rubyx/lib/parfait/object.rb
2018-04-05 12:22:40 +03:00

128 lines
3.6 KiB
Ruby

# From a programmers perspective an object has hash like data (with instance variables as keys)
# and functions to work on that data.
# Only the object may access it's data directly.
# From an implementation perspective it is a chunk of memory with a type as the first
# word (instance of class Type).
# Objects are arranged or layed out (in memory) according to their Type
# every object has a Type. Type objects are immutalbe and may be reused for a group/class
# off objects.
# The Type of an object may change, but then a new Type is created
# The Type also defines the class of the object
# The Type is **always** the first entry (index 1) in an object
module Parfait
TYPE_INDEX = 1
class Object
def self.new *args
object = self.allocate
# have to grab the class, because we are in the ruby class not the parfait one
cl = Parfait.object_space.get_class_by_name( self.name.split("::").last.to_sym)
# and have to set the type before we let the object do anything. otherwise boom
object.set_type cl.instance_type
object.send :initialize , *args
object
end
# 1 -based index
def get_internal_word(index)
name = get_type().name_at(index)
return nil unless name
instance_variable_get("@#{name}".to_sym)
end
# 1 -based index
def set_internal_word(index , value)
return set_type(value) if( index == 1)
raise "not type #{@type.class}" unless @type.is_a?(Type)
name = @type.name_at(index)
#return value unless name
raise "object type (#{type}) has no name at index #{index} " unless name
instance_variable_set("@#{name}".to_sym, value)
value
end
def == other
self.object_id == other.object_id
end
# This is the crux of the object system. The class of an object is stored in the objects
# memory (as opposed to an integer that has no memory and so always has the same class)
#
# In RubyX we store the class in the Type, and so the Type is the only fixed
# data that every object carries.
def get_class()
l = get_type()
#puts "Type #{l.class} in #{self.class} , #{self}"
l.object_class()
end
# private
def set_type(type)
# puts "Type was set for #{self.class}"
raise "not type #{type.class} in #{self}" unless type.is_a?(Type)
@type = type
end
# so we can keep the raise in get_type
def has_type?
! @type.nil?
end
def get_type()
raise "No type #{self.object_id.to_s(16)}:#{self.class} " unless has_type?
@type
end
# return the metaclass
def meta
MetaClass.new self
end
def get_instance_variables
@type.names
end
def get_instance_variable( name )
index = instance_variable_defined(name)
#puts "getting #{name} at #{index}"
return nil if index == nil
return get_internal_word(index)
end
def set_instance_variable( name , value )
index = instance_variable_defined(name)
return nil if index == nil
return set_internal_word(index , value)
end
def instance_variable_defined( name )
@type.variable_index(name)
end
def padded_length
Padding.padded_words( @type.instance_length )
end
# parfait versions are deliberately called different, so we "relay"
# have to put the "@" on the names for sof to take them off again
def instance_variables
get_instance_variables.to_a.collect{ |n| "@#{n}".to_sym }
end
# name comes in as a ruby @var name
def instance_variable_ged name
var = get_instance_variable name.to_s[1 .. -1].to_sym
#puts "getting #{name} #{var}"
var
end
end
end