Decodes YAML strings into Elixir data structures or AST.

Options

• :detailed - controls whether to return AST with metadata or simplified data (default: false)

  • false (default) - returns plain Elixir maps, lists, and primitives
  • true - returns full AST with metadata (line numbers, column numbers, tags)

• :return - selects which decoded YAML documents are returned. It may be one of :auto, :first_document or :all_documents.

  • :auto (default) - automatically determines the return format based on the input. Single-document input returns the decoded value directly single document (map or list), while multi-document input returns a list with all decoded documents.
  • :first_document - returns only the first decoded YAML document.
  • :all_documents - returns all decoded YAML documents as a list.

• :enable_merge - controls YAML merge key behavior (default: true)

  • true (default) - processes << as merge keys (YAML 1.1 behavior)
  • false - treats << as regular keys (YAML 1.2+ behavior)

• :atomize_keys - controls whether map keys are converted to atoms (default: false)

  • false (default) - keeps all keys as binary strings
  • :safe - converts keys to atoms only if the atom already exists in the atom table
  • true - converts all keys to atoms (only use for trusted input)

• :yamerl_opts - list of additional options passed directly to :yamerl_constr (default: []). Note: :str_node_as_binary and :detailed_constr are always set internally and should not be passed here.

  • {:schema, :failsafe | :json | :core | :yaml11} - YAML schema for type resolution (default: :core)

  • {:node_mods, [module()]} - extra modules for custom node types (default: [])
  • {:keep_duplicate_keys, boolean()} - preserve duplicate map keys (default: false)

Examples

iex> YAML.decode("- a: 1")
{:ok, [[%{"a" => 1}]]}

iex> YAML.decode("a: 1", return: :first_document)
{:ok, %{"a" => 1}}

iex> YAML.decode("a: 1", yamerl_opts: [{:schema, :core}, {:map_node_format, :map}])
{:ok, [%{"a" => 1}]}