Scala 3 Braceless Syntax cont.

Author: fabianhjr

src/pages/applicatives/parallel.md

@@ -115,13 +115,11 @@ by defining a `FunctionK` that converts an `Option` to a `List`.
 ```scala mdoc:silent
 import cats.arrow.FunctionK
 
-object optionToList extends FunctionK[Option, List] {
+object optionToList extends FunctionK[Option, List]:
   def apply[A](fa: Option[A]): List[A] =
-    fa match {
+    fa match
       case None    => List.empty[A]
       case Some(a) => List(a)
-    }
-}
 ```
 ```scala mdoc
 optionToList(Some(1))

src/pages/case-studies/parser/applicative.md

@@ -19,12 +19,10 @@ Define an extension method `flatten`, and an instance of `Flattener` for a neste
 
 <div class="solution">
 ~~~ scala
-extension [A, B, C](in: ((A, B), C)) {
+extension [A, B, C](in: ((A, B), C))
   def flatten: (A, B, C) =
-    in match {
+    in match
       case ((a, b), c) => (a, b, c)
-    }
-}
 ~~~
 
 It's fairly straightforward to define this class, but we can't abstract over it in any way. If we want to define `flatten` for a tuple like `(a, (b, c))` we need to define a new extension method. Similarly if we want to flatten a tuple with four elements.

src/pages/case-studies/parser/intro.md

@@ -51,12 +51,11 @@ case class Parser(parse: String => ParseResult) {
       @tailrec
       def loop(result: String, remainder: String): ParseResult = {
         val result1 = this.parse(remainder)
-        result1 match {
+        result1 match
           case _ if result1.failed =>
             ParseResult(result, remainder)
           case ParseResult(result1, remainder1) =>
             loop(result + result1, remainder1)
-        }
       }
       loop("", input)
     }
@@ -115,18 +114,18 @@ Checkout the `parser-initial-a` tag to see the complete code with `~` implemente
 def ~(next: Parser): Parser =
   Parser { input =>
     val result = this.parse(input)
-    result match {
+    result match
       case _ if result.failed =>
         result
       case ParseResult(parsed, remainder) =>
         val result1 = next.parse(remainder)
-        result1 match {
+        result1 match
           case _ if result1.failed =>
             ParseResult("", input)
           case ParseResult(parsed1, remainder1) =>
             ParseResult(parsed + parsed1, remainder1)
-        }
-    }
+        end match
+    end match
   }
 ~~~
 </div>

src/pages/case-studies/validation/check.md

@@ -240,14 +240,14 @@ import cats.syntax.semigroup.* // for |+|
 ```
 
 ```scala mdoc:silent
-sealed trait Check[E, A] {
+sealed trait Check[E, A]:
   import Check.*
 
   def and(that: Check[E, A]): Check[E, A] =
     And(this, that)
 
   def apply(a: A)(using s: Semigroup[E]): Either[E, A] =
-    this match {
+    this match
       case Pure(func) =>
         func(a)
 
@@ -258,9 +258,9 @@ sealed trait Check[E, A] {
           case (Right(_),  Left(e))   => e.asLeft
           case (Right(_), Right(_)) => a.asRight
         }
-    }
-}
-object Check {
+    end match
+
+object Check:
   final case class And[E, A](
     left: Check[E, A],
     right: Check[E, A]) extends Check[E, A]
@@ -270,7 +270,6 @@ object Check {
 
   def pure[E, A](f: A => Either[E, A]): Check[E, A] =
     Pure(f)
-}
 ```
 
 Let's see an example:
@@ -336,29 +335,27 @@ import cats.syntax.apply.*     // for mapN
 ```
 
 ```scala mdoc:silent
-sealed trait Check[E, A] {
+sealed trait Check[E, A]:
   import Check.*
 
   def and(that: Check[E, A]): Check[E, A] =
     And(this, that)
 
   def apply(a: A)(using s: Semigroup[E]): Validated[E, A] =
-    this match {
+    this match
       case Pure(func) =>
         func(a)
 
       case And(left, right) =>
         (left(a), right(a)).mapN((_, _) => a)
-    }
-}
-object Check {
+
+object Check:
   final case class And[E, A](
     left: Check[E, A],
     right: Check[E, A]) extends Check[E, A]
 
   final case class Pure[E, A](
     func: A => Validated[E, A]) extends Check[E, A]
-}
 ```
 </div>
 
@@ -381,7 +378,7 @@ import cats.data.Validated.*   // for Valid and Invalid
 ```
 
 ```scala mdoc:silent
-sealed trait Check[E, A] {
+sealed trait Check[E, A]:
   import Check.*
 
   def and(that: Check[E, A]): Check[E, A] =
@@ -391,7 +388,7 @@ sealed trait Check[E, A] {
     Or(this, that)
 
   def apply(a: A)(using s: Semigroup[E]): Validated[E, A] =
-    this match {
+    this match
       case Pure(func) =>
         func(a)
 
@@ -407,9 +404,9 @@ sealed trait Check[E, A] {
               case Invalid(e2) => Invalid(e1 |+| e2)
             }
         }
-    }
-}
-object Check {
+    end match
+
+object Check:
   final case class And[E, A](
     left: Check[E, A],
     right: Check[E, A]) extends Check[E, A]
@@ -420,7 +417,6 @@ object Check {
 
   final case class Pure[E, A](
     func: A => Validated[E, A]) extends Check[E, A]
-}
 ```
 </div>
 

src/pages/case-studies/validation/kleisli.md

@@ -177,7 +177,7 @@ import cats.syntax.semigroup.* // for |+|
 import cats.data.Validated
 import cats.data.Validated.{Valid, Invalid}
 
-sealed trait Predicate[E, A] {
+sealed trait Predicate[E, A]:
   import Predicate.*
 
   def and(that: Predicate[E, A]): Predicate[E, A] =
@@ -190,7 +190,7 @@ sealed trait Predicate[E, A] {
     (a: A) => this(a).toEither
 
   def apply(a: A)(using s: Semigroup[E]): Validated[E, A] =
-    this match {
+    this match
       case Pure(func) =>
         func(a)
 
@@ -206,10 +206,10 @@ sealed trait Predicate[E, A] {
               case Invalid(e2) => Invalid(e1 |+| e2)
             }
         }
-    }
-}
+    end match
+end Predicate
 
-object Predicate {
+object Predicate:
   final case class And[E, A](
     left: Predicate[E, A],
     right: Predicate[E, A]) extends Predicate[E, A]
@@ -226,7 +226,7 @@ object Predicate {
 
   def lift[E, A](error: E, func: A => Boolean): Predicate[E, A] =
     Pure(a => if(func(a)) Valid(a) else Invalid(error))
-}
+end Predicate
 ```
 
 Working around limitations of type inference