Gitter Simple Scala Reflection


SMirror is a simpler way to do reflection that provides a higher level of abstraction over the Scala 2.10 runtime reflection.


SMirror usage is not thread-safe, since it uses the Scala Reflection that is also not thread-safe. The API is a subset of the standard reflection, but is possible to access the symbols and mirrors to use the underlying reflection.


Binaries are located at the maven repository:

SBT repository and dependency configuration:

resolvers += "fwbrasil" at ""
libraryDependencies += "net.fwbrasil" %% "smirror" % "0.2"


It is necessary to import the smirror package and to have a implicit runtimeMirror in the scope to use SMirror:

scala> import net.fwbrasil.smirror._
import net.fwbrasil.smirror._

scala> implicit val mirror = runtimeMirror(getClass.getClassLoader)
mirror: reflect.runtime.universe.Mirror = JavaMirror with

An example class:

scala> class Product(val category: String) {
     |     var tags = Set[String]()
     |     def clearTags =
     |         tags = Set()
     | }
defined class Product

Examples of class reflection:

scala> val sClass = sClassOf[Product]
sClass: net.fwbrasil.smirror.SClass[Product] = Product

res0: String = Product

scala> sClass.javaClassOption
res1: Option[Class[Product]] = Some(class Product)

scala> sClass.vals
res2: List[net.fwbrasil.smirror.SVal[Product]] = List(val category: java.lang.String)

scala> sClass.vars
res3: List[net.fwbrasil.smirror.SVar[Product]] = List(var tags: scala.collection.immutable.Set)

scala> sClass.methods
res4: List[net.fwbrasil.smirror.SMethod[Product]] = List(clearTags(): scala.Unit)

scala> sClass.constructors
res5: List[net.fwbrasil.smirror.SConstructor[Product]] = List(<init>(category: java.lang.String): Product)

Examples of constructor and method invocation:

scala> val constructor = sClass.constructors.head
constructor: net.fwbrasil.smirror.SConstructor[Product] = <init>(category: java.lang.String): Product

scala> val product = constructor.invoke("sports")
product: Product = Product@6c6c7d22

scala> val tagsVar = sClass.vars.head
tagsVar: net.fwbrasil.smirror.SVar[Product] = var tags: scala.collection.immutable.Set

scala> tagsVar.set(product, Set("tennis"))
res6: Any = ()

scala> tagsVar.get(product)
res7: Any = Set(tennis)

scala> product.tags
res8: scala.collection.immutable.Set[String] = Set(tennis)

scala> val clearTagsMethod = sClass.methods.head
clearTagsMethod: net.fwbrasil.smirror.SMethod[Product] = clearTags(): scala.Unit

scala> clearTagsMethod.invoke(product)
res9: Any = ()

scala> product.tags
res10: scala.collection.immutable.Set[String] = Set()

Examples of instance reflection:

scala> product.reflect.vals.head.get
res11: Any = sports

scala> product.reflect.vars.head.set(Set("tennis"))
res12: Any = ()

scala> product.tags
res13: scala.collection.immutable.Set[String] = Set(tennis)

scala> product.reflect.methods.head.invoke()
res14: Any = ()

scala> product.tags
res15: scala.collection.immutable.Set[String] = Set()

It is possible to reflect type arguments too:

scala> product.reflect.vars.head.typeArguments
res16: List[net.fwbrasil.smirror.SClass[Any]] = List(java.lang.String)