From f4f3d93f551953a75aecef48689cf599b60cd55e Mon Sep 17 00:00:00 2001
From: Jörg Sommrey <28217714+jo-37@users.noreply.github.com>
Date: Mon, 26 Apr 2021 14:10:12 +0200
Subject: Solution to task 1

---
 challenge-110/jo-37/perl/ch-1.pl | 97 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100755 challenge-110/jo-37/perl/ch-1.pl

diff --git a/challenge-110/jo-37/perl/ch-1.pl b/challenge-110/jo-37/perl/ch-1.pl
new file mode 100755
index 0000000000..431e48c1b2
--- /dev/null
+++ b/challenge-110/jo-37/perl/ch-1.pl
@@ -0,0 +1,97 @@
+#!/usr/bin/perl -s
+
+use v5.16;
+use Test2::V0;
+use experimental 'signatures';
+
+our ($tests, $examples);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV;
+usage: $0 [-examples] [-tests] [file ...]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+file ...
+    name of input file(s)
+
+EOS
+
+
+### Input and Output
+
+# perlvar states:
+#   passing "\*ARGV" as a parameter to a function that expects a
+#   filehandle may not cause your function to automatically read the
+#   contents of all the files in @ARGV.
+# It seems to work, though.
+say for phone_numbers(\*ARGV);
+
+
+### Implementation
+
+# Search the given filehandle for valid phone numbers according to the
+# specified number formats.
+# The specification is a bit vague, especially as the example
+# '+44 1148820341' does not match the respective format
+# '+nn  nnnnnnnnnn'.  Therefore some additional assumptions are made:
+# - a fixed international dialing prefix of '00'
+# - the country code has exactly 2 digits
+# - the national number has exactly 10 digits
+# - multiple numbers may appear on the same line
+# - a phone number starting with a digit must not follow a digit
+# - a phone number must not be followed by a digit
+# - the number of blanks between prefix and national number is variable
+sub phone_numbers ($fh) {
+    my @num;
+    while (<$fh>) {
+        push @num, /((?:\+\d{2}|\(\d{2}\)|(?<!\d)00\d{2}) +\d{10})(?!\d)/g;
+    }
+
+    @num;
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        open my $fh, '<', \<<EOS;
+            0044 1148820341
+             +44 1148820341
+              44-11-4882-0341
+            (44) 1148820341
+              00 1148820341
+EOS
+        is [phone_numbers($fh)],
+            ['0044 1148820341', '+44 1148820341', '(44) 1148820341'],
+            'example';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        open my $fh, '<', \<<EOS;
+            x0012 1234567890 0023 2345678901y   # valid pair
+            x0034 34567890120045 4567890123y    # forbidden adjacent digits
+            x+56  5678901234(67) 6789012345y    # valid pair
+            0111 1234567890                     # wrong prefix
+            +12  123456789                      # number too short
+            (12) 12345678901                    # number too long
+EOS
+        is [phone_numbers($fh)],
+            ['0012 1234567890', '0023 2345678901',
+            '+56  5678901234', '(67) 6789012345'],
+            'several multiple entries';
+	}
+
+    done_testing;
+    exit;
+}
-- 
cgit