-- File:	TCollection_Sequence.cdl
-- Created:	Fri Sep 11 17:34:39 1992
-- Author:	Mireille MERCIEN
--		<mip@sdsun3>
---Copyright:	 Matra Datavision 1992


class BaseSequence from TCollection 

	---Purpose: Definition of a base class for all instanciations
	--          of sequence.
	--          
	--          The methods : Clear, Remove accepts a pointer to a
	--          function  to use  to delete the  nodes. This allow
	--          proper    call of  the  destructor  on  the Items.
	--          Without adding a  virtual function pointer to each
	--          node or each sequence.

raises
    
    NoSuchObject from Standard,
    OutOfRange from Standard

is 

	Create returns  BaseSequence is protected;
		---Purpose: Creation of an empty sequence.
		
	Create(Other : BaseSequence) returns BaseSequence from TCollection
		---Purpose: Creation by copy of existing Sequence.
		--  Warning: This constructor prints a warning message.
		-- We recommand to use the operator =.
	is private;
	
	IsEmpty(me) returns Boolean;
        	---Level: Public
		---Purpose: returns True if the sequence <me> contains no elements.
		---C++: inline
	
	Length(me)  returns Integer from Standard;
        	---Level: Public
		---Purpose: Returns  the  number  of element(s) in the
		-- sequence.  Returns zero if the sequence is empty.
		---C++: inline

	Clear(me : in out; DelNode : Address) is protected;
        	---Level: Private

	PAppend(me : in out; Node : Address)
	is protected;

	PAppend(me : in out; S : in out BaseSequence)
        	---Level: Public
		---Purpose: Concatenates <S> at the end of <me>. 
		-- <S> is cleared.
		--  Example:
		-- before
		--   me = (A B C)
		--   S  = (D E F)
		-- after
		--   me = (A B C D E F)
		--   S  = ()
	is protected;

	PPrepend(me : in out; Node : Address)
    	is protected;

	PPrepend(me : in out; S : in out BaseSequence)
        	---Level: Public
		---Purpose: Concatenates <S> at the beginning of <me>.
		-- <S> is cleared.
		--  Example:
		-- before 
		-- me = (A B C) S =  (D E F)
		-- after me = (D E F A B C) 
		-- S = ()
	is protected;

	Reverse(me : in out);
        	---Level: Public
		---Purpose: Reverses the order of items on <me>.
		--  Example:
		-- before
		--   me = (A B C)
		-- after
		--   me = (C B A)

	PInsertAfter(me : in out; Index : Integer from Standard; Node : Address ) 
	raises OutOfRange from Standard
        is protected;
	
	PInsertAfter(me : in out; Index : Integer from Standard; S : in out BaseSequence) 
	raises OutOfRange from Standard
        	---Level: Public
		---Purpose: Inserts the sequence <S> in <me> after the
		-- position <Index>. <S> is cleared.
		-- Raises an exception if the index is out of bound.
		--  Example:          
		-- before
		--   me = (A B C), Index = 3, S = (D E F)
		-- after
		--   me = (A B C D E F)
		--   S  = ()
	is protected;



	Exchange(me : in out; I, J : Integer from Standard) 
    	raises OutOfRange from Standard;
        	---Level: Public
		---Purpose: Swaps  elements  which    are  located  at
		-- positions <I> and <J> in <me>.
		-- Raises an exception if I or J is out of bound.
		--  Example:
		-- before
		--   me = (A B C), I = 1, J = 3            
		-- after
		--   me = (C B A)           

              
	PSplit(me : in out; Index : Integer from Standard; Sub : in out BaseSequence) 
        raises OutOfRange from Standard 
        	---Level: Public
		---Purpose: Keeps in <me> the items 1 to <Index>-1 and
		-- puts  in  <Sub> the  items <Index>  to the end.
		--  Example:
		-- before
		--   me = (A B C D) ,Index = 3
		-- after
		--   me  = (A B)
		--   Sub = (C D)
	is protected;

	Remove(me : in out; Index : Integer from Standard; DelNode : Address) 
    	raises OutOfRange from Standard
    	is protected;

	Remove(me : in out; FromIndex, ToIndex : Integer from Standard; DelNode : Address) 
      	raises OutOfRange from Standard
    	is protected;
	
	Find(me; Index : Integer from Standard) returns Address from Standard
            ---Level: Internal
	    ---Purpose: Returns the node at position <index>.
	is protected;

	Nullify(me : in out ) is private;
	    ---Level: Internal
            ---Purpose: Clear all fields.
            --          

fields 
  FirstItem 	: Address from Standard is protected;
  LastItem  	: Address from Standard is protected;
  CurrentItem   : Address from Standard is protected;
  CurrentIndex  : Integer from Standard is protected;
  Size 		: Integer from Standard is protected;    
end;