generator_pattern.pai

# Using exceptions, you can easily create generator behavior.

#[[
@brief Create a new generator that lists the arguments passed to the generator one by one.
@return null
#]]
function generator.new
    let iter_list i = {@} 0
end

#[[
@brief Generate the next item in the list, if any.
@return any The next item in the list.
@error generator_end When there are no more items to pop off the list.
#]]
function generator.next
    let i += 1
    if {iter_list[i] = null} then
        error 'End of generator' as generator_end
    end
    return "<{iter_list[i]}>"
end

# Create a new generator
call generator.new A B C D E F

# Iterate over it until there are no more items.
until generator_end do
    print "Generated item: {\generator.next()}"
end

print "Execution finished."