Spectral.Type (Spectral v0.12.0)

Elixir wrapper for the Erlang :spectra_type module.

Provides functions for inspecting sp_type() values. These are most useful inside Spectral.Codec callbacks, where the sp_type argument carries the instantiation node from the type traversal.

Advanced integrations

This module is intended for advanced integrations, such as building custom web framework plugins or other tooling on top of Spectral. Most applications will not need to use it directly.

Summary

Functions

type_args(sp_type)

Returns the concrete type-variable bindings for a generic sp_type() node.

Functions

type_args(sp_type)

@spec type_args(term()) :: [term()]

Returns the concrete type-variable bindings for a generic sp_type() node.

When a codec is invoked during type traversal for a parameterised type such as MapSet.t(integer()) or dict:dict(binary(), float()), the sp_type argument is the reference node and type_args/1 returns the list of concrete type arguments in declaration order.

Returns [] when the type has no type variables, or when the codec is invoked directly from a Spectral.encode/decode/schema entry point rather than from mid-traversal dispatch.

Example

# In a codec for MapSet.t(elem):
def encode(:json, mod, {:type, :t, 1}, %MapSet{} = ms, sp_type, _params, _config) do
  case Spectral.Type.type_args(sp_type) do
    [elem_type] ->
      # recursively encode each element using elem_type
    [] ->
      # no type info available, fall back to plain list
      {:ok, MapSet.to_list(ms)}
  end
end