Dealing with large numbers

[Mark Wieder]

All-

I just ran into an integer overflow problem and I'm wondering if there
is a preferred way of dealing with this. I get the right number of
digits, but after iteration 79 the last digits are all zero. Is there
a way of dealing with large numbers? Here's a simple handler that
gives wrong answers:

--------------------------------------------------
-- Find the Nth Fibonacci number
-- Usage: Fibonacci(100)
-- note: this overflows at around iteration 79
--------------------------------------------------
on Fibonacci pIteration
    local tFibNum
    local tPrevious
    local tTemp
    
    -- prime the pump
    put 1 into tPrevious -- Fibonacci number 1
    put 1 into tFibNum -- Fibonacci number 2
    repeat with x=3 to pIteration
        put tFibNum into tTemp
        add tPrevious to tFibNum
        put tTemp into tPrevious
        -- show your work
        put "Iteration" && x & "=" && tFibNum & cr after field 1
    end repeat
end Fibonacci

-- 
-Mark Wieder
 mwieder at ahsoftware.net