From 8b6e959d11a85f4290ae4204296eedda7ae902dd Mon Sep 17 00:00:00 2001
From: Gleb Koval <gleb@koval.net>
Date: Fri, 14 Mar 2025 18:25:35 +0000
Subject: [PATCH] feat: parTraverse -> fs2

---
 project.scala                          |  2 ++
 src/main/wacc/Main.scala               | 11 +++++++++--
 src/main/wacc/frontend/semantics.scala |  2 +-
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/project.scala b/project.scala
index 8edf035..ee9d2f7 100644
--- a/project.scala
+++ b/project.scala
@@ -13,6 +13,8 @@
 //> using dep org.slf4j:slf4j-simple:2.0.17
 //> using test.dep org.scalatest::scalatest::3.2.19
 //> using dep org.typelevel::cats-effect-testing-scalatest::1.6.0
+//> using dep "co.fs2::fs2-core:3.11.0"
+//> using dep co.fs2::fs2-io:3.11.0
 
 // sensible defaults for warnings and compiler checks
 //> using options -deprecation -unchecked -feature
diff --git a/src/main/wacc/Main.scala b/src/main/wacc/Main.scala
index c29de9d..a778a07 100644
--- a/src/main/wacc/Main.scala
+++ b/src/main/wacc/Main.scala
@@ -15,6 +15,8 @@ import com.monovore.decline.effect._
 import org.typelevel.log4cats.slf4j.Slf4jLogger
 import org.typelevel.log4cats.Logger
 
+import fs2.Stream
+
 import assemblyIR as asm
 import cats.data.ValidatedNel
 import java.io.File
@@ -147,8 +149,13 @@ def compileCommandParallel(
     log: Boolean,
     outDir: Option[Path]
 ): IO[ExitCode] =
-  files
-    .parTraverse { file => compile(file.toAbsolutePath, outDir, log) }
+  Stream
+    .emits(files.toList)
+    .parEvalMapUnordered(Runtime.getRuntime.availableProcessors()) { file =>
+      compile(file.toAbsolutePath, outDir, log)
+    }
+    .compile
+    .toList
     .map { exitCodes =>
       exitCodes.filter(_ != 0) match {
         case Nil        => ExitCode.Success
diff --git a/src/main/wacc/frontend/semantics.scala b/src/main/wacc/frontend/semantics.scala
index 9578e8a..6940e45 100644
--- a/src/main/wacc/frontend/semantics.scala
+++ b/src/main/wacc/frontend/semantics.scala
@@ -27,7 +27,7 @@ object semantics {
       toRename = (main +: chunks).toList
       res <- toRename
         .zip(scope.subscopes(toRename.size))
-        .parTraverse(checkFunc)
+        .traverse(checkFunc)
       (typedChunks, errors) = res.foldLeft((Chain.empty[microWacc.FuncDecl], Chain.empty[Error])) {
         case ((acc, err), (funcDecl, errors)) =>
           (acc :+ funcDecl, err ++ errors)