expand out and comment on regex

1 files changed, 15 insertions, 0 deletions

diff --git a/challenge-110/james-smith/perl/ch-1.pl b/challenge-110/james-smith/perl/ch-1.pl
index f47ec05169..5435cde1b1 100644
--- a/challenge-110/james-smith/perl/ch-1.pl
+++ b/challenge-110/james-smith/perl/ch-1.pl
@@ -9,6 +9,21 @@ use Test::More;
 print grep { is_valid_phone_number($_) } <>;
 
 sub is_valid_phone_number {
+  return m{\A           # Start of line
+           \s*          # Some white-space ?
+           (?:          # Prefix - one of:
+             [+]\d+ |   #   +{digits}
+             00\d+  |   #   00{digits}
+             [(]\d+[)]  #   ({digits})
+           )
+           \s+          # Some white-space
+           \d+          # String of numbers
+           \s*          # Some white-space ?
+           \Z           # End of line
+          }x;
+}
+
+sub is_valid_phone_number_compact {
   return m{\A\s*(?:[+]\d+|00\d+|[(]\d+[)])\s+\d+\s*\Z};
 }