How to add examples to an SBT project? - scala

Question

I want to add some examples to my Scala library. I prefer a directory layout like this:
examples/
example1/
Main.scala
...
example2/
Main.scala
...
src/
main/
scala/
...
test/
scala/
...
build.sbt
The examples use the packages in src/main/scala/. Is it possible to build and run the examples using SBT? Is it also possible to have dependencies specific to the examples?

Answer 1

It is possible, but you likely have to resort to complete .scala definition. I've put example project on bitbucket.
Here is the showcase:
// [info] Loading global plugins from /Users/omnomnom/.sbt/0.13/plugins
// [info] Loading project definition from /Users/omnomnom/projects/example-of-examples/project
// [info] Set current project to root-project (in build file:/Users/omnomnom/projects/example-of-examples/)
> projects
// [info] In file:/Users/omnomnom/projects/example-of-examples/
// [info] example1
// [info] example2
// [info] * root-project
> project example1
// [info] Set current project to example1 (in build file:/Users/omnomnom/projects/example-of-examples/)
> run
// [info] Updating {file:/Users/omnomnom/projects/example-of-examples/}root-project...
// [info] Resolving org.fusesource.jansi#jansi;1.4 ...
// [info] Done updating.
// [info] Updating {file:/Users/omnomnom/projects/example-of-examples/}example1...
// [info] Resolving org.fusesource.jansi#jansi;1.4 ...
// [info] Done updating.
// [info] Compiling 1 Scala source to /Users/omnomnom/projects/example-of-examples/target/scala-2.10/classes...
// [info] Running Main
I'm example #1
// [success] Total time: 4 s, completed Jul 4, 2014 10:17:54 PM
> project example2
// [info] Set current project to example2 (in build file:/Users/omnomnom/projects/example-of-examples/)
> run
// [info] Updating {file:/Users/omnomnom/projects/example-of-examples/}example2...
// [info] Resolving org.fusesource.jansi#jansi;1.4 ...
// [info] Done updating.
// [info] Compiling 1 Scala source to /Users/omnomnom/projects/example-of-examples/examples/example2/target/scala-2.10/classes...
// [info] Running Main
I'm example #2
// [success] Total time: 3 s, completed Jul 4, 2014 10:18:04 PM
And Build.scala, just for the case:
import sbt._
import Keys._
object Build extends Build {
override lazy val settings = super.settings ++ Seq(
scalacOptions ++= Seq("-unchecked", "-deprecation", "-Xlint"),
organization := "me.lazyval",
scalaVersion := "2.10.4",
initialCommands in console := "import me.lazyval._"
)
// altering source path, since you don't want to replicate usual src/main ... stuff
val exampleSourcePath = scalaSource in Compile := baseDirectory.value / "."
lazy val root = Project(id = "root-project", base = file("."), settings = Project.defaultSettings ++ settings)
lazy val example1 = Project(id = "example1", base = file("./examples/example1"), settings = Project.defaultSettings ++ settings ++ Seq(exampleSourcePath)) dependsOn root
// in `settings= ...` section you can set whatever dependencies you like
lazy val example2 = Project(id = "example2", base = file("./examples/example2"), settings = Project.defaultSettings ++ settings ++ Seq(exampleSourcePath)) dependsOn root
}