Solution to task 2

1 files changed, 76 insertions, 0 deletions

diff --git a/challenge-239/jo-37/perl/ch-2.pl b/challenge-239/jo-37/perl/ch-2.pl
new file mode 100755
index 0000000000..22d7c4a317
--- /dev/null
+++ b/challenge-239/jo-37/perl/ch-2.pl
@@ -0,0 +1,76 @@
+#!/usr/bin/perl -s
+
+use v5.24;
+use Test2::V0;
+
+our ($tests, $examples, $verbose, $allowed);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless $allowed && @ARGV;
+usage: $0 [-examples] [-tests] [-verbose] [-allowed=A STR...]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+-verbose
+    print consistent strings instead of counting them
+
+-allowed=A
+    string of allowed characters
+
+STR...
+    list of strings
+
+EOS
+
+
+### Input and Output
+
+say $verbose ?
+    "@{[count_consistent($allowed, @ARGV)]}" :
+    scalar count_consistent($allowed, @ARGV);
+
+
+### Implementation
+
+sub count_consistent {
+    # there is no restriction to a character class in the task.  So
+    # allow meta characters, too:
+    my $allowed = quotemeta shift;
+    grep /^[$allowed]*$/, @_;
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        is scalar count_consistent(ab =>
+            qw(ad bd aaab baa badab)), 2, 'example 1';
+
+        is scalar count_consistent(abc =>
+            qw(a b c ab ac bc abc)), 7, 'example 2';
+
+        is scalar count_consistent(cad =>
+            qw(cc acd b ba bac bad ac d)), 4, 'example 3';
+
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        is [count_consistent('a-z].*[0-9' =>
+            qw(bc+1 .]0a a*z b-y))], [qw(.]0a a*z)], 'meta chars';
+
+        is count_consistent(abc => ''), 1, 'allow empty';
+	}
+
+    done_testing;
+    exit;
+}