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# File 'lib/method_struct.rb', line 4
def self.new(*fields, &block)
if fields.last.is_a?(Hash)
method_name = fields.last[:method_name]
fields = fields.take(fields.size - 1)
else
method_name = :call
end
Class.new do
singleton_class = (class << self; self; end)
singleton_class.instance_eval do
define_method(method_name) do |*field_values, &blk|
new(*field_values).send(method_name, &blk)
end
define_method(:[]) do |*args|
send(method_name, *args)
end
end
define_method(:[]) do |&blk|
send(method_name, &blk)
end
define_method(:initialize) do |*values|
if fields.size > 1 && values.size == 1 && values.first.is_a?(Hash)
fields.each do |field|
instance_variable_set("@#{field}", values.first[field])
end
else
fields.zip(values).each do |field, value|
instance_variable_set("@#{field}", value)
end
end
end
define_method(:==) do |other|
self.class == other.class && fields.all? do |field|
send(field) == other.send(field)
end
end
alias_method :eql?, :==
define_method(:hash) do
fields.map { |field| send(field).hash }.inject(&:^)
end
class_eval(&block) if block_given?
protected
fields.each do |field|
attr_reader(field)
end
end
end
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