Added CaretWidth datatype, which will be used to deal with fail that …

…can have caret width affected

parsley/shared/src/main/scala/parsley/errors/combinator.scala

@@ -6,6 +6,7 @@ package parsley.errors
 import parsley.Parsley
 
 import parsley.internal.deepembedding.{frontend, singletons}
+import parsley.internal.errors.{CaretWidth, FlexibleCaret, RigidCaret}
 
 /** This module contains combinators that can be used to directly influence error messages of parsers.
   *
@@ -52,7 +53,7 @@ object combinator {
       * @since 3.0.0
       * @group fail
       */
-    def fail(msg0: String, msgs: String*): Parsley[Nothing] = fail(1, msg0, msgs: _*)
+    def fail(msg0: String, msgs: String*): Parsley[Nothing] = fail(new FlexibleCaret(1), msg0, msgs: _*)
 
     /** This combinator consumes no input and fails immediately with the given error messages.
       *
@@ -70,7 +71,8 @@ object combinator {
       * @since 4.0.0
       * @group fail
       */
-    def fail(caretWidth: Int, msg0: String, msgs: String*): Parsley[Nothing] = new Parsley(new singletons.Fail(caretWidth, (msg0 +: msgs): _*))
+    def fail(caretWidth: Int, msg0: String, msgs: String*): Parsley[Nothing] = fail(new RigidCaret(caretWidth), msg0, msgs: _*)
+    private def fail(caretWidth: CaretWidth, msg0: String, msgs: String*): Parsley[Nothing] = new Parsley(new singletons.Fail(caretWidth, (msg0 +: msgs): _*))
 
     /** This combinator consumes no input and fails immediately, setting the unexpected component
       * to the given item.

parsley/shared/src/main/scala/parsley/internal/deepembedding/singletons/ErrorEmbedding.scala

@@ -4,13 +4,14 @@
 package parsley.internal.deepembedding.singletons
 
 import parsley.internal.deepembedding.backend.MZero
+import parsley.internal.errors.CaretWidth
 import parsley.internal.machine.instructions
 
-private [parsley] final class Fail(width: Int, msgs: String*) extends Singleton[Nothing] with MZero {
+private [parsley] final class Fail(width: CaretWidth, msgs: String*) extends Singleton[Nothing] with MZero {
     // $COVERAGE-OFF$
     override def pretty: String = s"fail(${msgs.mkString(", ")})"
     // $COVERAGE-ON$
-    override def instr: instructions.Instr = new instructions.Fail(width: Int, msgs: _*)
+    override def instr: instructions.Instr = new instructions.Fail(width, msgs: _*)
 }
 
 private [parsley] final class Unexpected(msg: String, width: Int) extends Singleton[Nothing] with MZero {

parsley/shared/src/main/scala/parsley/internal/errors/CaretWidth.scala

@@ -0,0 +1,10 @@
+/* SPDX-FileCopyrightText: © 2023 Parsley Contributors <https://github.com/j-mie6/Parsley/graphs/contributors>
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+package parsley.internal.errors
+
+private [parsley] sealed abstract class CaretWidth {
+    def width: Int
+}
+private [parsley] class FlexibleCaret(val width: Int) extends CaretWidth
+private [parsley] class RigidCaret(val width: Int) extends CaretWidth

parsley/shared/src/main/scala/parsley/internal/machine/Context.scala

@@ -11,7 +11,7 @@ import parsley.Result
 import parsley.Success
 import parsley.errors.ErrorBuilder
 
-import parsley.internal.errors.{ExpectItem, LineBuilder, UnexpectDesc}
+import parsley.internal.errors.{CaretWidth, ExpectItem, LineBuilder, UnexpectDesc}
 import parsley.internal.machine.errors.{
     ClassicExpectedError, ClassicFancyError, ClassicUnexpectedError, DefuncError,
     DefuncHints, EmptyHints, ErrorItemBuilder, MultiExpectedError
@@ -200,7 +200,7 @@ private [parsley] final class Context(private [machine] var instrs: Array[Instr]
         }
     }
 
-    private [machine] def failWithMessage(caretWidth: Int, msgs: String*): Unit = this.fail(new ClassicFancyError(offset, line, col, caretWidth, msgs: _*))
+    private [machine] def failWithMessage(caretWidth: CaretWidth, msgs: String*): Unit = this.fail(new ClassicFancyError(offset, line, col, caretWidth, msgs: _*))
     private [machine] def unexpectedFail(expected: Option[ExpectItem], unexpected: UnexpectDesc): Unit = {
         this.fail(new ClassicUnexpectedError(offset, line, col, expected, unexpected))
     }

parsley/shared/src/main/scala/parsley/internal/machine/errors/DefuncBuilders.scala

@@ -5,7 +5,7 @@ package parsley.internal.machine.errors
 
 import scala.collection.mutable
 
-import parsley.internal.errors.{EndOfInput, ExpectItem, FancyError, TrivialError, UnexpectItem}
+import parsley.internal.errors.{EndOfInput, ExpectItem, FancyError, TrivialError, UnexpectDesc, UnexpectItem}
 
 import TrivialErrorBuilder.{BuilderUnexpectItem, NoItem, Other, Raw}
 
@@ -48,7 +48,7 @@ private [errors] final class TrivialErrorBuilder(offset: Int, outOfRange: Boolea
       *
       * @param item
       */
-    def updateUnexpected(item: UnexpectItem): Unit = updateUnexpected(new Other(item))
+    def updateUnexpected(item: UnexpectDesc): Unit = updateUnexpected(new Other(item))
     /** Updates the unexpected (but empty) token generated by the error, so long as no other error item
       * has been used.
       * @param width

parsley/shared/src/main/scala/parsley/internal/machine/errors/DefuncError.scala

@@ -5,7 +5,7 @@ package parsley.internal.machine.errors
 
 import parsley.XAssert._
 
-import parsley.internal.errors.{ExpectDesc, ExpectItem, FancyError, ParseError, TrivialError, UnexpectDesc}
+import parsley.internal.errors.{CaretWidth, ExpectDesc, ExpectItem, FancyError, ParseError, TrivialError, UnexpectDesc}
 
 // This file contains the defunctionalised forms of the error messages.
 // Essentially, whenever an error is created in the machine, it should make use of one of
@@ -293,12 +293,13 @@ private [parsley] final class ClassicUnexpectedError(val offset: Int, val line:
         builder.updateUnexpected(unexpected)
     }
 }
-private [parsley] final class ClassicFancyError(val offset: Int, val line: Int, val col: Int, caretWidth: Int, val msgs: String*) extends FancyDefuncError {
+
+private [parsley] final class ClassicFancyError(val offset: Int, val line: Int, val col: Int, caretWidth: CaretWidth, val msgs: String*) extends FancyDefuncError {
     override final val flags = DefuncError.ExpectedEmptyMask
     override def makeFancy(builder: FancyErrorBuilder): Unit = {
         builder.pos_=(line, col)
         builder ++= msgs
-        builder.updateCaretWidth(caretWidth)
+        builder.updateCaretWidth(caretWidth.width)
     }
 }
 private [parsley] final class EmptyError(val offset: Int, val line: Int, val col: Int, val unexpectedWidth: Int) extends BaseError {

parsley/shared/src/main/scala/parsley/internal/machine/instructions/ErrorInstrs.scala

@@ -3,7 +3,7 @@
  */
 package parsley.internal.machine.instructions
 
-import parsley.internal.errors.UnexpectDesc
+import parsley.internal.errors.{CaretWidth, RigidCaret, UnexpectDesc}
 import parsley.internal.machine.Context
 import parsley.internal.machine.XAssert._
 import parsley.internal.machine.errors.{ClassicExpectedError, ClassicExpectedErrorWithReason, ClassicFancyError, EmptyError}
@@ -141,7 +141,7 @@ private [internal] object SetLexicalAndFail extends Instr {
     // $COVERAGE-ON$
 }
 
-private [internal] final class Fail(width: Int, msgs: String*) extends Instr {
+private [internal] final class Fail(width: CaretWidth, msgs: String*) extends Instr {
     override def apply(ctx: Context): Unit = {
         ensureRegularInstruction(ctx)
         ctx.failWithMessage(width, msgs: _*)
@@ -177,7 +177,7 @@ private [internal] class MakeVerifiedError private (msggen: Either[Any => Seq[St
         val caretWidth = ctx.offset - state.offset
         val x = ctx.stack.upeek
         val err = msggen match {
-            case Left(f) => new ClassicFancyError(state.offset, state.line, state.col, caretWidth, f(x): _*)
+            case Left(f) => new ClassicFancyError(state.offset, state.line, state.col, new RigidCaret(caretWidth), f(x): _*)
             case Right(Some(f)) => new ClassicExpectedErrorWithReason(state.offset, state.line, state.col, None, f(x), caretWidth)
             case Right(None) => new ClassicExpectedError(state.offset, state.line, state.col, None, caretWidth)
         }

parsley/shared/src/main/scala/parsley/internal/machine/instructions/IntrinsicInstrs.scala

@@ -7,7 +7,7 @@ import scala.annotation.tailrec
 
 import parsley.token.errors.LabelConfig
 
-import parsley.internal.errors.{EndOfInput, ExpectDesc, ExpectItem, UnexpectDesc}
+import parsley.internal.errors.{EndOfInput, ExpectDesc, ExpectItem, RigidCaret, UnexpectDesc}
 import parsley.internal.machine.Context
 import parsley.internal.machine.XAssert._
 import parsley.internal.machine.errors.{ClassicFancyError, ClassicUnexpectedError, DefuncError, EmptyError, EmptyErrorWithReason}
@@ -248,7 +248,7 @@ private [internal] final class GuardAgainst(pred: PartialFunction[Any, Seq[Strin
         if (pred.isDefinedAt(ctx.stack.upeek)) {
             val state = ctx.states
             val caretWidth = ctx.offset - state.offset
-            ctx.fail(new ClassicFancyError(state.offset, state.line, state.col, caretWidth, pred(ctx.stack.upop()): _*))
+            ctx.fail(new ClassicFancyError(state.offset, state.line, state.col, new RigidCaret(caretWidth), pred(ctx.stack.upop()): _*))
         }
         else ctx.inc()
         ctx.states = ctx.states.tail

parsley/shared/src/main/scala/parsley/token/errors/ConfigImplTyped.scala

@@ -7,7 +7,7 @@ import parsley.Parsley
 import parsley.XCompat.unused
 import parsley.errors.combinator, combinator.ErrorMethods
 
-import parsley.internal.errors.UnexpectDesc
+import parsley.internal.errors.{RigidCaret, UnexpectDesc}
 import parsley.internal.machine.errors.{ClassicFancyError, ClassicUnexpectedError, DefuncError, EmptyError, EmptyErrorWithReason}
 
 /** This trait, and its subclasses, can be used to configure how filters should be used within the `Lexer`.
@@ -53,7 +53,7 @@ abstract class SpecialisedMessage[A] extends SpecialisedFilterConfig[A] { self =
     }
     private [parsley] final override def collect[B](p: Parsley[A])(f: PartialFunction[A, B]) = p.collectMsg(message(_))(f)
     private [parsley] final override def mkError(offset: Int, line: Int, col: Int, caretWidth: Int, x: A): DefuncError = {
-        new ClassicFancyError(offset, line, col, caretWidth, message(x): _*)
+        new ClassicFancyError(offset, line, col, new RigidCaret(caretWidth), message(x): _*)
     }
 
     // $COVERAGE-OFF$

parsley/shared/src/test/scala/parsley/internal/machine/errors/DefuncErrorTests.scala

@@ -5,7 +5,7 @@ package parsley.internal.machine.errors
 
 import parsley.ParsleyTest
 
-import parsley.internal.errors.{TrivialError, FancyError, ExpectRaw, ExpectDesc, EndOfInput, UnexpectDesc}
+import parsley.internal.errors.{TrivialError, FancyError, ExpectRaw, ExpectDesc, EndOfInput, RigidCaret, UnexpectDesc}
 
 import MockedBuilders.mockedErrorItemBuilder
 
@@ -41,12 +41,12 @@ class DefuncErrorTests extends ParsleyTest {
     }
 
     "ClassicFancyError" should "evaluate to FancyError" in {
-        val err = new ClassicFancyError(0, 0, 0, 1, "")
+        val err = new ClassicFancyError(0, 0, 0, new RigidCaret(1), "")
         err.isTrivialError shouldBe false
         err.asParseError shouldBe a [FancyError]
     }
     it should "always be empty" in {
-        new ClassicFancyError(0, 0, 0, 1, "hi").isExpectedEmpty shouldBe true
+        new ClassicFancyError(0, 0, 0, new RigidCaret(1), "hi").isExpectedEmpty shouldBe true
     }
 
     "EmptyError" should "evaluate to TrivialError" in {
@@ -77,36 +77,37 @@ class DefuncErrorTests extends ParsleyTest {
         err.asParseError shouldBe a [TrivialError]
     }
     they should "be a trivial error if one trivial child is further than the other fancy child" in {
-        val err1 = new EmptyError(1, 0, 0, 0).merge(new ClassicFancyError(0, 0, 0, 1, ""))
+        val err1 = new EmptyError(1, 0, 0, 0).merge(new ClassicFancyError(0, 0, 0, new RigidCaret(1), ""))
         err1.isTrivialError shouldBe true
         err1.asParseError shouldBe a [TrivialError]
 
-        val err2 = new ClassicFancyError(0, 0, 0, 1, "").merge(new EmptyError(1, 0, 0, 0))
+        val err2 = new ClassicFancyError(0, 0, 0, new RigidCaret(1), "").merge(new EmptyError(1, 0, 0, 0))
         err2.isTrivialError shouldBe true
         err2.asParseError shouldBe a [TrivialError]
     }
+    // TODO: tests for flexible carets
     they should "be a fancy error in any other case" in {
-        val err1 = new EmptyError(0, 0, 0, 0).merge(new ClassicFancyError(0, 0, 0, 1, ""))
+        val err1 = new EmptyError(0, 0, 0, 0).merge(new ClassicFancyError(0, 0, 0, new RigidCaret(1), ""))
         err1.isTrivialError shouldBe false
         err1.asParseError shouldBe a [FancyError]
 
-        val err2 = new ClassicFancyError(0, 0, 0, 1, "").merge(new EmptyError(0, 0, 0, 0))
+        val err2 = new ClassicFancyError(0, 0, 0, new RigidCaret(1), "").merge(new EmptyError(0, 0, 0, 0))
         err2.isTrivialError shouldBe false
         err2.asParseError shouldBe a [FancyError]
 
-        val err3 = new EmptyError(0, 0, 0, 0).merge(new ClassicFancyError(1, 0, 0, 1, ""))
+        val err3 = new EmptyError(0, 0, 0, 0).merge(new ClassicFancyError(1, 0, 0, new RigidCaret(1), ""))
         err3.isTrivialError shouldBe false
         err3.asParseError shouldBe a [FancyError]
 
-        val err4 = new ClassicFancyError(1, 0, 0, 1, "").merge(new EmptyError(0, 0, 0, 0))
+        val err4 = new ClassicFancyError(1, 0, 0, new RigidCaret(1), "").merge(new EmptyError(0, 0, 0, 0))
         err4.isTrivialError shouldBe false
         err4.asParseError shouldBe a [FancyError]
 
-        val err5 = new ClassicFancyError(0, 0, 0, 1, "").merge(new ClassicFancyError(0, 0, 0, 1, ""))
+        val err5 = new ClassicFancyError(0, 0, 0, new RigidCaret(1), "").merge(new ClassicFancyError(0, 0, 0, new RigidCaret(1), ""))
         err5.isTrivialError shouldBe false
         err5.asParseError shouldBe a [FancyError]
 
-        val err6 = new ClassicFancyError(1, 0, 0, 1, "").merge(new ClassicFancyError(0, 0, 0, 1, ""))
+        val err6 = new ClassicFancyError(1, 0, 0, new RigidCaret(1), "").merge(new ClassicFancyError(0, 0, 0, new RigidCaret(1), ""))
         err6.isTrivialError shouldBe false
         err6.asParseError shouldBe a [FancyError]
     }
@@ -127,7 +128,7 @@ class DefuncErrorTests extends ParsleyTest {
         err.asParseError shouldBe a [TrivialError]
     }
     it should "support fancy errors as not trivial" in {
-        val err = new ClassicFancyError(0, 0, 0, 1, "").withHints(EmptyHints)
+        val err = new ClassicFancyError(0, 0, 0, new RigidCaret(1), "").withHints(EmptyHints)
         err.isTrivialError shouldBe false
         err.asParseError shouldBe a [FancyError]
     }
@@ -142,7 +143,7 @@ class DefuncErrorTests extends ParsleyTest {
         err.asParseError shouldBe a [TrivialError]
     }
     it should "support fancy errors as not trivial" in {
-        val err = new ClassicFancyError(0, 0, 0, 1, "").withReason("")
+        val err = new ClassicFancyError(0, 0, 0, new RigidCaret(1), "").withReason("")
         err.isTrivialError shouldBe false
         err.asParseError shouldBe a [FancyError]
     }
@@ -157,7 +158,7 @@ class DefuncErrorTests extends ParsleyTest {
         err.asParseError shouldBe a [TrivialError]
     }
     it should "support fancy errors as not trivial" in {
-        val err = new ClassicFancyError(0, 0, 0, 1, "").label("", 0)
+        val err = new ClassicFancyError(0, 0, 0, new RigidCaret(1), "").label("", 0)
         err.isTrivialError shouldBe false
         err.asParseError shouldBe a [FancyError]
     }
@@ -182,7 +183,7 @@ class DefuncErrorTests extends ParsleyTest {
         errOut.offset shouldBe 10
     }
     it should "work for fancy errors too" in {
-        val err = new ClassicFancyError(0, 0, 0, 1, "").amend(10, 10, 10)
+        val err = new ClassicFancyError(0, 0, 0, new RigidCaret(1), "").amend(10, 10, 10)
         val errOut = err.asParseError
         errOut.col shouldBe 10
         errOut.line shouldBe 10
@@ -198,7 +199,7 @@ class DefuncErrorTests extends ParsleyTest {
         errOut.offset shouldBe 0
     }
     it should "work for fancy errors too" in {
-        val err = new ClassicFancyError(0, 0, 0, 1, "").entrench.amend(10, 10, 10)
+        val err = new ClassicFancyError(0, 0, 0, new RigidCaret(1), "").entrench.amend(10, 10, 10)
         val errOut = err.asParseError
         err.entrenched shouldBe true
         errOut.col shouldBe 0
@@ -216,7 +217,7 @@ class DefuncErrorTests extends ParsleyTest {
         err2.offset shouldBe 10
     }
     it should "work for fancy errors too" in {
-        val err = new ClassicFancyError(0, 0, 0, 1, "").entrench
+        val err = new ClassicFancyError(0, 0, 0, new RigidCaret(1), "").entrench
         require(err.entrenched)
         err.dislodge.entrenched shouldBe false
         val err2 = err.dislodge.amend(10, 10, 10).asParseError