RosettaCodeData/Task/Levenshtein-distance/AppleScript/levenshtein-distance-2.applescript
2023-07-01 13:44:08 -04:00

154 lines
3.4 KiB
AppleScript

-- levenshtein :: String -> String -> Int
on levenshtein(sa, sb)
set {s1, s2} to {characters of sa, characters of sb}
script
on |λ|(ns, c)
script minPath
on |λ|(z, c1xy)
set {c1, x, y} to c1xy
minimum({y + 1, z + 1, x + fromEnum(c1 is not c)})
end |λ|
end script
set {n, ns1} to {item 1 of ns, rest of ns}
scanl(minPath, n + 1, zip3(s1, ns, ns1))
end |λ|
end script
last item of foldl(result, enumFromTo(0, length of s1), s2)
end levenshtein
--------------------------- TEST ---------------------------
on run
script test
on |λ|(tuple)
set {sa, sb} to tuple
levenshtein(sa, sb)
end |λ|
end script
map(test, [["kitten", "sitting"], ["sitting", "kitten"], ¬
["rosettacode", "raisethysword"], ["raisethysword", "rosettacode"]])
--> {3, 3, 8, 8}
end run
-------------------- GENERIC FUNCTIONS ---------------------
-- enumFromTo :: Int -> Int -> [Int]
on enumFromTo(m, n)
if m n then
set lst to {}
repeat with i from m to n
set end of lst to i
end repeat
lst
else
{}
end if
end enumFromTo
-- fromEnum :: Enum a => a -> Int
on fromEnum(x)
set c to class of x
if c is boolean then
if x then
1
else
0
end if
else if c is text then
if x "" then
id of x
else
missing value
end if
else
x as integer
end if
end fromEnum
-- 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
-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
-- The list obtained by applying f
-- to each element of 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
-- minimum :: Ord a => [a] -> a
on minimum(xs)
set lng to length of xs
if lng < 1 then return missing value
set m to item 1 of xs
repeat with x in xs
set v to contents of x
if v < m then set m to v
end repeat
return m
end minimum
-- mReturn :: First-class m => (a -> b) -> m (a -> b)
on mReturn(f)
-- 2nd class handler function lifted into 1st class script wrapper.
if script is class of f then
f
else
script
property |λ| : f
end script
end if
end mReturn
-- scanl :: (b -> a -> b) -> b -> [a] -> [b]
on scanl(f, startValue, xs)
tell mReturn(f)
set v to startValue
set lng to length of xs
set lst to {startValue}
repeat with i from 1 to lng
set v to |λ|(v, item i of xs, i, xs)
set end of lst to v
end repeat
return lst
end tell
end scanl
-- zip3 :: [a] -> [b] -> [c] -> [(a, b, c)]
on zip3(xs, ys, zs)
script
on |λ|(x, i)
{x, item i of ys, item i of zs}
end |λ|
end script
map(result, items 1 thru ¬
minimum({length of xs, length of ys, length of zs}) of xs)
end zip3