Regarding advance TCL scripts

Hi,

Objective : Want to get all the endpoints for a given startpoint with positive slack only.

I am bit new to ets :)

##--------------------------------- Generic Procedure defination -----------------------------------------

proc user_get_object_names {collection} {
   set objectList {}
   foreach_in_collection item $collection {
    lappend objectList [get_object_name $item]
   }
   return $objectList
}

proc user_print_object_names {collection} {
  set objectListPrint {}
  foreach_in_collection item $collection {
    set name [get_object_name $item]
    puts "Path : $name\n"
  }
  return $objectListPrint
}

##-------------------------------------------------------------------------------

set start_point aa/bb/some_D

set paths_list_fanout {}
set paths_fanout_list [user_get_object_names $paths_fanout]

set sz 0
set rpt_fanout 0
foreach currpath $paths_fanout_list {
    set rpt_curr_data [report_timing -collection -to $currpath]
    append_to_collection rpt_fanout $rpt_curr_data
}

set sz [sizeof_collection $rpt]
puts "Total fanout paths are $sz"

set szpos 0; set pos_fanout 0
set pos_fanout [filter_collection $rpt_fanout {(slack > 0.0)}]
set szpos [sizeof_collection $pos_fanout]
puts "Total fanout paths with positive slack are $szpos" ## This prints number of paths with positive slack

 user_print_object_names $pos_fanout  

I am expecting now after this proc call it should print all the path names with positive slack in collection $pos_fanout but its not happening.

Can anyone point out where I am going wrong please.

 Also can some one point me to a good starting source to understand collection better. 

Regards,
Abhi