feat(Cause): add Cause#squashWith

0x706b · Jun 16, 2022 · eecc62c · eecc62c
1 parent a2dde85
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diff --git a/.changeset/clever-impalas-smile.md b/.changeset/clever-impalas-smile.md
@@ -0,0 +1,6 @@
+---
+"@fncts/base": patch
+"@fncts/io": patch
+---
+
+feat(Cause): add Cause#squashWith
diff --git a/packages/base/src/data/Cause/api.ts b/packages/base/src/data/Cause/api.ts
@@ -642,6 +642,15 @@ export function isInterrupt<E>(self: Cause<E>): self is Interrupt {
   return self._tag === CauseTag.Interrupt;
 }
 
+/**
+ * Determines if the `Cause` contains an interruption.
+ *
+ * @tsplus getter fncts.Cause isInterrupted
+ */
+export function isInterrupted<E>(self: Cause<E>): boolean {
+  return self.find((cause) => (cause.isInterrupt() ? Just(cause) : Nothing())).isJust();
+}
+
 /**
  * A type-guard matching `Traced`
  *
@@ -689,8 +698,10 @@ export function interruptOption<E>(self: Cause<E>): Maybe<FiberId> {
  *
  * @tsplus getter fncts.Cause interruptors
  */
-export function interruptors<E>(self: Cause<E>): ReadonlySet<FiberId> {
-  return self.foldLeft(new Set(), (s, c) => (c._tag === CauseTag.Interrupt ? Just(s.add(c.id)) : Nothing()));
+export function interruptors<E>(self: Cause<E>): HashSet<FiberId> {
+  return self.foldLeft(HashSet.makeDefault(), (s, c) =>
+    c._tag === CauseTag.Interrupt ? Just(s.add(c.id)) : Nothing(),
+  );
 }
 
 /**
@@ -915,52 +926,31 @@ export function sequenceCauseMaybe<E>(self: Cause<Maybe<E>>): Maybe<Cause<E>> {
   return Eval.run(sequenceCauseMaybeEval(self));
 }
 
-// /**
-//  * Squashes a `Cause` down to a single `Error`, chosen to be the
-//  * "most important" `Error`.
-//  */
-// export function squash_<Id>(
-//   S: P.Show<Id>
-// ): <E>(cause: Cause<E>, f: (e: E) => unknown) => unknown {
-//   return (cause, f) =>
-//     cause.failureOption
-//       .map(f)
-//       .orElse(
-//         interrupted(cause)
-//           ? Maybe.just<unknown>(
-//               new InterruptedException(
-//                 "Interrupted by fibers: " +
-//                   Array.from(interruptors(cause))
-//                     .map((id) => S.show(id))
-//                     .join(", ")
-//               )
-//             )
-//           : Maybe.nothing()
-//       )
-//       .orElse(defects(cause).head)
-//       .getOrElse(new InterruptedException("Interrupted"));
-// }
-
-// /**
-//  * @tsplus getter PCause squash
-//  */
-// export function squash0<Id, E>(self: Cause<E>) {
-//   return (S: P.Show<Id>) =>
-//     (f: (e: E) => unknown): unknown =>
-//       squash_(S)(self, f);
-// }
-
-// /**
-//  * Squashes a `Cause` down to a single `Error`, chosen to be the
-//  * "most important" `Error`.
-//  *
-//  * @dataFirst squash_
-//  */
-// export function squash<Id>(
-//   S: P.Show<Id>
-// ): <E>(f: (e: E) => unknown) => (cause: Cause<E>) => unknown {
-//   return (f) => (cause) => squash_(S)(cause, f);
-// }
+/**
+ * Squashes a `Cause` down to a single `Error`, chosen to be the
+ * "most important" `Error`.
+ *
+ * @tsplus fluent fncts.Cause squashWith
+ */
+export function squashWith_<E>(self: Cause<E>, f: (e: E) => unknown): unknown {
+  return self.failureMaybe
+    .map(f)
+    .orElse(
+      self.isInterrupted
+        ? Just(
+            new InterruptedException(
+              "Interrupted by fibers: " +
+                self.interruptors
+                  .flatMap((id) => id.ids)
+                  .map((id) => `#${id}`)
+                  .join(", "),
+            ),
+          )
+        : Nothing(),
+    )
+    .orElse(self.defects.head)
+    .getOrElse(new InterruptedException());
+}
 
 /**
  * Constructs a `Cause` from two `Cause`s, representing sequential failures.

diff --git a/packages/base/src/data/exceptions/InterruptedException.ts b/packages/base/src/data/exceptions/InterruptedException.ts
@@ -5,7 +5,7 @@ export type InterruptedExceptionTypeId = typeof InterruptedExceptionTypeId;
 
 export class InterruptedException {
   readonly _typeId: InterruptedExceptionTypeId = InterruptedExceptionTypeId;
-  constructor(readonly message: string) {}
+  constructor(readonly message?: string) {}
 }
 
 export function isInterruptedException(u: unknown): u is InterruptedException {

diff --git a/packages/io/src/IO/api.ts b/packages/io/src/IO/api.ts
@@ -92,15 +92,15 @@ export function asyncInterrupt<R, E, A>(
   return new Async(register, blockingOn, __tsplusTrace);
 }
 
-// /**
-//  * Attempts to convert defects into a failure, throwing away all information
-//  * about the cause of the failure.
-//  *
-//  * @tsplus fluent fncts.io.IO absorbWith
-//  */
-// export function absorbWith_<R, E, A>(ma: IO<R, E, A>, f: (e: E) => unknown, __tsplusTrace?: string) {
-//   return ma.sandbox.matchIO((cause) => IO.failNow(cause.squash(f)), IO.succeedNow)
-// }
+/**
+ * Attempts to convert defects into a failure, throwing away all information
+ * about the cause of the failure.
+ *
+ * @tsplus fluent fncts.io.IO absorbWith
+ */
+export function absorbWith_<R, E, A>(ma: IO<R, E, A>, f: (e: E) => unknown, __tsplusTrace?: string) {
+  return ma.sandbox.matchIO((cause) => IO.failNow(cause.squashWith(f)), IO.succeedNow)
+}
 
 /**
  * @tsplus fluent fncts.io.IO apFirst

diff --git a/packages/io/src/IO/api/interrupt.ts b/packages/io/src/IO/api/interrupt.ts
@@ -96,7 +96,7 @@ export function interruptibleMask<R, E, A>(k: (restore: InterruptStatusRestore)
  */
 export function onInterrupt_<R, E, A, R1>(
   ma: IO<R, E, A>,
-  cleanup: (interruptors: ReadonlySet<FiberId>) => IO<R1, never, any>,
+  cleanup: (interruptors: HashSet<FiberId>) => IO<R1, never, any>,
 ): IO<R & R1, E, A> {
   return uninterruptibleMask(({ restore }) =>
     restore(ma).matchCauseIO(