#!/bin/sh
#\
exec tclsh "$0" "$@"

package require TclOO
namespace import oo::*


# Account class from http://wiki.tcl.tk/20200 plus a little method to return current values

class create Account {
   constructor {{ownerName undisclosed}} {
       my variable total overdrawLimit owner
       set total 0
       set overdrawLimit 10
       set owner $ownerName
   }
   method deposit amount {
       my variable total
       set total [expr {$total + $amount}]
   }
   method withdraw amount {
       my variable {*}[info object vars [self]] ;# "auto-import" all variables
       if {($amount - $total) > $overdrawLimit} {
           error "Can't overdraw - total: $total, limit: $overdrawLimit"
       }
       set total [expr {$total - $amount}]
   }
   method transfer {amount targetAccount} {
       my variable total
       my withdraw $amount
       $targetAccount deposit $amount
       set total
   }
   method getInfo {} {
       my variable {*}[info object vars [self]] ;# "auto-import" all variables
       return "account of '$owner' has a total of $total."
   }
   destructor {
       my variable total
       if {$total} {puts "remaining $total will be given to charity"}
   }
} ;# class Account


proc destroyObject {objname args} {
  puts "destroyObject $objname, calling destructor"
  $objname destroy
}

# This procedure creates an object and saves its name in the variable a.
# That variable goes out of scope at the end of the procecure (Tcl has proc
# scope, not block scope - similar to JavaScript).
# The trace calls destroyObject when a goes out of scope.
proc p {} {
  set a [Account new "John Doe"]
  trace add variable a unset [list destroyObject $a]
  puts "** created object named '$a' **"
  puts "depositing 200"
  $a deposit 200
  puts [$a getInfo]
  try {
    puts "withdrawing 60"
    $a withdraw 60
  } on error e {
    puts stderr $e
  }
  puts [$a getInfo]
} ;# proc

p

puts "back in main (from proc p) and end of script."