Trait swc_common::comments::Comments

source · [−]
pub trait Comments {

Show 15 methods    fn add_leading(&self, pos: BytePos, cmt: Comment);
    fn add_leading_comments(&self, pos: BytePos, comments: Vec<Comment>);
    fn has_leading(&self, pos: BytePos) -> bool;
    fn move_leading(&self, from: BytePos, to: BytePos);
    fn take_leading(&self, pos: BytePos) -> Option<Vec<Comment>>;
    fn get_leading(&self, pos: BytePos) -> Option<Vec<Comment>>;
    fn add_trailing(&self, pos: BytePos, cmt: Comment);
    fn add_trailing_comments(&self, pos: BytePos, comments: Vec<Comment>);
    fn has_trailing(&self, pos: BytePos) -> bool;
    fn move_trailing(&self, from: BytePos, to: BytePos);
    fn take_trailing(&self, pos: BytePos) -> Option<Vec<Comment>>;
    fn get_trailing(&self, pos: BytePos) -> Option<Vec<Comment>>;
    fn add_pure_comment(&self, pos: BytePos);

    fn with_leading<F, Ret>(&self, pos: BytePos, f: F) -> Ret
    where
        Self: Sized,
        F: FnOnce(&[Comment]) -> Ret,
    { ... }
    fn with_trailing<F, Ret>(&self, pos: BytePos, f: F) -> Ret
    where
        Self: Sized,
        F: FnOnce(&[Comment]) -> Ret,
    { ... }

}
Expand description

Stores comment.

Implementation notes

Methods uses (&self) instead of (&mut self) for some reasons. Firstly, this is similar to the previous api. Secondly, typescript parser requires backtracking, which requires Clone. To avoid cloning large vectors, we must use Rc<RefCell>. We have two option. We may implement it in the parser or in the implementation. If we decide to go with first option, we should pass Comments to parser, and as a result we need another method to take comments back. If we decide to go with second way, we can just pass [&Comments] to the parser. Thirdly, (&self) allows multi-threaded use-cases such as swc itself.

We use Option instead of no-op Comments implementation to avoid allocation unless required.

Required Methods

Provided Methods

Implementations on Foreign Types

This implementation behaves like NoopComments if it’s None.

Implementors