RosettaCodeData/Task/Sierpinski-triangle/AppleScript/sierpinski-triangle-1.apple...

104 lines
2.4 KiB
AppleScript

-- SIERPINKSI TRIANGLE -------------------------------------------------------
-- sierpinski :: Int -> [String]
on sierpinski(n)
if n > 0 then
set previous to sierpinski(n - 1)
set padding to replicate(2 ^ (n - 1), space)
script alignedCentre
on |λ|(s)
concat(padding & s & padding)
end |λ|
end script
script adjacentDuplicates
on |λ|(s)
unwords(replicate(2, s))
end |λ|
end script
-- Previous triangle block centered,
-- and placed on 2 adjacent duplicates.
map(alignedCentre, previous) & map(adjacentDuplicates, previous)
else
{"*"}
end if
end sierpinski
-- TEST ----------------------------------------------------------------------
on run
unlines(sierpinski(4))
end run
-- GENERIC FUNCTIONS ---------------------------------------------------------
-- concat :: [[a]] -> [a] | [String] -> String
on concat(xs)
if length of xs > 0 and class of (item 1 of xs) is string then
set acc to ""
else
set acc to {}
end if
repeat with i from 1 to length of xs
set acc to acc & item i of xs
end repeat
acc
end concat
-- intercalate :: Text -> [Text] -> Text
on intercalate(strText, lstText)
set {dlm, my text item delimiters} to {my text item delimiters, strText}
set strJoined to lstText as text
set my text item delimiters to dlm
return strJoined
end intercalate
-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
tell mReturn(f)
set lng to length of xs
set lst to {}
repeat with i from 1 to lng
set end of lst to |λ|(item i of xs, i, xs)
end repeat
return lst
end tell
end map
-- 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
-- replicate :: Int -> a -> [a]
on replicate(n, a)
set out to {}
if n < 1 then return out
set dbl to {a}
repeat while (n > 1)
if (n mod 2) > 0 then set out to out & dbl
set n to (n div 2)
set dbl to (dbl & dbl)
end repeat
return out & dbl
end replicate
-- unlines, unwords :: [String] -> String
on unlines(xs)
intercalate(linefeed, xs)
end unlines
on unwords(xs)
intercalate(space, xs)
end unwords