Class ContextPtr

			
				
					
						
							
					
					
						
							   class  
							
								ContextPtr
							
							 : public ObjectPtr  
						
					
				
				
					
						 Programmer: Matt Splett  
					
				
			
			 
			
				Description: 
			
			
				 To facilitate accessing specific slots of a SmallTalk
 Context. Also to aid in the creation of them.
 
			
			   
			
				Public Methods: 
			
			
				
					  
					
					static ObjectPtr  
					
						create 
					
					( ObjectPtr & receiver, MethodPtr & meth, 					 ArrayPtr & args ); 
					

					  create a context from a given receiver, compiled method
 and array of arguments		                                           
 
					

					

					   
					

					ObjectPtr  
					
						blockCopy 
					
					( ); 
					

					  used to create a block context out of the active
 context.
 
					

					

					   
					

					static ContextPtr  
					
						convert 
					
					(ObjectPtr); 
					

					  veryify the class type of the object pointer before casting
 to a context pointer.
 
					

					

					   
					

					 
					
						ContextPtr 
					
					( const ObjectPtr &); 
					

					  Conversion constructor from base class
 
					

					

					   
					

					ObjectPtr &  
					
						receiver 
					
					(); 
					

					  slot 0 : Object   
 
					

					

					   
					

					MethodPtr &  
					
						method 
					
					(); 
					

					  slot 1 : Compiled Method
 
					

					

					   
					

					IntegerPtr &  
					
						ip 
					
					(); 
					

					  slot 3 : integer - Instruction Pointer
 
					

					

					   
					

					ObjectPtr &  
					
						tempFrame 
					
					( UInteger ); 
					

					  returns a reference to the indexed element
 of the tempFrame.
 
					

					

					   
					

					UInteger  
					
						tempFrameSize 
					
					( ); 
					

					  returns the number of elements in the tempFrame.
 
					

					

					   
					

					void  
					
						appendTempFrame 
					
					( ArrayPtr & ); 
					

					  Used to extend the tempFrame.
 
					

					

					   
					

					void  
					
						shrinkTempFrame 
					
					( ); 
					

					  Used when returning from a block to discard the
 insertion variables, a.k.a. frame extension.
 
					

					

					   
					

					Byte  
					
						opCode 
					
					(); 
					

					  current instruction or single byte argument.
 
					

					

					   
					

					BigByte  
					
						bigOpCode 
					
					(); 
					

					  current double byte argument.
 SIDE EFFECT: also calls advance() once!
 
					

					

					   
					

					Boolean  
					
						advance 
					
					( SInteger skip = 1L ); 
					

					  move ip forward one opcode.
 TESTING
 
					

					

					  
				
			
			  
			
				Protected Methods: 
			
			
				
					  
					
					 
					
						ContextPtr 
					
					( ); 
					

					  default constructor - never implemented.
 
					

					

					   
					

					ArrayPtr &  
					
						tempFrame 
					
					(); 
					

					  slot 2 : Array  
 Because tempFrame is a little twisted, this
 should only be used internally.
 tempFrame( UInteger ) for access into the frame,
 and tempFrameSize().
 
					

					

					   
					

					static ClassPtr &  
					
						klassPtr 
					
					(); 
					

					    
					

					

					  
				
			
			
				Protected Members:
	`class ContextPtr : public ObjectPtr`
	Programmer: Matt Splett