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ruby--ruby/lib/delegate.rb
matz f1fdbf080e * parse.y (str_extend): should check nesting parentheses in #{}.
* process.c (pst_wstopsig): returns nil unless WIFSTOPPED() is
  non-zero.

* process.c (pst_wtermsig): returns nil unless WIFSIGNALED() is
  non-zero.

* process.c (pst_wexitstatus): returns nil unless WIFEXITED() is
  non-zero.

* eval.c (rb_thread_select): tv_sec and tv_usec should not be
  negative.

* signal.c (posix_signal): do not set SA_RESTART for SIGVTALRM.

* parse.y (call_args2): block_arg may follow the first argument in
  call_args2.

* eval.c (stack_check): should avoid stack length check during
  raising SystemStackError exception.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@1852 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2001-11-21 15:42:12 +00:00

128 lines
2.6 KiB
Ruby

# Delegation class that delegates even methods defined in super class,
# which can not be covered with normal method_missing hack.
#
# Delegator is the abstract delegation class. Need to redefine
# `__getobj__' method in the subclass. SimpleDelegator is the
# concrete subclass for simple delegation.
#
# Usage:
# foo = Object.new
# foo2 = SimpleDelegator.new(foo)
# foo.hash == foo2.hash # => false
#
# Foo = DelegateClass(Array)
#
# class ExtArray<DelegateClass(Array)
# ...
# end
class Delegator
def initialize(obj)
preserved = ::Kernel.instance_methods
preserved -= ["to_s","to_a","inspect","==","=~","==="]
for t in self.type.ancestors
preserved |= t.instance_methods
preserved |= t.private_instance_methods
preserved |= t.protected_instance_methods
break if t == Delegator
end
for method in obj.methods
next if preserved.include? method
begin
eval <<-EOS
def self.#{method}(*args, &block)
begin
__getobj__.__send__(:#{method}, *args, &block)
rescue Exception
$@.delete_if{|s| /:in `__getobj__'$/ =~ s} #`
$@.delete_if{|s| /^\\(eval\\):/ =~ s}
raise
end
end
EOS
rescue SyntaxError
raise NameError, "invalid identifier %s" % method, caller(4)
end
end
end
def __getobj__
raise NotImplementError, "need to define `__getobj__'"
end
end
class SimpleDelegator<Delegator
def initialize(obj)
super
@obj = obj
end
def __getobj__
@obj
end
def __setobj__(obj)
@obj = obj
end
end
# backward compatibility ^_^;;;
Delegater = Delegator
SimpleDelegater = SimpleDelegator
#
def DelegateClass(superclass)
klass = Class.new
methods = superclass.instance_methods(true)
methods -= ::Kernel.instance_methods
methods |= ["to_s","to_a","inspect","==","=~","==="]
klass.module_eval <<-EOS
def initialize(obj)
@obj = obj
end
EOS
for method in methods
begin
klass.module_eval <<-EOS
def #{method}(*args, &block)
begin
@obj.__send__(:#{method}, *args, &block)
rescue
$@[0,2] = nil
raise
end
end
EOS
rescue SyntaxError
raise NameError, "invalid identifier %s" % method, caller(3)
end
end
return klass;
end
if __FILE__ == $0
class ExtArray<DelegateClass(Array)
def initialize()
super([])
end
end
ary = ExtArray.new
p ary.type
ary.push 25
p ary
foo = Object.new
def foo.test
25
end
def foo.error
raise 'this is OK'
end
foo2 = SimpleDelegator.new(foo)
p foo.test == foo2.test # => true
foo2.error # raise error!
end