When you wrap up a load of C/C++ code and use it as a Tcl shared
object extension, you often find yourself coding large, ungainly
*TclC* procedures which make much use of pointers.  I found it
useful to write a '''defaultDestructor''' procedure to do a final
cleanup of pointers created in procedure context:


 proc defaultDestructor { { level 1 } } {
     
      set msg "defaultDestructor:"
     
      set vnames [ uplevel $level info vars ]
     
      foreach vname $vnames {
        
         ;## dereference
         set vname [ uplevel $level set $vname ]
        
         if { [ llength $vname ] > 1 } { continue }
        
         switch -regexp -- $vname {
            {^_[0-9a-f]+_Frame_p$} {
                 set seqpt "destructFrame($vname):"
                 if { [ catch {
                    uplevel $level destructFrame $vname 
                    } err ] } {
                    lappend msg "$seqpt $err"
                    }
                               }
            {^_[0-9a-f]+_Element_p$} {
                 set seqpt "destructElement($vname):"
                 if { [ catch {
                    uplevel $level destructElement $vname 
                    } err ] } {
                    lappend msg "$seqpt $err" 
                    }
.

. more of the same elided...

.
            {^_[0-9a-f]+_FrameFile_p$} {
                set seqpt "closeFrameFile($vname):"
                if { [ catch {
                   uplevel $level closeFrameFile $vname 
                   } err ] } {
                   lappend msg "$seqpt $err" 
                   }
.

. even more elided!

. 
                } ;## end of switch
           } ;## end of foreach
    if { [ llength $msg ] > 1 } {
       return -code error $msg
       }
 }

----
If it is not too much to ask, could you please supply a bit more context on what the purpose of this code fragment is?  Sure, I can see what it is doing ''per se'', but I have no feeling for why it should be doing this.
I happen to believe the ''why'' of things is extremely important, since it is what determines the 
''what'' of things...
'''DKF'''