Merge pull request #253 from AleAndForCode/develop

Fix filter impl in Stream combinators #252
scalawithcats · Dec 20, 2024 · 4b2b7be · 4b2b7be
2 parents dd0f9ca + 28bd636
commit 4b2b7be
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Showing 2 changed files with 5 additions and 4 deletions.
diff --git a/src/pages/appendices/acknowledgements.md b/src/pages/appendices/acknowledgements.md
@@ -11,6 +11,7 @@ The members of ScalaBridge London and attendees at various training courses acte
 Thanks for the members of the PLT research group who inspired me directly back in the day, and continue to provide inspiration from afar.
 Finally, thanks to the following who sponsored my work or contributed with corrections and suggestions:
 
+Aleksandr Andreev,
 Charles Adetiloye,
 Johanna Odersky,
 Lunfu Zhong,

diff --git a/src/pages/codata/structural.md b/src/pages/codata/structural.md
@@ -318,7 +318,7 @@ trait Stream[A] {
 
       def tail: Stream[A] = {
         def loop(stream: Stream[A]): Stream[A] =
-          if pred(stream.head) then stream.tail
+          if pred(stream.head) then stream.tail.filter(pred)
           else loop(stream.tail)
 
         loop(self)
@@ -369,7 +369,7 @@ trait Stream[A] {
 
       def tail: Stream[A] = {
         def loop(stream: Stream[A]): Stream[A] =
-          if pred(stream.head) then stream.tail
+          if pred(stream.head) then stream.tail.filter(pred)
           else loop(stream.tail)
 
         loop(self)
@@ -456,7 +456,7 @@ trait Stream[A] {
 
       def tail: Stream[A] = {
         def loop(stream: Stream[A]): Stream[A] =
-          if pred(stream.head) then stream.tail
+          if pred(stream.head) then stream.tail.filter(pred)
           else loop(stream.tail)
 
         loop(self)
@@ -546,7 +546,7 @@ def filter(pred: A => Boolean): Stream[A] = {
 
     def tail: Stream[A] = {
       def loop(stream: Stream[A]): Stream[A] =
-        if pred(stream.head) then stream.tail
+        if pred(stream.head) then stream.tail.filter(pred)
         else loop(stream.tail)
 
       loop(self)