(* Modified for Moscow ML from SML/NJ Library 0.2 file dynamic-array.sml * * COPYRIGHT (c) 1993 by AT&T Bell Laboratories.   * See file mosml/copyrght/copyrght.att for details. * * Arrays of unbounded length * *) datatype 'elem array = BLOCK of 'elem Array.array ref * 'elem fun array (sz, dflt) = BLOCK(ref (Array.array (sz,dflt)),dflt) fun subArray (BLOCK(arr,dflt),lo,hi) = let      val arrval = !arr      fun copy i = (Array.sub(arrval,i+lo)) handle _ => dflt      in        BLOCK(ref(Array.tabulate(hi-lo,copy)),dflt)      end fun fromList (initlist, dflt) = BLOCK(ref (Array.fromList initlist),dflt) fun tabulate (sz,fillfn,dflt) = BLOCK(ref (Array.tabulate (sz,fillfn)),dflt) fun default (BLOCK(_,dflt)) = dflt fun sub (BLOCK(arr,dflt),idx) = (Array.sub(!arr,idx))       handle Subscript => if idx < 0 then raise Subscript else dflt fun bound (BLOCK(arr,_)) = Array.length (!arr) fun expand(arr,oldlen,newlen,dflt) = let      fun fillfn i = if i < oldlen then Array.sub(arr,i) else dflt      in        Array.tabulate(newlen,fillfn)      end fun update (b as BLOCK(arr,dflt),idx,v) = let       fun max(x, y: int) = if x>y then x else y      val len = bound b      in        if idx >= len           then arr := expand(!arr,len,max(len+len,idx+1),dflt)           else ();        Array.update(!arr,idx,v)      end