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How do I import a package into Scala's REPL? I am trying to import this package called funsets which has an object named "FunSets". I tried several variations of import funsets._ and import funsets._; etc but it is still not importing the functions and object in the package.

Linkx_lair
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  • What is funsets? Is it in a jar? Is it a compiled class file? Is it a scala file? Is it a managed dependency in an external repository like maven central? – Dylan Nissley Dec 18 '17 at 19:35
  • funsets is the name of the package that has an object called FunSets in it. It is just in a scala object file. – Linkx_lair Dec 18 '17 at 19:41
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    You need to run `console` from *within the sbt shell*. Then, sbt will compile whatever is defined in funsets and automatically add it in your Scala shell. From there, you'll be able to do `import funsets._`. – Jorge Dec 19 '17 at 23:35

3 Answers3

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One way is to compile the "scala classes" and put those in classpath.

Example,

1) Say you have a class funsets.FunSets.scala

package funsets                                                                                        

object FunSets {                                                                                       

  def fun = "very fun"                                                                                 

}

2) Compile the class first using scalac. (If you use sbt then sbt compile would put compiled classes in target/ folder)

scalac FunSets.scala

You will see the funsets folder/package created, 

$ ls -l
total 16
-rw-r--r--  1 updupd  NA\Domain Users   63 Dec 18 11:05 FunSets.scala
drwxr-xr-x  4 updupd  NA\Domain Users  136 Dec 18 11:06 funsets

3) Then start REPL with funsets package in classpath 

$ scala -classpath .
Welcome to Scala 2.12.3 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_151).
Type in expressions for evaluation. Or try :help.

scala> import funsets._
import funsets._

Note: if you use sbt compile, put target/classes in classpath.

Access Funsets singleton,

scala> FunSets.fun
res0: String = very fun

Also read Scala REPL unable to import packge

prayagupa
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You need to add the appropriate jar(s) to the classpath as well using the -cp <jar files> argument when starting the repl. Alternatively you can use the :require <jar file> directive from the repl to load a jar after you've already started the session.

puhlen
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2

Assuming you have some code in a scala file, you can load external scala files from the scala repl using the :load command. More info in this answer.

Dylan Nissley
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  • In the REPL, I tried doing `:load "C:...full file path name` and whole bunch of variations. I even tried doing `:paste "full file path name" But it keeps saying like "usage: :load -v file" or "usage: :paste -raw file" – Linkx_lair Dec 18 '17 at 20:26
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    If you start the repl in the same directory as your file you should be able to just do `:load myFile.scala`. – Dylan Nissley Dec 18 '17 at 21:27
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    According to [this answer](https://stackoverflow.com/questions/35070783/load-a-scala-file-from-command-line), you might have to use the `:lo` command instead of `:load`, in windows even though it should have the same behavior. – Dylan Nissley Dec 18 '17 at 21:29