Here is a full version without dependence on local library paths and the use of run script etc:
use AppleScript version "2.4"
use framework "Foundation"
use scripting additions
on run
set fp to "~/Desktop/"
script isRegular
on |λ|(x)
set lrStatus to fileStatus(filePath(fp & x))
if |Left| of lrStatus is missing value then
if "." is not first character of x and ¬
"NSFileTypeRegular" = NSFileType of |Right| of lrStatus then
{x}
else
{}
end if
else
{}
end if
end |λ|
end script
length of concatMap(isRegular, getDirectoryContents(fp))
end run
-- PASTED GENERICS ----------------------------------------------------
-- Left :: a -> Either a b
on |Left|(x)
{type:"Either", |Left|:x, |Right|:missing value}
end |Left|
-- Right :: b -> Either a b
on |Right|(x)
{type:"Either", |Left|:missing value, |Right|:x}
end |Right|
-- concatMap :: (a -> [b]) -> [a] -> [b]
on concatMap(f, xs)
tell mReturn(f)
set lng to length of xs
set acc to {}
repeat with i from 1 to lng
set acc to acc & |λ|(item i of xs, i, xs)
end repeat
end tell
return acc
end concatMap
-- filePath :: String -> FilePath
on filePath(s)
((current application's ¬
NSString's stringWithString:s)'s ¬
stringByStandardizingPath()) as string
end filePath
-- fileStatus :: FilePath -> Either String Dict
on fileStatus(fp)
set e to reference
set {v, e} to current application's NSFileManager's defaultManager's ¬
attributesOfItemAtPath:fp |error|:e
if v is not missing value then
|Right|(v as record)
else
|Left|((localizedDescription of e) as string)
end if
end fileStatus
-- getDirectoryContents :: FilePath -> IO [FilePath]
on getDirectoryContents(strPath)
set ca to current application
(ca's NSFileManager's defaultManager()'s ¬
contentsOfDirectoryAtPath:(stringByStandardizingPath of ¬
(ca's NSString's stringWithString:(strPath))) ¬
|error|:(missing value)) as list
end getDirectoryContents
-- Lift 2nd class handler function into 1st class script wrapper
-- mReturn :: First-class m => (a -> b) -> m (a -> b)
on mReturn(f)
if class of f is script then
f
else
script
property |λ| : f
end script
end if
end mReturn
