Newick tree format
AUTHOR
Lucien Grondin
See https://en.wikipedia.org/wiki/Newick_format.
use v6;
grammar Newick {
rule TOP { '(' <subtree>** 2..3 % \, ');' }
rule subtree { <species> | '(' <subtree>** 2 % \, ')' }
token species { <.ident>+ }
}
# vim: expandtab shiftwidth=4 ft=perl6