pub fn environment_name(begin_or_end: &SyntaxNode) -> Option<String>Expand description
The environment name of a BEGIN or END node — the text of its NAME_GROUP
child, braces dropped.
Mirrors Begin::name on the BEGIN side, including its fallback to the bare
head control word for an environment-alias delimiter (issue #109). END nodes
keep the NAME_GROUP-only reading, so an alias closer stays nameless.