In Scala 2.10, a new reflection library was introduced to add a more powerful toolkit of general reflective capabilities to Scala. Along with full-featured runtime reflection for Scala types and generics, Scala 2.10 also ships with compile-time reflection capabilities, in the form of macros, as well as the ability to reify Scala expressions into abstract syntax trees.
Questions tagged [scala-reflect]
278 questions
0
votes
1 answer
Scala macro does not compile when code is crafted without reify
I've been working on complex compile-time reflection and have come across the need to craft Scala code manually, using the AST. While experimenting I noticed a weird compilation error which doesn't really make sense to me, so I tried reproducing it…
Adi Gerber
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0
votes
2 answers
Scala reflect string to singleton object
I'm looking for a way to convert a Scala singleton object given as a string (for example: package1.Main) to the actual instance of Main, so that I can invoke methods on it.
Example of the problem:
package x {
object Main extends App {
val…
Devabc
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0
votes
1 answer
How to prevent typecheck in StaticAnnotation?
I am creating some macro libraries that reads some information from annotation on the enclosing method.
@info(foo(bar, baz))
def enclosing() = {
myMacro()
}
These information are encoded as foo(bar, baz) in a StaticAnnotation @info.
foo(bar, baz)…
Yang Bo
- 3,586
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votes
1 answer
how to call scala REPL console from scala program?
I need embed Scala REPL functionality in my Scala Application. How can I do that ? Which Scala method/class I need to call ?
I take a look at scala.tools.nsc.interpreter package but I don't see how to do that.
João Paraná
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- 1
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0
votes
1 answer
How to load implicit Manifest from polymorphic type field
I am trying to build an interpreter for my ADT but I don't know how to solve the problem of loading the implicit manifests in a nice way
sealed trait Polymorphic[T]
case class Type1[T: Manifest](field1: T) extends Polymorphic[T]
case class Type2[T:…
Mikel San Vicente
- 3,831
- 2
- 21
- 39
0
votes
1 answer
sbt-android: unable to use scala-reflect on android: java.rmi.Remote not found
I'm trying to use the scala-reflect package for android development.
I have added the scala-reflect dependency in my build.sbt:
libraryDependencies += "org.scala-lang" % "scala-reflect" % "2.11.8"
but I get an…
Bert Becker
- 41
- 5
0
votes
1 answer
Performing an explicit cast based on `Class` instance
Assume there is a class X. At some point in my code, I get an o of type Object and I want to explicitly cast it to X. Normally, I would do val x: X = o.asInstanceOf[X]. However, X is not in scope, all I have is X's instance of Class, like so:
I…
typeduke
- 6,494
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0
votes
2 answers
Scala: get outer class from inner class in constructor
I have an anonymous inner class, and I want to acces the (anonymous) outer class of it in the constructor. So I want to implement this method:
new Outer {
new Inner {
}
}
class Outer {
}
class Inner {
def outerClass: Outer = ???
}
Bert Becker
- 41
- 5
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votes
1 answer
How to access to generic class field via scala-reflect and TypeTag (Scala 2.10)
I am trying to check if a field exists in a generic class.
import scala.reflect.runtime.{universe => ru}
class Example[T:ru.TypeTag](val value:T)
object Example {
def apply[T:ru.TypeTag](value:T, fieldName: String) : Example[T] = {
val t…
Mikel San Vicente
- 3,831
- 2
- 21
- 39
0
votes
1 answer
Testing Scala on Android : "Couldn't find scala.reflect.ScalaSignature.bytes"
I am trying to write instrumentation test in Scala (full code is here).
Any ideas what might be causing the java.lang.IncompatibleClassChangeError: Couldn't find scala.reflect.ScalaSignature.bytes run-time error ?
I am trying to keep…
jhegedus
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0
votes
0 answers
How do I import scala.reflect.io.File into my project?
I am using IntelliJ IDE.
I want to import scala.reflect.io.File from the package - scala-reflect-2.11.4. But when I type in import scala.reflect, the compiler thinks that I am trying to use the class reflect from the package scala-library-2.11.8.…
Soren Goyal
- 196
- 4
0
votes
2 answers
Scala: Using TypeTag in a method
I am trying to write a method like this:
def foo[T:TypeTag](value: Int):String = {
(/* do something */).mapTo[T].map(_.toJson)
}
where mapTo has the signature:
def mapTo[S](implicit tag: ClassTag[S]): Future[S] = { ... }
using…
Randomize
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votes
1 answer
In Scala, How to get the returned TypeTag of a class method?
I have a class:
package org.apache.project
class Foo {
def bar: List[Bar] = ...
}
is it a way in scala reflection that allows me to get typeOf[List[Bar]] from the className "org.apache.project.Foo" and the method name "bar"?
Thanks a lot for your…
tribbloid
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0
votes
0 answers
Passing type information in scala
If I have some class heirarchy defined like this
sealed trait A
case class B() extends A
case class C() extends A
// and so on ..
and in a different location I want to call some method dynamically passing above classes as type to that function
(eg:…
Harsh Gupta
- 339
- 4
- 20
0
votes
2 answers
Obtain Java Class from Scala TypeTag in Macros
According to this question/answer Any way to obtain a Java class from a Scala (2.10) type tag or symbol?
I should use runtimeClass to obtain the Class from a type.
But if I do reflection in Macros I don't have access to runtimeClass.
How can I do?
Joan
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