From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 21 Aug 2016 16:02:36 +0000 (+0100)
Subject: normalise: Support tie
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=appendix-a6.git;a=commitdiff_plain;h=7b75aa25275e551506f5cad2d54fe3548c65ef67;ds=sidebyside

normalise: Support tie
---

diff --git a/README.format b/README.format
index 6bbc5d6..1a75aae 100644
--- a/README.format
+++ b/README.format
@@ -60,6 +60,10 @@ Currently defined OPTNAMEs (default values shown)
  Election   seats=1     Number of seats to be filled.
  Election   _nodefault  For Debian A6, no default option
  Election   quorum=NUM  Quorum (default, none)
+ Election   _tie=C,C>D,D  Tie break: in tie of Cs vs Ds,
+                            take Cs to have more votes than Ds.
+                            also available with <, normalised to >
+                            normalised form has Cs and Ds sorted
 
  Candidate  Super=1:1   For Debian A6, RAT:IO, 
  Candidate  default     For Debian A6, Is the default option
diff --git a/normalise b/normalise
index c5a9077..0af8f19 100755
--- a/normalise
+++ b/normalise
@@ -14,9 +14,11 @@ use strict;
 
 our @options;
 our %candidates; # $candidates{CAND}{Desc}, {Opts}[]
+our %candref; # $candref{CAND} => msg of why needed
 our @ballots;
 
 my $candvoter_re = '\w+';
+my $cands_re = '\w+(?,\w+)*';
 my $opt_re = '\w+(?:=\S*)?';
 
 sub badinput ($) {
@@ -31,6 +33,17 @@ sub normalise_opts_list ($$) {
     foreach my $o (split /\s+/, $os) {
 	if ($o =~ m/^\w+$/) {
 	    push @o, $&;
+	} elsif ($o =~ s/^_[Tt]ie\=//) {
+	    $o =~ m/^($cands_re)([<>])($cands_re)$/
+		or badinput "bad value \`$_' for tie option";
+	    my ($l,$op,$r) = ($1,$2,$3);
+	    ($l,$op,$r) = ($r,'>',$l) if $op eq '<';
+	    $candref{$_} = "tie break spec" foreach $o =~ m/\w+/g;
+	    $l = join ',', sort split /\,/, $l;
+	    $r = join ',', sort split /\,/, $r;
+	    $l =~ m/\b$_\b/ and badinput "reflexive tie"
+		foreach split /\,/, $r;
+	    push @o, "$l$op$r";
 	} elsif ($o =~ m/^\w+\=\S+$/) {
 	    push @o, $&;
 	} elsif ($o !~ m/\S/) {
@@ -111,6 +124,11 @@ print STDERR Dumper($1,$2,$3);
 
 print "| @options\n" or die $!;
 
+foreach my $cand (sort keys %candref) {
+    badinput "missing candidate $cand (ref. by $candref{$cand}"
+	unless defined $candidates{$cand};
+}
+
 foreach my $cand (sort keys %candidates) {
     my $c = $candidates{$cand};
     $c->{Desc} //= $cand;