Is there a slick kotlin way of handling this I have a series

Question

Is there a slick kotlin way of handling this I have a series of cmdline args like root home foo root other dir algo MD5 and I want to turn them into a Map lt String List lt String gt gt

tulio · Answer

chb0kotlin Have you considered using some lib to handle CLI params

damian · Answer

If so I d definitely recommend JCommander simple smile <http jcommander org kotlin>

chb0kotlin · Answer

I am intentionally not using any libraries normally I would but this is for demonstrating kotlins capabilities as a language I need to take the commandline args and turn it into necessary types to pass to a contructor ``` public DeDup Set lt File gt roots String hashAlgo Set lt String gt fileTypes this roots = roots this hashAlgo = hashAlgo this fileTypes = fileTypes ```

xenomachina · Answer

There are lots of corner cases to parsing command line args eg what happens if number of arguments is odd

xenomachina · Answer

shameless plug kotlin argparser would make parsing those options pretty easy ``` class Args parser ArgParser val root by parser adding directories to search val algo by parser storing hash algorithm val fileTypes by parser adding file types to process initialValue = mutableSetOf lt String gt this ```

cedric · Answer

< chb0kotlin> I respect your decision not to use any library but if you have any JCommander question ask away I m using it with Kotlin without any efforts although it s obviously not an idiomatically Kotlin library

tulio · Answer

< chb0kotlin> here a snippet to start with just the happy path

tulio · Answer

val keys values = args partition it startsWith val result = keys zip values groupBy it first map it key to it value map it second toMap

tulio · Answer

Assuming that args is a Array lt String gt

chb0kotlin · Answer

I never thought to use partition I am gonna have to give this a try

tulio · Answer

< chb0kotlin> I thought in a much more elegant solution

tulio · Answer

args partition it startsWith let it first zip it second groupBy it first it second

chb0kotlin · Answer

WOW

cedric · Answer

Note that this will obviously fail if the command you re parsing is not using an exact even number of args

tulio · Answer

Exactly As I said this cover only the happy path

chb0kotlin · Answer

That s all ok It s for demonstrating how Kotlin can save lines of code and provide clarity The application it s replicating doesn t handle commandline args any better

chb0kotlin · Answer

Def appreciate it If I can get team buy in for kotlin on the next project I will revisit this slightly smiling face