This repository holds a Scala compiler plugin that will bring parser macros to Scala. This plugin is still a work in progress.
The plugin is not yet published anywhere. You will need to clone this repository and build the plugin yourself. Fortunately, it's pretty straightforward to do using sbt:
$ git clone [email protected]:Duhemm/parsermacro.git
$ cd parsermacro
$ sbt cmp test
You can place your macro implementations in sandbox-macros/ and your macro clients in sandbox-clients/.
This plugin can also be used directly in the Scala REPL after you've built it. To build a self-contained JAR that includes this plugin among with its dependencies (scala.meta), the best is to use sbt:
$ sbt cmp
This will produce a fat JAR in plugin/target/scala-2.11/fat-plugin.jar. To start a Scala REPL with the plugin loaded, simply run:
$ scala -Xplugin:plugin/target/scala-2.11/fat-plugin.jar -cp plugin/target/scala-2.11/fat-plugin.jar
You can then start having fun with parser macros !
Welcome to Scala version 2.11.6 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_31).
Type in expressions to have them evaluated.
Type :help for more information.
scala> import scala.meta._
import scala.meta._
scala> def impl(t: Seq[Token]): Tree = internal.ast.Lit.Int(t.size)
impl: (t: Seq[meta.Token])scala.meta.Tree
scala> def count: Int = macro impl
defined term macro count: Int
scala> count#(Hello, world!)
res0: Int = 7