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
2
votes
1 answer
In scala 2 or 3, is it possible to debug implicit resolution process in runtime?
In scala language, implicit resolution is often done in compile-time and sometimes throws obfuscating error information, one famous example of such error is when shapeless Generic throws error information like:
error: could not find implicit value…
tribbloid
- 4,026
- 14
- 64
- 103
2
votes
1 answer
How to get a method return type with scala meta annotation?
I want do a Log annotation use scala meta.Usage simple as:
@Log
def f1(a: Int) {
Future(a + 1) //result is a Future
}
// after parsed ====>
def f1(a: Int) {
Future(a + 1).map{x =>
println(x)
x
}
}
How can I check if…
LoranceChen
- 2,453
- 2
- 22
- 48
2
votes
2 answers
meta-programming to parse json in scala
I need some hints to write a scala program that could read json file and create a case class at run time. As an example if we have json class like -
Employ{
name:{datatype:String, null:false}
age:{datatype:Int, null:true}
…
tesnik03
- 1,324
- 2
- 13
- 23
1
vote
0 answers
Including `munit` tests that are excluded by default
I have an munit test:
package myawesomeproject
import munit.FunSuite
class MySillyTest extends FunSuite {
val theTag = new munit.Tag("tagname")
test("THETEST".tag(theTag)) {
assertEquals(2, 3)
}
}
and in my build.sbt, I want to exclude…
Andrey Tyukin
- 43,673
- 4
- 57
- 93
1
vote
1 answer
Scala SymbolMatcher failing to match import prefix
I'm using the scalafix library to try to convert a project from scalaz to cats, but one particular attempt at removing imports (the first case in the following code) is failing. The relevant bits of code are:
scalafix code:
package fix
import…
Charles_F
- 186
- 2
1
vote
1 answer
Why is scala.meta.Term.Param#toString dropping modifiers?
I'm trying to rename the parameter of an anonymous function using a semantic scalafix plugin. The relevant code looks like this:
case Term.Apply(func, args) =>
args.collect { case Term.Block(List(Term.Function(List(arg), _))) =>
…
Corey Woodfield
- 350
- 2
- 10
1
vote
1 answer
scala.meta parent of parent of Defn.Object
Let it be the following hierarchy:
object X extends Y{
...
}
trait Y extends Z {
...
}
trait Z {
def run(): Unit
}
I parse the scala file containing the X and
I want to know if its parent or grandparent is Z.
I can check for parent as…
Chris
- 549
- 1
- 5
- 18
1
vote
1 answer
How to merge multiple imports in scala?
Assume I have a library a.com. Everytime and in each file, I need to import a lot of package like
import a.com._
import a.com.b._
import a.com.c
import a.com.Implicits._
I don't want to write these code every time in each file of
another…
worldterminator
- 2,968
- 6
- 33
- 52
1
vote
1 answer
How to replace all specific Term.Name expressions in an AST recursively with scalameta?
I would like to replace ALL occurences of specific Term.Name instances in the AST.
Something like:
tree match {
case t @ Term.Name(n) if (n == "bla") => Term.Apply(Term.Select(t, Term.Name("read")), List())
}
However, to achieve this, I will…
Baradé
- 1,290
- 1
- 15
- 35
1
vote
1 answer
How to get the type of a variable with scalameta if the decltpe is empty?
If I have the following type
Defn.Var(mods, pats, decltpe, rhs)
in scalameta it might happen that decltype is set to None for a variable like this:
var x = 10
I still want to know the exact type of the variable x which Scala has inferred without…
Baradé
- 1,290
- 1
- 15
- 35
1
vote
1 answer
Does macroparadise no longer work from the command line?
I am trying to start using the paradise macro plugin, so I have been beginning with the identity macro example from:
https://docs.scala-lang.org/overviews/macros/annotations.html
However, when I try to use the identity annotation I get
error:…
user1063042
- 273
- 2
- 11
1
vote
1 answer
scala.meta.Lit.type does not take parameters
When I run the following:
import scala.meta._
class Test {
val x = q"1"
}
I get scala.meta.Lit.type does not take parameters val x = q"1"
scalameta_2.11:1.8.0
paradise_2.11.8:3.0.0-M7
I'm trying to get some basic macro examples working,…
user2682459
- 999
- 2
- 13
- 24
1
vote
1 answer
Generate a case class with Binding.scala Vars using Scala.meta throws an exception
I have a scala.js project. There I have a strange behavior with Scala.Meta and Binding.scala.
I want to create a case class from a case class:
case class SimpleCaseClass(i: Int, s: String, list: Seq[String])
should generate…
pme
- 14,156
- 3
- 52
- 95
1
vote
1 answer
Initializing the factory at compile time
I have a factory that should return an implementation depending on the name.
val moduleMap = Map(Modules.moduleName -> new ModuleImpl)
def getModule(moduleName: String): Module =
moduleMap.get(moduleName) match {
case…
user2607928
- 39
- 7
1
vote
2 answers
Scala macro to auto generate fluent builders
I am interacting with an external Java API which looks like this:
val obj: SomeBigJavaObj = {
val _obj = new SomeBigJavaObj(p1, p2)
_obj.setFoo(p3)
_obj.setBar(p4)
val somethingElse = {
val _obj2 = new SomethingElse(p5)
…
pathikrit
- 32,469
- 37
- 142
- 221