Morfly

interface KSVisitor<D, R> {
    fun visitNode(node: KSNode, data: D): R

    fun visitClassDeclaration(classDeclaration: KSClassDeclaration, data: D): R
    
    fun visitPropertyDeclaration(property: KSPropertyDeclaration, data: D): R

    // ~20 more functions
}

Morfly

class FunctionProcessor(...) : SymbolProcessor {
    ...

    inner class Visitor(private val file: OutputStream) : KSVisitorVoid() {
        
        override fun visitClassDeclaration(classDeclaration: KSClassDeclaration, data: Unit) {
        }
        
        override fun visitPropertyDeclaration(property: KSPropertyDeclaration, data: Unit) {
        }

Morfly

package com.morfly

@Function(name = "myAmazingFunction")
interface MyAmazingFunction

fun main() {
    println("Hello World!")
}

Morfly

interface KSNode {
    ...
    
    fun <D, R> accept(visitor: KSVisitor<D, R>, data: D): R
}

Morfly

class KSPropertyDeclarationImpl(...) : KSPropertyDeclaration, ... {
    ...
    
    override fun <D, R> accept(visitor: KSVisitor<D, R>, data: D): R {
        return visitor.visitPropertyDeclaration(this, data)
    }
}

Morfly

...

kotlin {
    sourceSets {
        main {
            kotlin.srcDirs(file("$buildDir/generated/ksp/main/kotlin"))
        }
    }
}

Morfly

override fun visitClassDeclaration(classDeclaration: KSClassDeclaration, data: Unit) {
    if (classDeclaration.classKind != ClassKind.INTERFACE) {
        logger.error("Only interface can be annotated with @Function", classDeclaration)
        return
    }

    // Getting the @Function annotation object.
    val annotation: KSAnnotation = classDeclaration.annotations.first {
        it.shortName.asString() == "Function"
    }

Morfly

override fun visitClassDeclaration(classDeclaration: KSClassDeclaration, data: Unit) {
    ...
    
    // Getting the list of member properties of the annotated interface.
    val properties: Sequence<KSPropertyDeclaration> = classDeclaration.getAllProperties()
        .filter { it.validate() }

    // Generating function signature.
    file += "\n"
    if (properties.iterator().hasNext()) {

Morfly

override fun visitPropertyDeclaration(property: KSPropertyDeclaration, data: Unit) {
    // Generating argument name.
    val argumentName = property.simpleName.asString()
    file += "    $argumentName: "

    // Generating argument type.
    val resolvedType: KSType = property.type.resolve()
    file += resolvedType.declaration.qualifiedName?.asString() ?: run {
        logger.error("Invalid property type", property)
        return

Morfly

fun visitPropertyDeclaration(...) { ... }

private fun visitTypeArguments(typeArguments: List<KSTypeArgument>) {
    if (typeArguments.isNotEmpty()) {
        file += "<"
        typeArguments.forEachIndexed { i, arg ->
            visitTypeArgument(arg, data = Unit)
            if (i < typeArguments.lastIndex) file += ", "
        }
        file += ">"