Enforce alphabet

2 files changed, 6 insertions, 3 deletions

diff --git a/challenge-026/markus-holzer/perl6/ch-1.p6 b/challenge-026/markus-holzer/perl6/ch-1.p6
index 85f29cab2c..70e6ceeaeb 100644
--- a/challenge-026/markus-holzer/perl6/ch-1.p6
+++ b/challenge-026/markus-holzer/perl6/ch-1.p6
@@ -3,11 +3,14 @@ use Test;
 # In Raku, all operators are just multi - functions.
 # So we can easily define ourselves an infix left-associative element-of operator.
 # It will take an `Iterable` (`Seq`, `Array`, `List`) on its left side and a `Set` on the right side.
-# It returns a `Seq` of all elements of the left side that are present on the right side.
+# It returns a `Seq` of all elements of the left side that are present on the right side and that
+# are part of our alphabet
 
 multi sub infix:<\<∈>( Iterable $stones, Set $jewels ) returns Seq
 {
-    $stones.grep: * ∈ $jewels
+    # constant runs at BEGIN time, so this work gets only done once
+    constant \alphabet = ( 'a' .. 'z', 'A' .. 'Z' ).Set;
+    $stones.grep({ $_ ∈ alphabet && $_ ∈ $jewels });
 }
 
 # Now we could call that good, but in true Raku spirit we provide additional
diff --git a/challenge-026/markus-holzer/perl6/ch-2.p6 b/challenge-026/markus-holzer/perl6/ch-2.p6
index 8c53908732..68e4321c19 100644
--- a/challenge-026/markus-holzer/perl6/ch-2.p6
+++ b/challenge-026/markus-holzer/perl6/ch-2.p6
@@ -2,7 +2,7 @@ use Test;
 
 # Rakus trigonometry functions operate on radians. So we must convert degrees to radians.
 # That's simple enough using a new postfix operator and high school math.
-multi sub postfix:<°>( Numeric $degrees ) returns Real { $degrees * π / 180 }
+multi sub postfix:<°>( Numeric $degrees ) is looser(&prefix:<->) returns Real { $degrees * π / 180 }
 
 # This implements the "simple" version of the algorithm as described on Wikipedia.
 # There already is an implementation of the complex math version (that uses `i`)