ruby/red-arrow-format/lib/arrow-format/schema.rb

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#
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module ArrowFormat
  class Schema
    attr_reader :fields
    attr_reader :metadata
    attr_reader :message_metadata
    def initialize(fields, metadata: nil, message_metadata: nil)
      @fields = fields
      @metadata = metadata
      @message_metadata = message_metadata
    end

    def [](name_or_index)
      case name_or_index
      when Integer
        @fields[name_or_index]
      when Symbol
        name_to_field[name_or_index.to_s]
      else
        name_to_field[name_or_index.to_str]
      end
    end

    def to_flatbuffers
      fb_schema = FB::Schema::Data.new
      fb_schema.endianness = FB::Endianness::LITTLE
      fb_schema.fields = fields.collect(&:to_flatbuffers)
      fb_schema.custom_metadata = FB.build_custom_metadata(@metadata)
      # fb_schema.features = @features
      fb_schema
    end

    private
    def name_to_field
      @name_to_field ||= build_name_to_field
    end

    def build_name_to_field
      name_to_field = {}
      @fields.each do |field|
        name_to_field[field.name] = field
      end
      name_to_field
    end
  end
end