RosettaCodeData/Task/Fibonacci-sequence/AppleScript/fibonacci-sequence-3.apples...

65 lines
1.1 KiB
AppleScript

-- fib :: Int -> Int
on fib(n)
-- (Int, Int) -> (Int, Int)
script lastTwo
on lambda([a, b])
[b, a + b]
end lambda
end script
item 1 of foldl(lastTwo, {0, 1}, range(1, n))
end fib
-- TEST
on run
fib(32)
--> 2178309
end run
-- GENERIC FUNCTIONS
-- foldl :: (a -> b -> a) -> a -> [b] -> a
on foldl(f, startValue, xs)
tell mReturn(f)
set v to startValue
set lng to length of xs
repeat with i from 1 to lng
set v to lambda(v, item i of xs, i, xs)
end repeat
return v
end tell
end foldl
-- Lift 2nd class handler function into 1st class script wrapper
-- mReturn :: Handler -> Script
on mReturn(f)
if class of f is script then
f
else
script
property lambda : f
end script
end if
end mReturn
-- range :: Int -> Int -> [Int]
on range(m, n)
if n < m then
set d to -1
else
set d to 1
end if
set lst to {}
repeat with i from m to n by d
set end of lst to i
end repeat
return lst
end range