Pop the last state from the parser's internal stack, if it exists, and add the given concatenation to it. There either must be no state or a single alternation item on the stack. Any other scenario produces an error. This assumes that the parser has advanced to the end.
(&self, mut concat: ast::Concat)
| 789 | /// |
| 790 | /// This assumes that the parser has advanced to the end. |
| 791 | fn pop_group_end(&self, mut concat: ast::Concat) -> Result<Ast> { |
| 792 | concat.span.end = self.pos(); |
| 793 | let mut stack = self.parser().stack_group.borrow_mut(); |
| 794 | let ast = match stack.pop() { |
| 795 | None => Ok(concat.into_ast()), |
| 796 | Some(GroupState::Alternation(mut alt)) => { |
| 797 | alt.span.end = self.pos(); |
| 798 | alt.asts.push(concat.into_ast()); |
| 799 | Ok(Ast::Alternation(alt)) |
| 800 | } |
| 801 | Some(GroupState::Group { group, .. }) => { |
| 802 | return Err(self.error( |
| 803 | group.span, |
| 804 | ast::ErrorKind::GroupUnclosed, |
| 805 | )); |
| 806 | } |
| 807 | }; |
| 808 | // If we try to pop again, there should be nothing. |
| 809 | match stack.pop() { |
| 810 | None => ast, |
| 811 | Some(GroupState::Alternation(_)) => { |
| 812 | // This unreachable is unfortunate. This case can't happen |
| 813 | // because the only way we can be here is if there were two |
| 814 | // `GroupState::Alternation`s adjacent in the parser's stack, |
| 815 | // which we guarantee to never happen because we never push a |
| 816 | // `GroupState::Alternation` if one is already at the top of |
| 817 | // the stack. |
| 818 | unreachable!() |
| 819 | } |
| 820 | Some(GroupState::Group { group, .. }) => { |
| 821 | Err(self.error(group.span, ast::ErrorKind::GroupUnclosed)) |
| 822 | } |
| 823 | } |
| 824 | } |
| 825 | |
| 826 | /// Parse the opening of a character class and push the current class |
| 827 | /// parsing context onto the parser's stack. This assumes that the parser |
no test coverage detected