Merge pull request #643 from holli-holzer/master

Better wording, now enforcing the alphabet

2 files changed, 9 insertions, 4 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 2273b4f199..8c53908732 100644
--- a/challenge-026/markus-holzer/perl6/ch-2.p6
+++ b/challenge-026/markus-holzer/perl6/ch-2.p6
@@ -1,3 +1,5 @@
+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 }
@@ -15,11 +17,11 @@ sub mean-angle( *@α ) returns Real
     );
 
     ρ > 0
-        ?? ρ         # We always want positive values
+        ?? ρ         # We always want a positive value
         !! ρ + 2 * π # When it isn't, we add 360°
 }
 
-ok( mean-angle( 10°, 10°, 10° )         =~= 10°,  "The mean of 3 times alpha is alpha" );
+ok( mean-angle( 10°, 10°, 10° )         =~= 10°,  "The mean of equal angles is the angle" );
 ok( mean-angle( 10°, 20°, 30° )         =~= 20°,  "All angles in one quadrant" );
 ok( mean-angle( 355°, 5°, 15° )         =~= 5°,   "Angles in multiple quadrants" );
 ok( mean-angle( 90°, 180°, 270°, 360° ) =~= 270°, "Angle is not negative" );