effekt-lang · b-studios · Jul 30, 2024 · May 7, 2024 · May 28, 2024 · May 28, 2024
diff --git a/effekt/js/src/main/scala/effekt/Backend.scala b/effekt/js/src/main/scala/effekt/Backend.scala
@@ -1,6 +1,6 @@
 package effekt
 
 class Backend {
-  val compiler = generator.js.JavaScript()
+  val compiler = generator.js.JavaScriptWeb()
   val runner = ()
 }
diff --git a/effekt/jvm/src/main/scala/effekt/Backend.scala b/effekt/jvm/src/main/scala/effekt/Backend.scala
@@ -27,7 +27,8 @@ case class Backend[E](name: String, compiler: Compiler[E], runner: Runner[E])
 object Backend {
 
   def backend(name: String): Backend[_] = name match {
-    case "js"           => Backend("js", js.JavaScript(), JSRunner)
+    case "js"           => Backend("js", js.JavaScriptNode(), JSNodeRunner)
+    case "js-web"       => Backend("js-web", js.JavaScriptWeb(), JSWebRunner)
     case "chez-monadic" => Backend("chez-monadic", chez.ChezSchemeMonadic(), ChezMonadicRunner)
     case "chez-callcc"  => Backend("chez-callcc", chez.ChezSchemeCallCC(), ChezCallCCRunner)
     case "chez-lift"    => Backend("chez-lift", chez.ChezSchemeLift(), ChezLiftRunner)

diff --git a/effekt/jvm/src/main/scala/effekt/EffektConfig.scala b/effekt/jvm/src/main/scala/effekt/EffektConfig.scala
@@ -50,7 +50,7 @@ class EffektConfig(args: Seq[String]) extends REPLConfig(args.takeWhile(_ != "--
   )
 
   val backend: ScallopOption[Backend[_]] = choice(
-    choices = List("js", "chez-callcc", "chez-monadic", "chez-lift", "llvm", "ml"),
+    choices = List("js", "js-web", "chez-callcc", "chez-monadic", "chez-lift", "llvm", "ml"),
     name = "backend",
     descr = "The backend that should be used",
     default = Some("js"),

diff --git a/effekt/jvm/src/main/scala/effekt/Runner.scala b/effekt/jvm/src/main/scala/effekt/Runner.scala
@@ -119,7 +119,7 @@ trait Runner[Executable] {
   }
 }
 
-object JSRunner extends Runner[String] {
+object JSNodeRunner extends Runner[String] {
   import scala.sys.process.Process
 
   val extension = "js"
@@ -157,6 +157,43 @@ object JSRunner extends Runner[String] {
         createScript(exePath, "node", jsMainFilePath)
     }
 }
+object JSWebRunner extends Runner[String] {
+  import scala.sys.process.Process
+
+  val extension = "js"
+
+  def standardLibraryPath(root: File): File = root / "libraries" / "common"
+
+  override def prelude: List[String] = List("effekt", "option", "list", "result", "exception", "array", "string", "ref")
+
+  def checkSetup(): Either[String, Unit] =
+    Left("Running js-web code directly is not supported. Use `--compile` to generate a js file / `--build` to generate a html file.")
+
+  /**
+   * Creates an openable `.html` file besides the given `.js` file ([[path]])
+   * and then errors out, printing it's path.
+   */
+  def build(path: String)(using C: Context): String =
+    import java.nio.file.Path
+    val out = C.config.outputPath().getAbsolutePath
+    val jsFilePath = (out / path).unixPath
+    val jsFileName = jsFilePath.split("/").last
+    val htmlFilePath = jsFilePath.stripSuffix(s".$extension") + ".html"
+    val mainName = "$" + jsFileName.stripSuffix(".js") + ".main"
+    val htmlContent =
+      s"""<!DOCTYPE html>
+         |<html>
+         |  <body>
+         |    <script type="text/javascript" src="${jsFileName}"></script>
+         |    <script type="text/javascript">
+         |      window.onload=${mainName};
+         |    </script>
+         |  </body>
+         |</html>
+         |""".stripMargin
+    IO.createFile(htmlFilePath, htmlContent, false)
+    C.abort(s"Open file://${htmlFilePath} in your browser or include ${jsFilePath}.")
+}
 
 trait ChezRunner extends Runner[String] {
   val extension = "ss"

diff --git a/effekt/shared/src/main/scala/effekt/generator/js/JavaScript.scala b/effekt/shared/src/main/scala/effekt/generator/js/JavaScript.scala
@@ -9,13 +9,13 @@ import kiama.output.PrettyPrinterTypes.Document
 import kiama.util.Source
 
 
-class JavaScript extends Compiler[String] {
+class JavaScript(additionalFeatureFlags: List[String] = Nil) extends Compiler[String] {
 
   // Implementation of the Compiler Interface:
   // -----------------------------------------
   def extension = ".js"
 
-  override def supportedFeatureFlags: List[String] = TransformerMonadicWhole.jsFeatureFlags
+  override def supportedFeatureFlags: List[String] = additionalFeatureFlags ++ TransformerMonadicWhole.jsFeatureFlags
 
   override def prettyIR(source: Source, stage: Stage)(using Context): Option[Document] = stage match {
     case Stage.Core => Core(source).map { res => core.PrettyPrinter.format(res.core) }
@@ -62,3 +62,5 @@ class JavaScript extends Compiler[String] {
   private def pretty(stmts: List[js.Stmt]): Document =
     js.PrettyPrinter.format(stmts)
 }
+class JavaScriptWeb extends JavaScript(List("jsWeb")) {}
+class JavaScriptNode extends JavaScript(List("jsNode")) {}
diff --git a/effekt/shared/src/main/scala/effekt/generator/js/Tree.scala b/effekt/shared/src/main/scala/effekt/generator/js/Tree.scala
@@ -43,7 +43,7 @@ case class Module(name: JSName, imports: List[Import], exports: List[Export], st
         js.Destruct(names, js.Call(Variable(JSName("require")), List(JsString(s"./${ file }"))))
     }
 
-    val exportStatement = js.Assign(RawExpr("module.exports"),
+    val exportStatement = js.Assign(RawExpr(s"(typeof module != \"undefined\" && module !== null ? module : {}).exports = ${name.name}"),
       js.Object(exports.map { e => e.name -> e.expr })
     )