RosettaCodeData/Task/Factorial/AppleScript/factorial-3.applescript

64 lines
1.3 KiB
AppleScript

-- FACTORIAL -----------------------------------------------------------------
-- factorial :: Int -> Int
on factorial(x)
script product
on |λ|(a, b)
a * b
end |λ|
end script
foldl(product, 1, enumFromTo(1, x))
end factorial
-- TEST ----------------------------------------------------------------------
on run
factorial(11)
--> 39916800
end run
-- GENERIC FUNCTIONS ---------------------------------------------------------
-- enumFromTo :: Int -> Int -> [Int]
on enumFromTo(m, n)
if m > n 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 enumFromTo
-- 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 |λ|(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 |λ| : f
end script
end if
end mReturn