# Listing of doc/example-scripts/rosetta-classes.tcl

## Rosetta Example: Classes

For details see http://rosettacode.org/wiki/Classes

    package req nx

    nx::Class create summation {
      :method init {} {set :v 0}
      :public method add {x} {incr :v $x}
      :public method value {} {return ${:v}}
      :public method destroy {} {puts "ended with value [:value]"; next}
    }

### Demonstrating the behavior in a shell:

    % set sum [summation new]
    % $sum value
    0
    % $sum add 1
    1
    % $sum add 2
    3
    % $sum add 3
    6
    % $sum add 4
    10
    % $sum value
    10

During the destroy of the object, `ended with value 10` is printed

    % $sum destroy