Merge pull request #3074 from stuart-little/stuart-little_027

1st commit on 027

3 files changed, 42 insertions, 0 deletions

diff --git a/challenge-027/stuart-little/README b/challenge-027/stuart-little/README
new file mode 100644
index 0000000000..78439907de
--- /dev/null
+++ b/challenge-027/stuart-little/README
@@ -0,0 +1 @@
+Solutions by Stuart Little
diff --git a/challenge-027/stuart-little/raku/ch-1.p6 b/challenge-027/stuart-little/raku/ch-1.p6
new file mode 100755
index 0000000000..e511f70557
--- /dev/null
+++ b/challenge-027/stuart-little/raku/ch-1.p6
@@ -0,0 +1,15 @@
+#!/usr/bin/env perl6
+use v6;
+
+# run as <script> <eight space-separated coordinates: a b c d p q r s for points (a,b), (c,d), etc.>
+
+use Math::Matrix;
+
+sub intersect(($a,$b,$c,$d,$p,$q,$r,$s)) {
+    ($d-$b)*($r-$p) == ($c-$a)*($s-$q) && return "The lines have equal slope: no unique intersection.";
+    my $A = Math::Matrix.new([[$b-$d,$c-$a],[$q-$s,$r-$p]]);
+    my $v=Math::Matrix.new([[$b*$c-$a*$d],[$q*$r-$p*$s]]);
+    return $A.inverted.dot-product($v);
+}
+
+say intersect(@*ARGS[0..7])
diff --git a/challenge-027/stuart-little/raku/ch-2.p6 b/challenge-027/stuart-little/raku/ch-2.p6
new file mode 100755
index 0000000000..a994b643b5
--- /dev/null
+++ b/challenge-027/stuart-little/raku/ch-2.p6
@@ -0,0 +1,26 @@
+#!/usr/bin/env perl6
+use v6;
+
+# run as <script>
+# 
+# learned of STORE from
+# https://rosettacode.org/wiki/History_variables#Raku
+
+class HistVar {
+    has @!history;
+    has $!var handles <Str gist>;
+    method STORE($val) is rw {
+        $!var.defined && push @!history, $!var;
+	say ((@!history) ?? ("was: {@!history};  ") !! ""), "is now: {$val}";
+        $!var = $val;
+    }
+}
+
+my @x is HistVar.new;
+
+@x=1;
+@x=2;
+@x=3;
+@x=4;
+
+say "current: {@x}";