From 7551356237bd76b784b7224f2845afb4ccb9cec7 Mon Sep 17 00:00:00 2001
From: Ruben Westerberg <drclaw@mac.com>
Date: Sun, 25 Aug 2019 08:46:12 +1000
Subject: Added ch-2.p6

Refactored ch-2.pl to use List::Util
Removed superfluous conditional blocks
---
 challenge-022/ruben-westerberg/README        |  8 ++----
 challenge-022/ruben-westerberg/perl5/ch-2.pl | 18 ++++--------
 challenge-022/ruben-westerberg/perl6/ch-2.p6 | 43 ++++++++++++++++++++++++++++
 3 files changed, 50 insertions(+), 19 deletions(-)
 create mode 100755 challenge-022/ruben-westerberg/perl6/ch-2.p6

diff --git a/challenge-022/ruben-westerberg/README b/challenge-022/ruben-westerberg/README
index 1f319161be..26a2690833 100644
--- a/challenge-022/ruben-westerberg/README
+++ b/challenge-022/ruben-westerberg/README
@@ -2,13 +2,9 @@ Solution by Ruben Westerberg
 
 ch-1.pl and ch-1.p6
 ===
-Run with a single argument. Argument is the number of terms to add in calculating Eulers number. If no argument is given, a default of 10 terms are used.
+Run the program to calculate the first ten sexy prime pairs
 
 ch-2.pl and ch-2.p6
 ===
-Run with a single argument. Argument is a URI which is normalized (no semantic changes). If no argument is given a test URI is used.
-- Normalizes scheme to lower case
-- Normalize % codes to upper case
-- decode unreserved % codes if present
-- encode any characters outside of reserved or unreserved codes.
+Run the program with a command line argument to demonstrate the LZW encoding. With no argument, a demonstration string is used
 
diff --git a/challenge-022/ruben-westerberg/perl5/ch-2.pl b/challenge-022/ruben-westerberg/perl5/ch-2.pl
index f0f4051395..98895fd8e7 100755
--- a/challenge-022/ruben-westerberg/perl5/ch-2.pl
+++ b/challenge-022/ruben-westerberg/perl5/ch-2.pl
@@ -1,6 +1,7 @@
 #!/usr/bin/env perl
 use strict;
 use warnings;
+use List::Util qw<uniq first>;
 use v5.26;
 
 # implement LZW 
@@ -23,26 +24,17 @@ print "Decoded: ",join("",@decoded),"\n";
 
 sub encode {
 	my ($dict,$in, $out)=@_;
-	@$dict= ((0..9),('A'..'Z'),('a'..'z'));
+	@$dict= uniq @$in;# ((0..9),('A'..'Z'),('a'..'z'));
 	push @$in, undef;
 	for (@$in) {
 		state $symbol="";
-		state $count= @$dict;
 		my $next=$_;#shift;
 		$symbol.=$next if defined $next;
 		state $prev="";
-		my $s=(grep {$symbol eq $_} @$dict)[0];
-		my $res;
-		if (defined $s and  $next) {
-			#found existing keep adding
-			$res=undef;
-		}
-		else {
-			#add new symbol
-			#$$dict{$symbol}=$count++;
+		my $s=first {$symbol eq $_} @$dict; 
+		unless ( $s and $next) {
 			push @$dict, $symbol;
-			$res=(grep {$prev eq $$dict[$_]} 0..@$dict-1)[0];
-			push @$out, $res;
+			push @$out, first {$prev eq $$dict[$_]} 0..@$dict-1;
 			$symbol=substr $symbol, -1;
 		}
 		$prev=$symbol;
diff --git a/challenge-022/ruben-westerberg/perl6/ch-2.p6 b/challenge-022/ruben-westerberg/perl6/ch-2.p6
new file mode 100755
index 0000000000..23c5e67daa
--- /dev/null
+++ b/challenge-022/ruben-westerberg/perl6/ch-2.p6
@@ -0,0 +1,43 @@
+#!/usr/bin/env perl6
+
+# implement LZW 
+my @input=comb "", @*ARGS[0]//"TOBEORNOTTOBEORTOBEORNOT";
+my @decoded;
+my @encoded;
+my @symbols;
+
+print "Input: ",join("",@input),"\n";
+
+encode(@symbols, @input ,@encoded);
+
+print "Encoded: ",join(",",@encoded),"\n";
+
+decode(@symbols,@encoded,@decoded);
+
+print "Decoded: ",join("",@decoded),"\n";
+
+
+sub encode (@dict, @in, @out) {
+	@dict= @in.unique; 	#Create initial dictionary
+	push @in, Any;		#Add end marker to input	
+	for @in {
+		state $symbol="";
+		my $next=$_;
+		$symbol~=$next if $next.defined;
+		state $prev="";
+		my $s=first {$symbol eq $_}, @dict;	#Search for existing
+		unless $s.defined and $next.defined {
+			push @dict, $symbol;
+			push @out, @dict.first: {$prev eq $_ },:k;
+			$symbol=substr $symbol, *-1;
+		}
+		$prev=$symbol;
+	}
+}
+
+
+sub decode(@dict, @in, @out) {
+	for @in {
+		push @out, @dict[$_];
+	}
+}
-- 
cgit