From 42cd185a7c28ef3ed8071e1c9a8fcc03b14f51ea Mon Sep 17 00:00:00 2001
From: drbaggy <js5@sanger.ac.uk>
Date: Tue, 16 Feb 2021 12:45:26 +0000
Subject: one-liner down to 112 characters! 104 bytes of usefulness! by not
 checking bits we assume to be correct in regexp

---
 challenge-100/james-smith/perl/ch-1.pl | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/challenge-100/james-smith/perl/ch-1.pl b/challenge-100/james-smith/perl/ch-1.pl
index 4d83710a33..b682620f73 100644
--- a/challenge-100/james-smith/perl/ch-1.pl
+++ b/challenge-100/james-smith/perl/ch-1.pl
@@ -33,12 +33,15 @@ is( fun_time( '12:00 pm' ), '12:00' );
 done_testing();
 
 ## 72 chars ############################################################
-#00000000111111111122222222223333333333444444444455555555556
-#23456789012345678901234567890123456789012345678901234567890
 
 ## Just split so slightly more readable and fits on 60 char lines
 ## Not nasty hack - we pop rather than shift as it saves 2 bytes!
-sub ft{pop=~s{(\d+):(\d+)\s*(\wm|)}{sprintf'%02d:%02d%s',
+## We assume that the minute portion will be two digits after the
+## ":" then we don't need to check it....
+
+## 112 bytes total - 104 inside the curly braces..
+
+sub ft{pop=~s{(\d+)(:..)\s*(.m|)}{sprintf'%02d%s%s',
 ($1%12||(12*!$3))+12*('pm'eq$3),$2,$3?'':$1<12?'am':'pm'}re}
 
 ## This is more readable version with notes...
@@ -48,18 +51,21 @@ sub fun_time {
     ## in our golfdom....
     s{
         ## Split into 3 parts, $1 - hours, $2 - minutes & $3 - am/pm
-      (\d+) : (\d+) \s* ( \wm | )
+      (\d+) (:..) \s* ( .m | )
         ## We assume all strings are valid - so we don't have to anchor
         ## at both ends or worry what the 12hr clock sufficies are
-        ## am/pm & \wm is shorter than [ap]m
+        ## am/pm and .m is shorter than [ap]m
+        ##
+        ## We assume that the time will always have a : followed
+        ## 2 digits...
         ##
-        ## Note if we right (\wm)? the 3rd capture variable $3 is
-        ## sometimes undefined - better is to use ([ap]m|) which
+        ## Note if we right (.m)? the 3rd capture variable $3 is
+        ## sometimes undefined - better is to use (.m|) which
         ## matches the same way but $3 is now an empty string not
         ## undefined when we have a 24 hour clock time
     }
     {
-      sprintf '%02d:%02d%s',
+      sprintf '%02d%s%s',
         ( $1 % 12 || ( 12 * ! $3 ) ) + 12 * ( 'pm' eq $3 ),
           ## Get hour modulo 12..
           ## From 24hr to 12hr clock we need to convert 00:?? to 12:??
-- 
cgit