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bkirwi / decline

A composable command-line parser for Scala.
http://monovore.com/decline/
Apache License 2.0
647 stars 71 forks source link

Add an option to ignored undeclared options #505

Open goldmar opened 1 year ago

goldmar commented 1 year ago

Right now decline errors with Unexpected option whenever it is called with options that are not explicitly declared. There are cases when command-line options are used by libraries like Spark and I don't want to explicitly declare them in my application. Can we add a flag to Command.parse which would allow us to ignore undeclared options rather than error on them?

bkirwi commented 1 year ago

Could you say a little more your app is set up? How is the same argument list getting passed to both Decline and Spark?

(Often the right answer in these situations is to use a '--' to separate out two distinct lists of arguments... but I'd need to know more about your situation to be sure.)

On Tue, Nov 7, 2023 at 16:05 Mark @.***> wrote:

Right now decline errors with Unexpected option whenever it is called with options that are not explicitly declared. There are cases when command-line options are using by libraries (like Spark) and I don't want to explicitly declare them in my application. Can we add a flag to Command.parse which would allow us to ignore undeclared options rather than error on them?

— Reply to this email directly, view it on GitHub https://github.com/bkirwi/decline/issues/505, or unsubscribe https://github.com/notifications/unsubscribe-auth/AAMFXM5ETFNHKMRHRTL5KH3YDKOPTAVCNFSM6AAAAAA7B2KALCVHI2DSMVQWIX3LMV43ASLTON2WKOZRHE4DEMRRHE2DMNA . You are receiving this because you are subscribed to this thread.Message ID: @.***>

bkirwi commented 1 year ago

Part of the complexity, FWIW, is that undeclared options are ambiguous... to parse '--foo bar' you need to know if '--foo' is an option or a flag, and for an unrecognized option you can't know which by definition!

On Tue, Nov 7, 2023 at 18:53 Ben Kirwin @.***> wrote:

Could you say a little more your app is set up? How is the same argument list getting passed to both Decline and Spark?

(Often the right answer in these situations is to use a '--' to separate out two distinct lists of arguments... but I'd need to know more about your situation to be sure.)

On Tue, Nov 7, 2023 at 16:05 Mark @.***> wrote:

Right now decline errors with Unexpected option whenever it is called with options that are not explicitly declared. There are cases when command-line options are using by libraries (like Spark) and I don't want to explicitly declare them in my application. Can we add a flag to Command.parse which would allow us to ignore undeclared options rather than error on them?

— Reply to this email directly, view it on GitHub https://github.com/bkirwi/decline/issues/505, or unsubscribe https://github.com/notifications/unsubscribe-auth/AAMFXM5ETFNHKMRHRTL5KH3YDKOPTAVCNFSM6AAAAAA7B2KALCVHI2DSMVQWIX3LMV43ASLTON2WKOZRHE4DEMRRHE2DMNA . You are receiving this because you are subscribed to this thread.Message ID: @.***>

goldmar commented 1 year ago

I see, thank you! We are using AWS Glue to run our Spark jobs and pass the configuration through Glue jobs parameters but not all of it is used in the application itself. For instance, the AWS docs mention --conf and --user-jars-first.

On a high level, we are passing a lot of parameters through Glue which are shared across jobs and I would like to avoid changing this definition or defining these options in decline.

I took a look through decline's parsing code and this change does indeed not look trivial. At the same time, I saw that other libraries support this feature (see here for scopt). For now just looking to see if you think this is a feature that would be worth supporting.