#	IMAGE
#
#	Generalized image of Icon object
#
#	Ralph E. Griswold
#
#	Last modified 2/1/86
#

procedure Image(x,done)
   /done := table()
   if match("record ",image(x)) then return rimage(x,done)
   else return case type(x) of {
      "list":  limage(x,done)
      "table": timage(x,done)
      "set":   simage(x,done)
      default: image(x)
      }
end

#  list image
#
procedure limage(a,done)
   static i
   local s, tag
   initial i := 0
   if \done[a] then return done[a]
   done[a] := tag := "L" || (i +:= 1)
   if *a = 0 then s := tag || ":[]" else {
      s := tag || ":["
      every s ||:= Image(!a,done) || ","
      s[-1] := "]"
      }
   return s
end

#  record image
#
procedure rimage(x,done)
   static i
   local s, tag
   initial i := 0
   s := image(x)
					#  might be record constructor
   if match("record constructor ",s) then return s
   if \done[x] then return done[x]
   done[x] := tag := "R" || (i +:= 1)
   s ?:=  (="record " & (":" || (tab(upto('(') + 1))))
   if *x = 0 then s := tag || s || ")" else {
      s := tag || s
      every s ||:= Image(!x,done) || ","
      s[-1] := ")"
      }
   return s
end

# set image
#
procedure simage(S,done)
   static i
   local s, tag
   initial i := 0
   if \done[S] then return done[S]
   done[S] := tag := "S" || (i +:= 1)
   if *S = 0 then s := tag || ":[]" else {
      s := tag || ":["
      every s ||:= Image(!S,done) || ","
      s[-1] := "]"
      }
   return s
end

#  table image
#
procedure timage(t,done)
   static i
   local s, tag, a, a1
   initial i := 0
   if \done[t] then return done[t]
   done[t] := tag := "T" || (i +:= 1)
   if *t = 0 then s := tag || ":[]" else {
      a := sort(t,3)
      s := tag || ":["
      while s ||:= Image(get(a),done) || "->" || Image(get(a),done) || ","
      s[-1] := "]"
      }
   return s
end