Class: Lutaml::Model::MappingRule

Inherits:
Object
  • Object
show all
Includes:
DeepDupable
Defined in:
lib/lutaml/model/mapping/mapping_rule.rb

Direct Known Subclasses

KeyValue::MappingRule, Xml::MappingRule

Constant Summary collapse

ALLOWED_OPTIONS = 
{
  render_nil: %i[
    omit
    as_nil
    as_blank
    as_empty
  ],
  render_empty: %i[
    omit
    as_empty
    as_blank
    as_nil
  ],
}.freeze
EMPTY_TRANSFORMERS =

Frozen empty array for the common case of no transformers

[].freeze
TRANSFORM_DISPATCH =

Verdict for handle_transform_method's dispatch, computed once per (rule, attribute) — both are static after definition, but rules may be frozen, so the memo lives at class level keyed on identity. :assign — no transformer runs on deserialize (fast path); :import — hash/proc transformers go through ImportTransformer.

{}.compare_by_identity

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, to:, to_instance: nil, as_attribute: nil, render_nil: false, render_default: false, render_empty: false, treat_nil: :nil, treat_empty: :empty, treat_omitted: :nil, with: {}, attribute: false, delegate: nil, root_mappings: nil, polymorphic: {}, polymorphic_map: {}, transform: {}, value_map: {}) ⇒ MappingRule

Returns a new instance of MappingRule.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 55

def initialize(
  name,
  to:,
  to_instance: nil,
  as_attribute: nil,
  render_nil: false,
  render_default: false,
  render_empty: false,
  treat_nil: :nil,
  treat_empty: :empty,
  treat_omitted: :nil,
  with: {},
  attribute: false,
  delegate: nil,
  root_mappings: nil,
  polymorphic: {},
  polymorphic_map: {},
  transform: {},
  value_map: {}
)
  @name = name
  @to = to
  # Dynamic symbol built per call allocated ~10% of parse objects on
  # attribute-heavy documents; `to` is immutable, so build it once.
  @setter_name = :"#{to}="
  @to_instance = to_instance
  @as_attribute = as_attribute
  @render_nil = render_nil
  @render_default = render_default
  @render_empty = render_empty
  @treat_nil = treat_nil
  @treat_empty = treat_empty
  @treat_omitted = treat_omitted
  @custom_methods = with
  @attribute = attribute
  @delegate = delegate
  @root_mappings = root_mappings
  @polymorphic = polymorphic
  @polymorphic_map = polymorphic_map
  @transform = transform

  # Cache whether this rule needs the full deserialize chain.
  # Over 95% of rules are "simple" (no custom method, no delegate).
  @needs_full_deserialize = has_custom_method_for_deserialization? || !!delegate

  # Only calculate default_value_map if value_map is not fully provided
  if value_map.empty? || !value_map[:from] || !value_map[:to]
    # Build value_map by starting with defaults from render_nil/render_empty,
    # then overlaying user-provided value_map entries on top.
    # User-provided value_map entries take PRECEDENCE over computed defaults.
    # This ensures that value_map: { to: { empty: :empty } } overrides
    # the default render_empty: false → :omitted behavior.
    vm = {
      from: (value_map[:from] || {}).dup,
      to: (value_map[:to] || {}).dup,
    }
    defaults = default_value_map
    vm[:from] = defaults[:from].merge(vm[:from])
    vm[:to] = defaults[:to].merge(vm[:to])
    @value_map = vm
  else
    # Complete value_map provided (e.g., from deep_dup), use it directly.
    @value_map = value_map
  end

  # Freeze value_map and its inner hashes — they are never mutated after
  # construction, and downstream code reads them on every serialization.
  @value_map[:from].freeze
  @value_map[:to].freeze
  @value_map.freeze

  # The :from treatment flags are read on every rule application of
  # every parse; they are static once @value_map is final. The three
  # Hash#[] chains per value used to cost 1.4 M value_map calls per
  # ISO-13849 parse.
  from_map = @value_map[:from]
  @treat_nil_flag = from_map[:nil] != :omitted
  @treat_empty_flag = from_map[:empty] != :omitted
  @treat_omitted_flag = from_map[:omitted] != :omitted
end

Instance Attribute Details

#as_attribute ⇒ Object (readonly)

Returns the value of attribute as_attribute.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def as_attribute
  @as_attribute
end

#attribute ⇒ Object (readonly) Also known as: attribute?

Returns the value of attribute attribute.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def attribute
  @attribute
end

#custom_methods ⇒ Object (readonly)

Returns the value of attribute custom_methods.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def custom_methods
  @custom_methods
end

#delegate ⇒ Object (readonly)

Returns the value of attribute delegate.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def delegate
  @delegate
end

#format ⇒ Object (readonly)

Returns the value of attribute format.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def format
  @format
end

#name ⇒ Object (readonly) Also known as: from

Returns the value of attribute name.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def name
  @name
end

#polymorphic ⇒ Object (readonly)

Returns the value of attribute polymorphic.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def polymorphic
  @polymorphic
end

#polymorphic_map ⇒ Object (readonly)

Returns the value of attribute polymorphic_map.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def polymorphic_map
  @polymorphic_map
end

#render_default ⇒ Object (readonly) Also known as: render_default?

Returns the value of attribute render_default.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def render_default
  @render_default
end

#render_empty ⇒ Object (readonly)

Returns the value of attribute render_empty.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def render_empty
  @render_empty
end

#render_nil ⇒ Object (readonly)

Returns the value of attribute render_nil.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def render_nil
  @render_nil
end

#to ⇒ Object (readonly)

Returns the value of attribute to.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def to
  @to
end

#to_instance ⇒ Object (readonly)

Returns the value of attribute to_instance.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def to_instance
  @to_instance
end

#transform ⇒ Object (readonly)

Returns the value of attribute transform.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def transform
  @transform
end

#treat_empty ⇒ Object (readonly)

Returns the value of attribute treat_empty.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def treat_empty
  @treat_empty
end

#treat_nil ⇒ Object (readonly)

Returns the value of attribute treat_nil.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def treat_nil
  @treat_nil
end

#treat_omitted ⇒ Object (readonly)

Returns the value of attribute treat_omitted.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 6

def treat_omitted
  @treat_omitted
end

Class Method Details

.transform_dispatch(rule, attr) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 427

def self.transform_dispatch(rule, attr)
  per_attr = TRANSFORM_DISPATCH[rule]
  if per_attr.nil?
    per_attr = {}.compare_by_identity
    TRANSFORM_DISPATCH[rule] = per_attr
  end
  verdict = per_attr[attr]
  return verdict if verdict

  rule_transform = rule.transform
  # NB: `::Hash` — inside Lutaml::Model the bare constant `Hash` is
  # the hash-format adapter class, so a plain is_a?(Hash) is always
  # false here (the original dispatch shared that shadow and never
  # took the hash-transform branch).
  rule_has = rule_transform.is_a?(Class) ||
    (rule_transform.is_a?(::Hash) && !rule_transform.empty?)
  attr_transform = attr&.transform
  attr_has = attr_transform &&
    (attr_transform.is_a?(Class) ||
     (attr_transform.is_a?(::Hash) && !attr_transform.empty?))

  verdict = if !rule_has && !attr_has
              :assign
            elsif rule.get_transformers(attr).any? do |t|
              t.is_a?(Class) && t < Lutaml::Model::ValueTransformer
            end
              :assign
            else
              :import
            end
  per_attr[attr] = verdict
  verdict
end

Instance Method Details

#can_transform_to?(attribute, format) ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 413

def can_transform_to?(attribute, format)
  get_transformers(attribute).any? { |t| t.can_transform?(:to, format) }
end

#custom_method_only? ⇒ Boolean

Static per rule: placeholder __name__ targets and inferred custom-method targets without an attribute type never change — the applier asked this per element and paid two to_s strings each time (240k allocations on the ISO-13849 serialize profile). Rules may be frozen, so no per-instance memo: one to_s instead of two is the frozen-safe diet.

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 331

def custom_method_only?
  name = attribute_name.to_s
  (name.start_with?("__") && name.end_with?("__")) ||
    (has_custom_methods? && attribute_type.nil?)
end

#deep_dup ⇒ Object

Raises:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 361

def deep_dup
  raise NotImplementedError, "Subclasses must implement `deep_dup`."
end

#default_value_map(options = {}) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 136

def default_value_map(options = {})
  render_nil_as = render_as(:render_nil, :omitted, options)
  render_empty_as = render_as(:render_empty, :empty, options)

  treat_nil_as = treat_as(:treat_nil, :nil, options)
  treat_empty_as = treat_as(:treat_empty, :empty, options)
  treat_omitted_as = treat_as(:treat_omitted, :nil, options)

  {
    from: { omitted: treat_omitted_as, nil: treat_nil_as,
            empty: treat_empty_as },
    to: { omitted: :omitted, nil: render_nil_as, empty: render_empty_as },
  }
end

#deserialize(model, value, attributes, mapper_class = nil, context = nil) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 314

def deserialize(model, value, attributes, mapper_class = nil,
context = nil)
  if @needs_full_deserialize
    handle_custom_method(model, value, mapper_class, context) ||
      handle_delegate(model, value, attributes) ||
      handle_transform_method(model, value, attributes, context)
  else
    handle_transform_method(model, value, attributes, context)
  end
end

#eql?(other) ⇒ Boolean Also known as: ==

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 353

def eql?(other)
  other.class == self.class &&
    instance_variables.all? do |var|
      instance_variable_get(var) == other.instance_variable_get(var)
    end
end

#get_transformers(attribute) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 461

def get_transformers(attribute)
  # Fast path: most rules have no transforms at all
  rule_transform = transform
  attr_transform = attribute&.transform

  if !rule_transform && !attr_transform
    return EMPTY_TRANSFORMERS
  end

  # Build transformer list only when needed
  transformers = []
  transformers << rule_transform if rule_transform
  transformers << attr_transform if attr_transform
  transformers.select! { |t| t.is_a?(Class) }
  transformers.freeze
end

#has_custom_method_for_deserialization? ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 341

def has_custom_method_for_deserialization?
  !custom_methods.empty? && custom_methods[:from]
end

#has_custom_method_for_serialization? ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 337

def has_custom_method_for_serialization?
  !custom_methods.empty? && custom_methods[:to]
end

#has_items?(value) ⇒ Boolean

Check if value is a non-empty collection

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 228

def has_items?(value)
  return false if value.nil? || Utils.uninitialized?(value)
  return false unless value.is_a?(String) || value.is_a?(Array) || value.is_a?(Hash)

  !value.empty?
end

#multiple_mappings? ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 345

def multiple_mappings?
  name.is_a?(Array)
end

#mutated_collection?(value, instance) ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 218

def mutated_collection?(value, instance)
  return false if value.nil? || Utils.uninitialized?(value)
  return false unless value.is_a?(Array) || value.is_a?(Lutaml::Model::Collection)
  return false if value.empty? # Empty collection is still default

  # If it's a non-empty collection and marked as using_default, it was mutated
  instance.is_a?(Lutaml::Model::Serialize) && instance.using_default?(to)
end

#name_strings ⇒ Object

Normalized name spellings for matching, computed once. The name is fixed after construction (attr_reader only), so the memo is safe. Hot loops used to redo Array(name).map(&:to_s) per element.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 51

def name_strings
  @name_strings ||= Array(name).map(&:to_s).freeze
end

#polymorphic_mapping? ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 272

def polymorphic_mapping?
  polymorphic_map && !polymorphic_map.empty?
end

#raw_mapping? ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 349

def raw_mapping?
  name == Constants::RAW_MAPPING_KEY
end

#raw_value_map ⇒ Object

Raw value_map hash access (for compiled rules). Use value_map(key, options) for individual lookups with overrides.



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 367

def raw_value_map
  @value_map
end

#render?(value, instance = nil, options = {}) ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 179

def render?(value, instance = nil, options = {})
  if invalid_value?(value, options)
    false
  # FIXED: Check if collection was mutated after initialization
  # A non-empty collection initialized with default [] should render if mutated
  # This handles the case where collection is mutated with << or custom methods
  elsif mutated_collection?(value, instance)
    true
  elsif instance.is_a?(Lutaml::Model::Serialize) && instance.using_default?(to)
    render_default? || RenderPolicy.derived_attribute_for?(instance, to)
  else
    true
  end
end

#render_as(key, default_value, options = {}) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 151

def render_as(key, default_value, options = {})
  value = public_send(key)
  value = options[key] if value.nil?

  if value == true
    key.to_s.split("_").last.to_sym
  elsif value == false
    :omitted
  elsif value
    {
      as_empty: :empty,
      as_blank: :blank,
      as_nil: :nil,
      omit: :omitted,
    }[value]
  else
    default_value
  end
end

#render_empty?(options = {}) ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 246

def render_empty?(options = {})
  value_map(:to, options)[:empty] != :omitted
end

#render_nil?(options = {}) ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 242

def render_nil?(options = {})
  value_map(:to, options)[:nil] != :omitted
end

#render_omitted?(options = {}) ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 250

def render_omitted?(options = {})
  value_map(:to, options)[:omitted] != :omitted
end

#render_value_for(value) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 206

def render_value_for(value)
  if value.nil?
    value_for_option(value_map(:to)[:nil])
  elsif Utils.empty?(value)
    value_for_option(value_map(:to)[:empty], value)
  elsif Utils.uninitialized?(value)
    value_for_option(value_map(:to)[:omitted])
  else
    value
  end
end

#serialize(model, parent = nil, doc = nil, context = nil) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 286

def serialize(model, parent = nil, doc = nil, context = nil)
  if custom_methods[:to]
    to_method = custom_methods[:to]
    # lutaml-model#550: custom methods may declare a fourth
    # context parameter to receive the options passed to `to_*`.
    if model.method(to_method).parameters.size >= 4
      model.public_send(to_method, model, parent, doc, context)
    else
      model.public_send(to_method, model, parent, doc)
    end
  else
    value = to_value_for(model)

    # Handle Reference types - extract the key for serialization
    # This ensures references serialize as their key, not the resolved object
    if value.is_a?(Lutaml::Model::Type::Reference)
      value = value.key
    elsif value.is_a?(Array)
      # Handle collection of references
      value = value.map do |v|
        v.is_a?(Lutaml::Model::Type::Reference) ? v.key : v
      end
    end

    value
  end
end

#to_value_for(model) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 276

def to_value_for(model)
  if delegate
    model.public_send(delegate).public_send(to)
  else
    return if to.nil?

    model.public_send(to)
  end
end

#transform_value(attribute, value, read_method, format) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 388

def transform_value(attribute, value, read_method, format)
  # Fast path: no transforms at all (covers 95%+ of rules)
  # transform defaults to {}, so check for actual content, not just truthiness
  has_rule_transform = transform.is_a?(Class)
  has_attr_transform = attribute&.transform.is_a?(Class)
  return value unless has_rule_transform || has_attr_transform

  transformers = get_transformers(attribute)
  transformers = transformers.reverse if read_method == :to

  return value if transformers.empty? || transformers.none? do |t|
    t.can_transform?(read_method, format)
  end

  # Apply transformers in sequence
  transformers.reduce(value) do |v, transformer|
    if transformer.is_a?(Class) && transformer < Lutaml::Model::ValueTransformer
      # Call class method directly: NameTransformer.from(value, :json)
    else
      # Hash/proc transformer
    end
    transformer.public_send(read_method, v, format)
  end
end

#treat?(value) ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 194

def treat?(value)
  if value.nil?
    treat_nil?
  elsif Utils.uninitialized?(value)
    treat_omitted?
  elsif Utils.empty?(value)
    treat_empty?
  else
    true
  end
end

#treat_as(key, default_value, options = {}) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 171

def treat_as(key, default_value, options = {})
  public_send(key) || options[key] || default_value
end

#treat_empty?(options = {}) ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 260

def treat_empty?(options = {})
  return @treat_empty_flag unless options[:nil] || options[:empty] || options[:omitted]

  value_map(:from, options)[:empty] != :omitted
end

#treat_nil?(options = {}) ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 254

def treat_nil?(options = {})
  return @treat_nil_flag unless options[:nil] || options[:empty] || options[:omitted]

  value_map(:from, options)[:nil] != :omitted
end

#treat_omitted?(options = {}) ⇒ Boolean

Returns:



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 266

def treat_omitted?(options = {})
  return @treat_omitted_flag unless options[:nil] || options[:empty] || options[:omitted]

  value_map(:from, options)[:omitted] != :omitted
end

#value_for_option(option, empty_value = nil) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 235

def value_for_option(option, empty_value = nil)
  return nil if option == :nil
  return empty_value || "" if option == :empty

  Lutaml::Model::UninitializedClass.instance
end

#value_map(key, options = {}) ⇒ Object 



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# File 'lib/lutaml/model/mapping/mapping_rule.rb', line 371

def value_map(key, options = {})
  # Fast path: when no overrides, return cached value directly
  # Callers MUST NOT mutate the returned hash
  if !options[:nil] && !options[:empty] && !options[:omitted]
    return @value_map[key]
  end

  # Slow path: merge overrides (only when options have actual values)
  overrides = {
    nil: options[:nil],
    empty: options[:empty],
    omitted: options[:omitted],
  }.compact

  @value_map[key].merge(overrides)
end