generalized the move syntax regexes to arbritary board sizes

druid

@@ -1,4 +1,4 @@
-#!perl6
+use v6;
 
 # Given a string (assumed to contain no newlines), replaces a section of that
 # string, starting from $column, with the contents of $new_section. When
@@ -339,8 +339,20 @@ my $h_piece = '
 /-----/
 ';
 
-my $sarsen_move = /^ <[a..h]><[1..8]> $/;
-my $lintel_move = /^ <[a..h]><[1..8]> '-' <[a..h]><[1..8]> $/;
+# This didn't come out at all the way I wanted it to. I thought I'd use
+# assertions to check for the board limits, but that didn't work; I wanted
+# to declare the letter, number and coords things as regexes, but that didn't
+# work; I thought I'd call the regexes in the variables from the regexes in
+# $sarsen_move and $lintel_move, but that didn't work. Finally I had to
+# settle for the following: creating strings and eval'ing them.
+my $max_l = chr(ord('a') + $board_size - 1);
+my $col_letter = "<[a..$max_l]>";
+my $row_number = '[' ~ (1..$board_size).join('|') ~ ']';
+my $coords = $col_letter ~ $row_number;
+
+# Note that the dollar sign has to be backwhacked.
+my $sarsen_move = eval("/^ $coords \$/");
+my $lintel_move = eval("/^ $coords '-' $coords \$/");
 
 # A three-dimensional array. Each item is a layer in on the board, starting
 # from the ground. The number of elements in this array always corresponds to