fixed stack safety issues for pure values

README.md

@@ -22,7 +22,7 @@ You can also check out [this presentation](http://bit.ly/eff_flatmap_2016) at fl
 
 You add `eff` as an sbt dependency:
 ```scala
-libraryDependencies += "org.atnos" %% "eff" % "4.0.0"
+libraryDependencies += "org.atnos" %% "eff" % "4.0.1"
 
 // to write types like Reader[String, ?]
 addCompilerPlugin("org.spire-math" %% "kind-projector" % "0.9.3")

jvm/src/test/scala/org/atnos/eff/ErrorEffectSpec.scala

@@ -5,6 +5,7 @@ import ErrorEffect.{ok => OK, ErrorOrOk}
 
 import scala.collection.mutable.ListBuffer
 import cats.data._
+import cats.implicits._
 import cats.Eval
 import org.atnos.eff.all._
 import org.atnos.eff.syntax.all._
@@ -24,6 +25,8 @@ class ErrorEffectSpec extends Specification { def is = s2"""
  A thrown exception can be ignored $ignored
 
  An action with a given failure type can be translated to an action with another failure type $local
+
+ The error effect is stack-safe $stackSafety
 """
 
   type R = Fx.fx1[ErrorOrOk]
@@ -138,5 +141,12 @@ class ErrorEffectSpec extends Specification { def is = s2"""
     ErrorEffect2.runError(action2[Fx.fx1[ErrorOrOk2]]).run ==== Left(Right(Error2(Error1("boom"))))
   }
 
+  def stackSafety = {
+    val list = (1 to 5000).toList
+    val action = list.traverse(i => ErrorEffect.ok(i.toString))
+
+    ErrorEffect.runError(action).run ==== Right(list.map(_.toString))
+  }
+
 }
 

jvm/src/test/scala/org/atnos/eff/FutureEffectSpec.scala

@@ -34,8 +34,9 @@ class FutureEffectSpec(implicit ee: ExecutionEnv) extends Specification with Sca
  Attempted Future calls with timeout can be memoized $e12
 
  TimedFuture calls can be memoized with a memo effect $e13
- addLast can be used to make sure an action executes when a future fails $e11
+ addLast can be used to make sure an action executes when a future fails $e14
 
+ Future effects can be detached safely with detachA $e15
 
 """
 
@@ -179,6 +180,12 @@ class FutureEffectSpec(implicit ee: ExecutionEnv) extends Specification with Sca
     lastActionDone must beTrue
   }
 
+  def e15 = {
+    val list = (1 to 5000).toList
+    val action = list.traverse(i => futureDelay(i)).detach
+    action.runNow(scheduler, ee.executionContext) must be_===(list).awaitFor(1 second)
+  }
+
   /**
    * HELPERS
    */

notes/4.0.1.markdown

@@ -0,0 +1,6 @@
+Stack-safety fixes.
+
+The stack-safety sage continues.
+
+ * fixed a stack-safety issue when running a interpreting pure values
+ * fixed a stack-safety issue when injecting an effect into a larger stack with `into`

shared/src/main/scala/org/atnos/eff/Eff.scala

@@ -149,7 +149,7 @@ trait EffImplicits {
     override def map[A, B](fa: Eff[AnyRef, A])(f: A => B): Eff[AnyRef, B] =
       fa match {
         case Pure(a, l) =>
-          pure(f(a)).addLast(l)
+          Impure(NoEffect(a), Continuation.unit.map(f), l)
 
         case Impure(union, continuation, last) =>
           Impure(union, continuation map f, last)
@@ -366,17 +366,17 @@ trait EffInterpretation {
       case Impure(u: Union[_, _], continuation, last) =>
         val ta = u.tagged.valueUnsafe.asInstanceOf[M[A]]
         last match {
-          case Last(Some(l)) => ta.map(x => Left(continuation(x).addLast(last)))
-          case Last(None)    => ta.map(x => Left(continuation(x)))
+          case Last(Some(l)) => ta.map(x => Left(Impure(NoEffect(x.asInstanceOf[Any]), continuation, last)))
+          case Last(None)    => ta.map(x => Left(Impure(NoEffect(x.asInstanceOf[Any]), continuation)))
         }
 
       case ap @ ImpureAp(unions, continuation, last) =>
         val effects = unions.unions.map(_.tagged.valueUnsafe.asInstanceOf[M[Any]])
         val sequenced = applicative.sequence(effects)
 
         last match {
-          case Last(Some(_)) => sequenced.map(x => Left(continuation(x).addLast(last)))
-          case Last(None)    => sequenced.map(x => Left(continuation(x)))
+          case Last(Some(_)) => sequenced.map(xs => Left(Impure(NoEffect(xs), continuation, last)))
+          case Last(None)    => sequenced.map(xs => Left(Impure(NoEffect(xs), continuation)))
         }
     }
 
@@ -387,7 +387,7 @@ trait EffInterpretation {
     eff match {
       case Pure(a, Last(Some(l)))     => l.value; Option(a)
       case Pure(a, _)                 => Option(a)
-      case Impure(NoEffect(a), c, l) => runPure(c(a).addLast(l))
+      case Impure(NoEffect(a), c, l)  => runPure(c(a).addLast(l))
       case _                          => None
     }
 

shared/src/main/scala/org/atnos/eff/Interpret.scala

@@ -74,7 +74,7 @@ trait Interpret {
         interpreter.onPure(a).addLast(interpretLast(last))
 
       case Impure(NoEffect(a), c, last) =>
-        runInterpreter(c(a).addLast(last))(interpreter)
+        Impure(NoEffect(a), interpretContinuation(c), interpretLast(last))
 
       case Impure(u: Union[_,_], c, last) =>
         m.project(u) match {

shared/src/main/scala/org/atnos/eff/Unions.scala

@@ -136,7 +136,7 @@ trait UnionInto[R, S] {
         Eff.pure(a).addLast(last.interpret(into))
 
       case Impure(NoEffect(a), c, l) =>
-        into(c(a).addLast(l))
+        Impure(NoEffect(a), c.interpretEff(into)(into), l.interpret(into))
 
       case Impure(u: Union[_, _], c, l) =>
         Impure(apply(u), c.interpretEff(into)(into), l.interpret(into))

try-eff.sh

@@ -2,7 +2,7 @@
 test -e ~/.coursier/cr || (mkdir -p ~/.coursier && wget -q -O ~/.coursier/cr https://git.io/vgvpD && chmod +x ~/.coursier/cr)
 CLASSPATH="$(~/.coursier/cr fetch -q -p \
   \
-  org.atnos:eff_2.12:4.0.0 \
+  org.atnos:eff_2.12:4.0.1 \
   com.lihaoyi:ammonite_2.12.1:0.8.1 \
   \
 )" java ammonite.Main --predef 'import org.atnos.eff._, all._, syntax.all._'

version.sbt

@@ -1 +1 @@
-version in ThisBuild := "4.0.0"
+version in ThisBuild := "4.0.1"