For meta programming in Scala using the Scalameta library
This tag is for questions relating to the Scalameta library for Scala.
Questions tagged [scalameta]
66 questions
0
votes
2 answers
How to get the (static) type of an expression in Scala?
Does Scala have any equivalent to GCC's typeofextension? (Or C++ decltype?)
I'm generating code that references some external code (which may not be available yet), and I need a way to reference the type of that code in a method definition
For…
aij
- 5,903
- 3
- 37
- 41
0
votes
2 answers
How does one obtain the type of the value that an AST represents?
I’m trying to write the following:
import scala.reflect.runtime.universe._
val value: Tree = /* some AST */
val tpe = typeOf(value) // This should be the result type of the AST.
// This is pseudocode. What should
…
Dan Li
- 866
- 1
- 7
- 19
0
votes
1 answer
How does one use quasiquotes to obtain the type of a value?
I’m trying to write the following:
val value: Int = 3
val tpe = typeOf(value) // This is pseudocode. What should
// actually go on this line?
q"""
type U = $tpe
val v: U = $value
"""
Essentially, I need to capture the…
Dan Li
- 866
- 1
- 7
- 19
0
votes
1 answer
Obtaining a SemanticDocument from a Scala source file using ScalaFix
What are the steps of parsing a Scala source file into a SemanticDocument using ScalaFix?
Gakuo
- 845
- 6
- 26
0
votes
1 answer
object contrib is not a member of package meta
I am trying to use the isEqual method in ScalaMeta.
import scala.meta.contrib._
q"true".isEqual(q"true")
The import does not work:
object contrib is not a member of package meta
I am using sbt and I have the following in my…
Gakuo
- 845
- 6
- 26
0
votes
1 answer
Scala Meta: Confused about the versions
In the tutorial you find 2 versions for Scala-Meta.
lazy val MetaVersion = "3.7.2"
lazy val MetaVersion1 = "1.8.0"
I am a bit confused as they seem to refer the same project:
lazy val scalameta1 = "org.scalameta" %% "scalameta" % MetaVersion1
lazy…
pme
- 14,156
- 3
- 52
- 95
0
votes
1 answer
make creating non-native JS trait instances easier in scala.js with scala.meta
I create alot of non-native JS trait instances as parameters to javascript functions
trait ElementOpts extends js.Object {
val prop1: js.UndefOr[String] = js.undefined
// another 10-15 vals
}
To create an instance:
createElement(new ElementOpts…
user1763729
- 167
- 1
- 11
0
votes
1 answer
Lifting string with Scalameta
I would like injecting a method 'toCSV' to parse a class into CSV String. My function take two paramters :
Seq[String] : header
Seq[Seq[Any]] : fields
My macro :
class model extends scala.annotation.StaticAnnotation {
inline def apply(defn:…
user2931656
- 253
- 2
- 3
- 13
0
votes
1 answer
Passing parameters to scalameta paradise macro
I am trying to create a macro annotation but I need to pass it parameters.
class ToPojo(param1: String, param2: String) extends StaticAnnotation {
inline def apply(defn: Any): Any = meta {
...
}
}
which is used as
@ToPojo("p1",…
Vojtech Letal
- 2,168
- 3
- 13
- 17
0
votes
1 answer
scala-meta: parse vararg in class constructor
How can I parse a Term as shown below and extract the arguments parsed to the class apply method. The class apply method takes a variable argument and hence it is not known how many arguments are present in the class constructor.…
rogue-one
- 11,259
- 7
- 53
- 75
0
votes
1 answer
Scala-meta for instrumentation
I noticed that scala-meta provides transformation functions, but not functions to insert additional code (e.g., import statements, or a method call at every start of a function).
Since all structures (scala.meta.Tree and its children) are immutable,…
Captain Obvious
- 745
- 3
- 17
- 39
0
votes
1 answer
Parsing a method definition string, don't know how to parse into scala.meta.Decl.Def
I want to be able to parse a string to Decl.Def but the code doesn't compile:
import scala.meta._
val s:String = ... known only at runtime
s.parse[Decl.Def].get
Error:(39, 52) don't know how to parse into scala.meta.Decl.Def
What do I need to do to…
kostas.kougios
- 945
- 10
- 21
0
votes
1 answer
Defining implicit encoder using scala meta and quasiquotes
I am trying to create an implicit encoder using Circe. However this encoder will be created using an annotation hence I am using Scalameta. Here is my code. However, the compiler complains about having an override statement within quasiquotes.
class…
igalbenardete
- 207
- 2
- 12
0
votes
1 answer
Find method in scala reflect by it's bytecode name
Is there a way to find a method by it's bytecode name?
For example, I would like to find a reference to println(Object) by string "_root_.scala.Predef.println(Ljava/lang/Object;)V."
Daniyar Itegulov
- 1
- 2
0
votes
1 answer
How do I pass an argument to the macro annotation?
I want get StaticAnnotation's parameters defined as:
class Log(logTag: List[LogTag] = Info() :: Nil )
(implicit logger: String => Unit = a => {println(a)})
extends scala.annotation.StaticAnnotation {
inline def apply(defn: Any): Any =…
LoranceChen
- 2,453
- 2
- 22
- 48