Method push_or_add_alternation

regex/regex-syntax/src/ast/parse.rs:669–681

Pushes or adds the given branch of an alternation to the parser's internal stack of state.

(&self, concat: ast::Concat)

    /// Pushes or adds the given branch of an alternation to the parser's
    /// internal stack of state.
    fn push_or_add_alternation(&self, concat: ast::Concat) {
        use self::GroupState::*;

        let mut stack = self.parser().stack_group.borrow_mut();
        if let Some(&mut Alternation(ref mut alts)) = stack.last_mut() {
            alts.asts.push(concat.into_ast());
            return;
        }
        stack.push(Alternation(ast::Alternation {
            span: Span::new(concat.span.start, self.pos()),
            asts: vec![concat.into_ast()],
        }));
    }

    /// Parse and push a group AST (and its parent concatenation) on to the
    /// parser's internal stack. Return a fresh concatenation corresponding