From 1d8fadd4308c5640b528145f8d89d065659b8d43 Mon Sep 17 00:00:00 2001
From: Som Snytt <som.snytt@gmail.com>
Date: Wed, 3 Jan 2024 18:45:52 -0800
Subject: [PATCH 1/2] Note changes in unicode escapes and case companion

---
 _overviews/FAQ/index.md                       |  8 +++++
 .../incompat-other-changes.md                 | 29 ++++++++++++++++++-
 .../scala3-migration/incompat-syntactic.md    | 11 +++++++
 .../scala3-migration/incompatibility-table.md |  1 +
 4 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/_overviews/FAQ/index.md b/_overviews/FAQ/index.md
index 96c5edd43..bfa999acc 100644
--- a/_overviews/FAQ/index.md
+++ b/_overviews/FAQ/index.md
@@ -139,6 +139,14 @@ REPL, but won't work in typical Scala 3 application code.
 For an alternative way to detect the Scala 3 version, see
 [this gist](https://gist.github.com/romanowski/de14691cab7340134e197419bc48919a).
 
+### I want to use Scala 3 but now a bunch of stuff just broke in my project. What's up with that?
+
+There is a [guide for migration](https://docs.scala-lang.org/scala3/guides/migration/compatibility-intro.html)
+that includes a [table of incompatibilities](https://docs.scala-lang.org/scala3/guides/migration/incompatibility-table.html).
+Incompatibilities are largely due to dropping old features and introducing new ones,
+rather than subtle changes in existing features.
+The migration guide provides strategies for either migrating to new syntax or maintaining cross-compatibility.
+
 ### Why is my (abstract or overridden) `val` null?
 
 <!-- this is left over from a previous version of the FAQ.
diff --git a/_overviews/scala3-migration/incompat-other-changes.md b/_overviews/scala3-migration/incompat-other-changes.md
index 90c04abab..4223411b4 100644
--- a/_overviews/scala3-migration/incompat-other-changes.md
+++ b/_overviews/scala3-migration/incompat-other-changes.md
@@ -166,6 +166,33 @@ fooCtr.tupled((2, false))
 ~~~
 {% endtab %}
 {% endtabs %}
+
+To assist migration, the compiler will insert the call to `apply` as needed:
+{% tabs scala-3-companion_3 %}
+{% tab 'Scala 3 Only' %}
+~~~ scala
+case class C(i: Int)
+List(42).map(C)
+case class D(i: Int, j: Int)
+List(42->27).map(D)
+~~~
+{% endtab %}
+{% endtabs %}
+
+In Scala 2.13.13, this behavior is enabled under `-Xsource:3cross`.
+That is, case companions that do not extend `Function` can be used as if they did,
+or equivalently, as though `apply` were inserted. However, since Scala 2 does not
+adapt `apply` for the tupled case, `tupled` is supported directly.
+{% tabs scala-3-companion_4 %}
+{% tab 'Scala 2 Only' %}
+~~~ scala
+case class C(i: Int); object C
+List(42).map(C)
+case class D(i: Int, j: Int); object D
+List(42->27).map(D.tupled)
+~~~
+{% endtab %}
+{% endtabs %}
 ## Explicit Call to `unapply`
 
 In Scala, case classes have an auto-generated extractor method, called `unapply` in their companion object.
@@ -325,4 +352,4 @@ In such case, we can use a wrapper class around `Foo`:
 
 -def g(foos: Seq[Foo[_]]): Unit
 +def g(foos: Seq[FooWrapper[_]]): Unit
-{% endhighlight %}
\ No newline at end of file
+{% endhighlight %}
diff --git a/_overviews/scala3-migration/incompat-syntactic.md b/_overviews/scala3-migration/incompat-syntactic.md
index 7ce3b2110..2ce3d6a7a 100644
--- a/_overviews/scala3-migration/incompat-syntactic.md
+++ b/_overviews/scala3-migration/incompat-syntactic.md
@@ -23,6 +23,7 @@ It is worth noting that most of the changes can be automatically handled during
 |[Wrong indentation](#wrong-indentation)||||
 |[`_` as a type parameter](#_-as-a-type-parameter)||||
 |[`+` and `-` as type parameters](#-and---as-type-parameters)||||
+|[Unicode escapes](incompat-syntactic.html#unicode-escapes)||||
 
 ## Restricted Keywords
 
@@ -237,3 +238,13 @@ The solution is to choose another valid identifier, for instance `T`.
 
 However, `+` and `-` still are valid type identifiers in general.
 You can write `type +`.
+
+## Unicode escapes
+
+Unicode escapes of the form `\u0061` are no longer natively supported in any position by the compiler.
+
+Instead, they processed like other escapes in string literals.
+This means, in particular, that they are not processed in "triple-quoted" strings or by the `raw` interpolator.
+
+In Scala 2, a deprecation is issued, but under `-Xsource:3cross`, the behavior is the same as Scala 3.
+
diff --git a/_overviews/scala3-migration/incompatibility-table.md b/_overviews/scala3-migration/incompatibility-table.md
index 8148eb7db..1493ff38c 100644
--- a/_overviews/scala3-migration/incompatibility-table.md
+++ b/_overviews/scala3-migration/incompatibility-table.md
@@ -42,6 +42,7 @@ Some of the old syntax is not supported anymore.
 |[Wrong indentation](incompat-syntactic.html#wrong-indentation)||||
 |[`_` as a type parameter](incompat-syntactic.html#_-as-a-type-parameter)||||
 |[`+` and `-` as type parameters](incompat-syntactic.html#-and---as-type-parameters)||||
+|[Unicode escapes](incompat-syntactic.html#unicode-escapes)||||
 
 ### Dropped Features
 

From e523d81988a4bfeed28172e66d3d35384743c710 Mon Sep 17 00:00:00 2001
From: Som Snytt <som.snytt@gmail.com>
Date: Wed, 3 Jan 2024 19:06:45 -0800
Subject: [PATCH 2/2] Repair virtus links

---
 _sips/sips/scala-cli.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/_sips/sips/scala-cli.md b/_sips/sips/scala-cli.md
index 2a3ba1577..d65f4c8c2 100644
--- a/_sips/sips/scala-cli.md
+++ b/_sips/sips/scala-cli.md
@@ -132,7 +132,7 @@ Last section of this proposal is the list of options that each sub-command MUST
  
 
 
-Scala CLI can also be configured with ["using directives"](https://scala-cli.virtuslab.org/docs/guides/using-directives) - a comment-based configuration syntax that should be placed at the top of Scala files. This allows for self-containing examples within one file since most of the configuration can be provided either from the command line or via using directives (command line has precedence). This is a game changer for use cases like scripting, reproduction, or within the academic scope.
+Scala CLI can also be configured with ["using directives"](https://scala-cli.virtuslab.org/docs/reference/directives#using-directives) - a comment-based configuration syntax that should be placed at the top of Scala files. This allows for self-containing examples within one file since most of the configuration can be provided either from the command line or via using directives (command line has precedence). This is a game changer for use cases like scripting, reproduction, or within the academic scope.
 
 We have described the motivation, syntax and implementation basis in the [dedicated pre-SIP](https://contributors.scala-lang.org/t/pre-sip-using-directives/5700). Currently, we recommend to write using directives as comments, so making them part of the language specification is not necessary at this stage. Moreover, the new `scala` command could ignore using directives in the initial version, however we strongly suggest to include comment-based using directives from the start. 
 
@@ -149,7 +149,7 @@ Adopting Scala CLI as the new `scala` command, as is, will change some of the be
 
 ### Other concerns
 
-Scala CLI brings [using directives](https://scala-cli.virtuslab.org/docs/guides/using-directives) and  [conventions to mark the test files](https://scala-cli.virtuslab.org/docs/commands/test#test-sources). We suggest to accept both accepted as a part of this SIP but we are ready to open dedicated SIPs for both (we have opened a [pre-SIP for using directives](https://contributors.scala-lang.org/t/pre-sip-using-directives/5700/15))
+Scala CLI brings [using directives](https://scala-cli.virtuslab.org/docs/reference/directives#using-directives) and  [conventions to mark the test files](https://scala-cli.virtuslab.org/docs/commands/test#test-sources). We suggest to accept both accepted as a part of this SIP but we are ready to open dedicated SIPs for both (we have opened a [pre-SIP for using directives](https://contributors.scala-lang.org/t/pre-sip-using-directives/5700/15))
 
 Scala CLI is an ambitious project and may seem hard to maintain in the long-run.