Add initial ANTLR setup + lex/parser

worldedit-core/build.gradle.kts

@@ -1,7 +1,10 @@
+import org.gradle.plugins.ide.idea.model.IdeaModel
+
 plugins {
     id("java-library")
     id("net.ltgt.apt-eclipse")
     id("net.ltgt.apt-idea")
+    id("antlr")
 }
 
 applyPlatformAndCoreConfiguration()
@@ -23,6 +26,10 @@ dependencies {
     "compile"("org.slf4j:slf4j-api:1.7.26")
     "compile"("it.unimi.dsi:fastutil:8.2.1")
 
+    val antlrVersion = "4.7.2"
+    "antlr"("org.antlr:antlr4:$antlrVersion")
+    "implementation"("org.antlr:antlr4-runtime:$antlrVersion")
+
     "compileOnly"(project(":worldedit-libs:core:ap"))
     "annotationProcessor"(project(":worldedit-libs:core:ap"))
     // ensure this is on the classpath for the AP
@@ -36,6 +43,26 @@ tasks.withType<JavaCompile>().configureEach {
     options.compilerArgs.add("-Aarg.name.key.prefix=")
 }
 
+tasks.named<AntlrTask>("generateGrammarSource").configure {
+    val pkg = "com.sk89q.worldedit.antlr"
+    outputDirectory = file("build/generated-src/antlr/main/${pkg.replace('.', '/')}")
+    arguments = listOf(
+        "-visitor", "-package", pkg,
+        "-Xexact-output-dir"
+    )
+}
+
+// Give intellij info about where ANTLR code comes from
+plugins.withId("idea") {
+    configure<IdeaModel> {
+        afterEvaluate {
+            module.sourceDirs.add(file("src/main/antlr"))
+            module.sourceDirs.add(file("build/generated-src/antlr/main"))
+            module.generatedSourceDirs.add(file("build/generated-src/antlr/main"))
+        }
+    }
+}
+
 sourceSets {
     main {
         java {