cjheath/treetop — pull request #4 by teleological (2013-05-24 04:22:10+00:00)
Title: Single label sequence

The current metagrammar parser forbits a sequence with only a single labeled element, as noted by @jbrains in issue 4 of nathansobo's branch of treetop. Digging in, it looked like this is because labels are only supported in sequences, and a sequence is distinguished by the presence of at least two expressions. This patch distinguishes a sequence consisting of a single expression with a mandatory label.