BinData + Veritas

gistfile1.txt

class BinDataRelation < Veritas::Relation
  def initialize(klass, io)
    super([[:index, Integer]] + BinDataRelation.veritas_fields(klass), BinDataRelation.record_enumerator(klass, io))
  end

  protected
        
  def self.veritas_fields(klass)
    veritas_fields = []
    for field in klass.fields
      veritas_class = case field.prototype.obj_class.name
        when "BinData::String", "::PascalStringField" then String
        when -> n { n.to_s =~ /int/ } then Integer
        else
          raise "Unknown type: " + field.prototype.obj_class.to_s
      end
      veritas_fields << [ field.name_as_sym, veritas_class ]
    end
    veritas_fields
  end
        
  def self.record_enumerator(klass, io)
    Enumerator.new { |y|
      index = 0
      loop {
        begin
          record = klass.read(io)
        rescue EOFError
          raise StopIteration
        end
        row = [ index ] + klass.fields.collect { |f| record[f.name].value }
        index += 1
        y << row
      }
    }
  end
end