Cats effect Decline example

Composable command-line parsing for Scala

https://ben.kirw.in/decline/

Using in an effectful manner

Just run the below examples, replacing com.felstar.HelloWorld with com.felstar.HelloWorldIO

To run

Run it with no params

sbt "runMain com.felstar.HelloWorld" 

Run it with --help param, displays the help for the app and its params

sbt "runMain com.felstar.HelloWorld --help" 

Run it with --target param

sbt "runMain com.felstar.HelloWorld --target Dino" 

Run it with -t short param

sbt "runMain com.felstar.HelloWorld -t Ralf" 

Run it with positional params

sbt "runMain com.felstar.HelloWorld Dave Ralf" 

Run it with forbidden name for positional param

sbt "runMain com.felstar.HelloWorld John" 

Run it with refined number that doesn't match PosInt

sbt "runMain com.felstar.HelloWorld --posInt -123" 

Run it with unparseable number

sbt "runMain com.felstar.HelloWorld --posInt woof"