Diffstat (limited to 'src/walk/protocols.rs')
| -rw-r--r-- | src/walk/protocols.rs | 43 |
1 files changed, 0 insertions, 43 deletions
diff --git a/src/walk/protocols.rs b/src/walk/protocols.rs index 39e5faa..e69de29 100644 --- a/src/walk/protocols.rs +++ b/src/walk/protocols.rs @@ -1,43 +0,0 @@ -pub mod hint { - use crate::protocol::{Implementer, Protocol}; - - /// Protocol for giving a hint to a walker. - /// - /// This protocol is implemented by walkers. - /// - /// A hint is for a particular protocol `P`. - pub struct Hint<P: Meta>(P); - - /// Meta information for the hint. - /// - /// This gives the visitor more information to work from when selecting a hint. - pub trait Meta: Protocol { - /// Information known by the walker. - /// - /// This should be information easy to get without changing the state of the walker - /// in a irreversable way. - type Known<'a, 'ctx: 'a>; - - /// Extra information the visitor can give to the walker about what it is expecting. - type Hint<'a, 'ctx: 'a>; - } - - /// Object implementing the [`Hint`] protocol. - pub trait Object<'ctx, P: Meta> { - /// Hint to the walker to use the `P` protocol. - /// - /// This should only be called once per [`RequestHint`]. - fn hint( - &mut self, - visitor: &mut dyn Implementer<'ctx>, - hint: P::Hint<'_, 'ctx>, - ) -> Result<(), ()>; - - /// Ask the walker for information about it's support of the protocol. - fn known(&mut self, hint: &P::Hint<'_, 'ctx>) -> Result<P::Known<'_, 'ctx>, ()>; - } - - impl<P: Meta> Protocol for Hint<P> { - type Object<'a, 'ctx: 'a> = &'a mut dyn Object<'ctx, P>; - } -} |