Scala 2 vs Scala 3 macros

Scala 2

Scala 3

(c: scala.reflect.macros.blackbox.Context)

(using quotes: scala.quoted.Quotes)

c.WeakTypeTag[A] (or c.TypeTag[A])

scala.quoted.Type[A]

c.Type

quotes.reflect.TypeRepr

c.Expr[A]

scala.quoted.Expr[A]

c.universe.Tree

quotes.reflect.Tree

c.prefix

no counterpart

Scala 2

Scala 3

(tpe: c.Type).typeSymbol

(repr: TypeRepr).typeSymbol

sym.isType / sym.isClass / sym.isModule / sym.isTerm

sym.isType / sym.isClassDef / --- / sym.isTerm

sym.asType, sym.asClass, sym.asModule, sym.asTerm

only 1 kind of Symbol

sym.asClass.primaryConstructor

sym.primaryConstructor

NoSymbol

Symbol.noSymbol

(tpe: c.Type).decls

sym.declaredFields / sym.declaredMethods

(tpe: c.Type).members

sym.fieldMembers / sym.methodMembers

typeParams (Scala 2)

paramLists (Scala 2)

paramSymss (Scala 3)

def method: Unit

List()

List()

List()

def method(): Unit

List()

List(List())

List(List())

def method(a: Int, b: String): Unit

List()

List(List(value a, value b))

List(List(val a, val b))

def method(a: Int)(b:String):Unit

List()

List(List(value a), List(value b))

List(List(val a), List(val b))

def method[A]: Unit

List(type A)

List()

List(List(type A))

def method[A](a: A): Unit

List(type A)

List(value a)

List(List(type A), List(val b))

extension [A](a: A) def method[b](b: B): Unit

List(List(type A), List(val a), List(type B), List(val b))