From b1c76fe0c31484d76ebcf7a2f6694b60d4c0c9fc Mon Sep 17 00:00:00 2001
From: Jamie Willis <j.willis19@imperial.ac.uk>
Date: Tue, 7 Nov 2023 12:41:17 +0000
Subject: [PATCH] fix: moved where hint restore happens from label to amend

---
 .../main/scala/parsley/internal/deepembedding/Cont.scala    | 1 +
 .../parsley/internal/machine/instructions/ErrorInstrs.scala | 6 ++++--
 parsley/shared/src/test/scala/parsley/ErrorTests.scala      | 2 +-
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/parsley/shared/src/main/scala/parsley/internal/deepembedding/Cont.scala b/parsley/shared/src/main/scala/parsley/internal/deepembedding/Cont.scala
index 4bba457c4..269a3623f 100644
--- a/parsley/shared/src/main/scala/parsley/internal/deepembedding/Cont.scala
+++ b/parsley/shared/src/main/scala/parsley/internal/deepembedding/Cont.scala
@@ -6,6 +6,7 @@
 package parsley.internal.deepembedding
 
 import scala.annotation.tailrec
+
 import org.typelevel.scalaccompat.annotation.uncheckedVariance212
 
 // Trampoline for CPS
diff --git a/parsley/shared/src/main/scala/parsley/internal/machine/instructions/ErrorInstrs.scala b/parsley/shared/src/main/scala/parsley/internal/machine/instructions/ErrorInstrs.scala
index 66ce96b12..93e374f1f 100644
--- a/parsley/shared/src/main/scala/parsley/internal/machine/instructions/ErrorInstrs.scala
+++ b/parsley/shared/src/main/scala/parsley/internal/machine/instructions/ErrorInstrs.scala
@@ -35,7 +35,7 @@ private [internal] final class RelabelHints(labels: Iterable[String]) extends In
 private [internal] final class RelabelErrorAndFail(labels: Iterable[String]) extends Instr {
     override def apply(ctx: Context): Unit = {
         ensureHandlerInstruction(ctx)
-        ctx.restoreHints()
+        //ctx.restoreHints() //FIXME: I'm not sure this was meant to be there in the first place
         ctx.errs.error = ctx.useHints {
             // only use the label if the error message is generated at the same offset
             // as the check stack saved for the start of the `label` combinator.
@@ -45,7 +45,7 @@ private [internal] final class RelabelErrorAndFail(labels: Iterable[String]) ext
         ctx.fail()
     }
     // $COVERAGE-OFF$
-    override def toString: String = s"ApplyError($labels)"
+    override def toString: String = s"RelabelErrorAndFail($labels)"
     // $COVERAGE-ON$
 }
 
@@ -62,6 +62,7 @@ private [internal] object HideHints extends Instr {
     // $COVERAGE-ON$
 }
 
+// FIXME: Gigaparsec points out the hints aren't being used here, I believe they should be!
 private [internal] object HideErrorAndFail extends Instr {
     override def apply(ctx: Context): Unit = {
         ensureHandlerInstruction(ctx)
@@ -119,6 +120,7 @@ private [internal] class ApplyReasonAndFail(reason: String) extends Instr {
 private [internal] class AmendAndFail private (partial: Boolean) extends Instr {
     override def apply(ctx: Context): Unit = {
         ensureHandlerInstruction(ctx)
+        ctx.restoreHints() //TODO: verify this is ok; it feels more right than the restore on the labelling
         ctx.handlers = ctx.handlers.tail
         ctx.errs.error = ctx.errs.error.amend(partial, ctx.states.offset, ctx.states.line, ctx.states.col)
         ctx.states = ctx.states.tail
diff --git a/parsley/shared/src/test/scala/parsley/ErrorTests.scala b/parsley/shared/src/test/scala/parsley/ErrorTests.scala
index d4e8fae35..2f20a5890 100644
--- a/parsley/shared/src/test/scala/parsley/ErrorTests.scala
+++ b/parsley/shared/src/test/scala/parsley/ErrorTests.scala
@@ -209,7 +209,7 @@ class ErrorTests extends ParsleyTest {
         }
     }
 
-    it should "not replace hints if input is consumed" in {
+    it should "suppress hints even if input is consumed" in {
         inside((many(digit).hide <* eof).parse("1e")) {
             case Failure(TestError((1, 2), VanillaError(unex, exs, rs, 1))) =>
                 unex should contain (Raw("e"))