Is it possible to leverage ksp to generate non kotlin code I

Question

Is it possible to leverage ksp to generate non kotlin code I d like to leverage the symbol processing to generate swift files

Big Chungus · Answer

Can t see why not Just write them via jvm File api

Paul Woitaschek · Answer

But that breaks incremental things right How would I know which files to delete and which ones to keep

Big Chungus · Answer

Oh you mean you want to fully replace some kotlin files with swift

Paul Woitaschek · Answer

No of cause not stuck out tongue But right now when I generate a file based on a kotlin file and compile the generated file gets created When I now delete the originating file and compile the generated file will also be deleted But that step wouldn t happen when I just use the file api so dead generated files will be left I guess

Big Chungus · Answer

Just write a file to different dir not controlled by ksp You can pass on the path via ksp gradle options

Paul Woitaschek · Answer

But how would I know when to delete the file

Big Chungus · Answer

It won t That s for you to manage either manually or with a gradle task

Paul Woitaschek · Answer

But how could I possibly know that

Big Chungus · Answer

Keep your own cache during generation maybe Could be as simple as storing a json map of kt sources ang generated swift files Then at the end of each ksp task compare the new such map with previous one and clean up

Big Chungus · Answer

In short generate map during ksp compare new map with cached one in your custom gradle task or doLast block in ksp task cleanip and move new map to cache

Paul Woitaschek · Answer

But what would be in that map

Paul Woitaschek · Answer

On incremental rounds the ksp allFiles will only contain the changed ones

Big Chungus · Answer

``` path to source kt path to geterated swift ```

elect · Answer

I used KSP the other day to generate plain java sources The previous implementation was using Apache Velocity Kotlin proved extremely nice

Grégory Lureau · Answer

Why not just using CodeGenerator createNewFile Dependencies false false listOf source kt extensionName = swift

Paul Woitaschek · Answer

Because that would put it in the kotlin sourceset

Grégory Lureau · Answer

Mmmh from memory it goes into a resource directory

Grégory Lureau · Answer

Not finding the documentation right now but an extension kt goes into kotlin java into java and anything else I suppose will go into resources

Grégory Lureau · Answer

Here s an example of associating not kotlin files to one or multiple class declaration <https github com google ksp blob a38ac896fa80a659907485c02bfa688b7d79ca25 integration tests src test resources incremental classpath validator src main kotlin Validator kt L63|https github com google ksp blob a38ac896fa80a659907485c02bfa688b7d79ca25 integr es incremental classpath validator src main kotlin Validator kt>

Paul Woitaschek · Answer

Uh that might work

Paul Woitaschek · Answer

It half works It creates the files but then ksp crashes with ``` gt Task lifecycle kspKotlinMetadata FAILED e Source file or directory not found home paul repos yazio shared lifecycle build generated ksp commonMain kotlin``` This is happening when only swift files are generated but no kotlin files for the module

elect · Answer

open an issue they are usually quite prompt to reply

Paul Woitaschek · Answer

Will do slightly smiling face

elect · Answer

anyway cool experiments Paul keep us updated

glureau · Answer

Is it because the kotlin directory is removed not normal but known bug AFAIK and you still have an explicit reference in your build gradle on this directory

Paul Woitaschek · Answer

But what removes it

Grégory Lureau · Answer

I was thinking about this feedback I experienced the same behaviour myself <https kotlinlang slack com archives C013BA8EQSE p1635931295085600>

Paul Woitaschek · Answer

< elect> gt anyway cool experiments Paul keep us updated Keeping you updated wink

Grégory Lureau · Answer

Thanks Do you plan to open source your tool I m working on similar stuff from JS myself and could be interested by this one too

Paul Woitaschek · Answer

I don t believe that it would work on a one library fits all level It has many things specific to our language and also some exceptions for non generated code integration Also this only works because all our data structures are immutable If you would generate structs from mutable structures that would probably lead to unexpected behavior

Grégory Lureau · Answer

Exactly the same problem for JS that s why I m providing wrapper by defaults so those forward everything binding 2 ways changing types in the middle