Java annotation processing to KSP reference

Program elements

Java	Closest facility in KSP	Notes
AnnotationMirror	KSAnnotation
AnnotationValue	KSValueArguments
Element	KSDeclaration / KSDeclarationContainer
ExecutableElement	KSFunctionDeclaration
PackageElement	KSFile	KSP doesn't model packages as program elements.
Parameterizable	KSDeclaration
QualifiedNameable	KSDeclaration
TypeElement	KSClassDeclaration
TypeParameterElement	KSTypeParameter
VariableElement	KSValueParameter / KSPropertyDeclaration

Types

Because KSP requires explicit type resolution, some functionalities in Java can only be carried out by KSType and the corresponding elements before resolution.

Java	Closest facility in KSP	Notes
ArrayType	KSBuiltIns.arrayType
DeclaredType	KSType / KSClassifierReference
ErrorType	KSType.isError
ExecutableType	KSType / KSCallableReference
IntersectionType	KSType / KSTypeParameter
NoType	KSType.isError	N/A in KSP
NullType		N/A in KSP
PrimitiveType	KSBuiltIns	Not exactly same as primitive type in Java
ReferenceType	KSTypeReference
TypeMirror	KSType
TypeVariable	KSTypeParameter
UnionType	N / A	Kotlin has only one type per catch block. UnionType is also not observable by even Java annotation processors.
WildcardType	KSType / KSTypeArgument

Misc

Java	Closest facility in KSP	notes
Name	KSName
ElementKind	ClassKind / FunctionKind
Modifier	Modifier
NestingKind	ClassKind / FunctionKind
AnnotationValueVisitor
ElementVisitor	KSVisitor
AnnotatedConstruct	KSAnnotated
TypeVisitor
TypeKind	KSBuiltIns	Some can be found in builtins, otherwise check KSClassDeclaration for DeclaredType
ElementFilter	Collection.filterIsInstance
ElementKindVisitor	KSVisitor
ElementScanner	KSTopDownVisitor
SimpleAnnotationValueVisitor		No needed in KSP
SimpleElementVisitor	KSVisitor
SimpleTypeVisitor
TypeKindVisitor
Types	Resolver / utils	Some of the utils are also integrated into symbol interfaces
Elements	Resolver / utils

Details

How functionalities of Java annotation processing API can be carried out by KSP.

AnnotationMirror

Java	KSP equivalent
getAnnotationType	ksAnnotation.annotationType
getElementValues	ksAnnotation.arguments

AnnotationValue

Java	KSP equivalent
getValue	ksValueArgument.value

Element

Java	KSP equivalent
asType	ksClassDeclaration.asType(...) // Only available for KSClassDeclaration. Type arguments need to be supplied.
getAnnotation	// To be implemented.
getAnnotationMirrors	ksDeclaration.annotations
getEnclosedElements	ksDeclarationContainer.declarations
getEnclosingElements	ksDeclaration.parentDeclaration
getKind	type check & cast following ClassKind or FunctionKind
getModifiers	ksDeclaration.modifiers
getSimpleName	ksDeclaration.simpleName

ExecutableElement

Java	KSP equivalent
getDefaultValue	// To be implemented.
getParameters	ksFunctionDeclaration.parameters
getReceiverType	ksFunctionDeclaration.parentDeclaration
getReturnType	ksFunctionDeclaration.returnType
getSimpleName	ksFunctionDeclaration.simpleName
getThrownTypes	// Not needed in Kotlin.
getTypeParameters	ksFunctionDeclaration.typeParameters
isDefault	// Check whether parent declaration is an interface or not.
isVarArgs	ksFunctionDeclaration.parameters.any { it.isVarArg }

Parameterizable

Java	KSP equivalent
getTypeParameters	ksFunctionDeclaration.typeParameters

QualifiedNameable

Java	KSP equivalent
getQualifiedName	ksDeclaration.qualifiedName

TypeElement

Java	KSP equivalent
getEnclosedElements	ksClassDeclaration.declarations
getEnclosingElement	ksClassDeclaration.parentDeclaration
getInterfaces	ksClassDeclaration.superTypes.map { it.resolve() }.filter {(it?.declaration as? KSClassDeclaration)?.classKind == ClassKind.INTERFACE} // Should be able to do without resolution.
getNestingKind	// check KSClassDeclaration.parentDeclaration and inner modifier.
getQualifiedName	ksClassDeclaration.qualifiedName
getSimpleName	ksClassDeclaration.simpleName
getSuperclass	ksClassDeclaration.superTypes.map { it.resolve() }.filter { (it?.declaration as? KSClassDeclaration)?.classKind == ClassKind.CLASS } // Should be able to do without resolution.
getTypeParameters	ksClassDeclaration.typeParameters

TypeParameterElement

Java	KSP equivalent
getBounds	ksTypeParameter.bounds
getEnclosingElement	ksTypeParameter.parentDeclaration
getGenericElement	ksTypeParameter.parentDeclaration

VariableElement

Java	KSP equivalent
getConstantValue	// To be implemented.
getEnclosingElement	ksValueParameter.parentDeclaration
getSimpleName	ksValueParameter.simpleName

ArrayType

Java	KSP equivalent
getComponentType	ksType.arguments.first()

DeclaredType

Java	KSP equivalent
asElement	ksType.declaration
getEnclosingType	ksType.declaration.parentDeclaration
getTypeArguments	ksType.arguments

ExecutableType

Note: A KSType for a function is just a signature represented by the FunctionN<R, T1, T2, ..., TN> family.

Java	KSP equivalent
getParameterTypes	ksType.declaration.typeParameters, ksFunctionDeclaration.parameters.map { it.type }
getReceiverType	ksFunctionDeclaration.parentDeclaration.asType(...)
getReturnType	ksType.declaration.typeParameters.last()
getThrownTypes	// Not needed in Kotlin.
getTypeVariables	ksFunctionDeclaration.typeParameters

IntersectionType

Java	KSP equivalent
getBounds	ksTypeParameter.bounds

TypeMirror

Java	KSP equivalent
getKind	// Compare with types in KSBuiltIns for primitive types, Unit type, otherwise declared types

TypeVariable

Java	KSP equivalent
asElement	ksType.declaration
getLowerBound	// To be decided. Only needed if capture is provided and explicit bound checking is needed.
getUpperBound	ksTypeParameter.bounds

WildcardType

Java	KSP equivalent
getExtendsBound	if (ksTypeArgument.variance == Variance.COVARIANT) { ksTypeArgument.type } else { null }
getSuperBound	if (ksTypeArgument.variance == Variance.CONTRAVARIANT) { ksTypeArgument.type } else { null }

Elements

Java	KSP equivalent
getAllAnnotationMirrors	KSDeclarations.annotations
getAllMembers	getAllFunctions and getAllProperties, the latter is not there yet
getBinaryName	// To be decided, see Java Spec
getConstantExpression	we have constant value, not expression
getDocComment	// To be implemented
getElementValuesWithDefaults	// To be implemented.
getName	resolver.getKSNameFromString
getPackageElement	Package not supported, while package information can be retrieved, operation on package is not possible for KSP
getPackageOf	Package not supported
getTypeElement	Resolver.getClassDeclarationByName
hides	// To be implemented
isDeprecated	KsDeclaration.annotations.any { it.annotationType.resolve()!!.declaration.quailifiedName!!.asString() == Deprecated::class.quailifiedName }
overrides	KSFunctionDeclaration/KSPropertyDeclaration.overrides // member function of respective class
printElements	// KSP implemented basic toString() on most classes.

Types

Java	KSP equivalent
asElement	ksType.declaration
asMemberOf	resolver.asMemberOf
boxedClass	// Not needed
capture	// To be decided.
contains	KSType.isAssignableFrom
directSuperTypes	(ksType.declaration as KSClassDeclaration).superTypes
erasure	ksType.starProjection()
getArrayType	ksBuiltIns.arrayType.replace(...)
getDeclaredType	ksClassDeclaration.asType
getNoType	ksBuiltIns.nothingType / null
getNullType	// depends on the context, KSType.markNullable maybe useful.
getPrimitiveType	// Not needed, check for KSBuiltins
getWildcardType	// Use Variance in places expecting KSTypeArgument
isAssignable	ksType.isAssignableFrom
isSameType	ksType.equals
isSubsignature	functionTypeA == functionTypeB
isSubtype	ksType.isAssignableFrom
unboxedType	// Not needed.