/utilagview.txt 
\ AgView--aggregate view of some underlying set of data structures   vandys
\ AgView is a generic class for holding a list of data structures, and
\  permitting the aggregate to be a polymorphic representation of the
\  member elements. XYZZY
only extensions definitions

Collection -> subclass: AgView ivars: intcell list endivars

AgView -> class -> :method new ( self -- agbt )   super-> new
   List -> new   over AgView>list ! method;
: ag>list ( agbt -- list )   AgView>list @ ;
AgView -> :method free ( self -- )
   dup ag>list -> free   super-> free method;

AgView -> :method agadd ( elem self -- )   ag>list -> add method;
AgView -> :method ! ( val key self -- )   ag>list -> last   -> ! method;
AgView -> :method add ( elem self -- )   ag>list -> last   -> add method;

: (.ag) ( 0 elem -- )   nip   -> . ; scrLocal
AgView -> :method .elems ( self -- )   0   ['] (.ag)
   rot ag>list -> do method;




\ AgView--aggregate view of some underlying set of data structures   vandys

variable (agCount) scrLocal
: (agSize) ( 0 bt -- )   nip   -> size   (agCount) +! ; scrLocal
AgView -> :method size ( self -- u )   (agCount) off   ag>list
   0   ['] (agSize)   rot -> do   (agCount) @ method;
AgView -> :method in? ( key self -- ? )   ag>list { key list }
   list -> size 0 ?do   i list @ { elem }   key elem -> in? if
      unloop   true exit then
   loop   false method;















\ AgView key manipulation                                            vandys

variable (agKey) scrLocal

: (agnextKey) ( key ag -- )   -> nextKey if   (agKey) @ ?dup if min then
   (agKey) !   then ; scrLocal
AgView -> :method nextKey ( key ag -- key' T | F )   ag>list
   (agKey) off   ['] (agnextKey)   swap -> do
   (agKey) @ ?dup 0<> method;

: (agtopKey) ( 0 bt -- )   nip
   -> topKey (agKey) @ max   (agKey) ! ; scrLocal
AgView -> :method topKey ( ag -- key )   ag>list
   (agKey) off   0   ['] (agtopKey)   rot -> do
   (agKey) @ method;