)
{:ok, 1}
iex> cast(:integer, "1")
{:ok, 1}
iex> cast(:integer, "1.0")
:error

iex> cast(:float, 1.0)
{:ok, 1.0}
iex> cast(:float, 1)
{:ok, 1.0}
iex> cast(:float, "1")
{:ok, 1.0}
iex> cast(:float, "1.0")
{:ok, 1.0}
iex> cast(:float, "1-foo")
:error

iex> cast(:boolean, true)
{:ok, true}
iex> cast(:boolean, false)
{:ok, false}
iex> cast(:boolean, "1")
{:ok, true}
iex> cast(:boolean, "0")
{:ok, false}
iex> cast(:boolean, "whatever")
:error

iex> cast(:string, "beef")
{:ok, "beef"}
iex> cast(:binary, "beef")
{:ok, "beef"}

iex> cast(:decimal, Decimal.new(1.0))
{:ok, Decimal.new(1.0)}
iex> cast(:decimal, Decimal.new("1.0"))
{:ok, Decimal.new(1.0)}
iex> cast(:decimal, 1.0)
{:ok, Decimal.new(1.0)}
iex> cast(:decimal, "1.0")
{:ok, Decimal.new(1.0)}

iex> cast({:array, :integer}, [1, 2, 3])
{:ok, [1, 2, 3]}
iex> cast({:array, :integer}, ["1", "2", "3"])
{:ok, [1, 2, 3]}
iex> cast({:array, :string}, [1, 2, 3])
:error
iex> cast(:string, [1, 2, 3])
:error
Link to this function primitive?(type) View Source 
primitive?(t()) :: boolean()

Checks if we have a primitive type.

iex> primitive?(:string)
true
iex> primitive?(Another)
false

iex> primitive?({:array, :string})
true
iex> primitive?({:array, Another})
true

iex> primitive?([Another, {:array, :integer}])
false
Link to this function spec(type) View Source 
spec(t()) :: Macro.t()

Returns typespec AST for given type

iex> spec([CommaList, {:array, :integer}]) |> Macro.to_string() “list(:integer)”

iex> spec({:array, :string}) |> Macro.to_string() “list(String.t())”

iex> spec({:map, CustomType}) |> Macro.to_string() “%{optional(term) => CustomType.t()}”

iex> spec(:string) |> Macro.to_string() “String.t()”

iex> spec(CustomType) |> Macro.to_string() “CustomType.t()”

Link to this function typeof(term) View Source 
typeof(t()) :: Macro.t()

Returns typespec AST for given term

iex> typeof(nil) |> Macro.to_string() “nil”

iex> typeof(1.42) |> Macro.to_string() “float()”

iex> typeof(“string”) |> Macro.to_string() “String.t()”

iex> typeof(CustomType) |> Macro.to_string() “CustomType.t()”

iex> typeof(&NaiveDateTime.utc_now/0) |> Macro.to_string() “NaiveDateTime.t()”

Link to this section Callbacks

Link to this callback cast(term) View Source 
cast(term()) :: cast_ret()

Casts the given input to the custom type.