pgn_reader/
visitor.rs

1use shakmaty::{san::SanPlus, Outcome};
2
3use crate::types::{Nag, RawComment, RawHeader, Skip};
4
5/// Consumes games from a reader.
6///
7/// ![Flow](https://github.com/niklasf/rust-pgn-reader/blob/master/docs/visitor.png?raw=true)
8pub trait Visitor {
9    /// Value produced by the visitor after reading a game.
10    type Result;
11
12    /// Called at the start of the game.
13    fn begin_game(&mut self) {}
14
15    /// Called directly before reading game headers.
16    fn begin_headers(&mut self) {}
17    /// Called when parsing a game header like `[White "Deep Blue"]`.
18    fn header(&mut self, _key: &[u8], _value: RawHeader<'_>) {}
19    /// Called after reading the headers of a game. May skip quickly over
20    /// the following move text directly to
21    /// [`end_game()`](trait.Visitor.html#tymethod.end_game).
22    fn end_headers(&mut self) -> Skip {
23        Skip(false)
24    }
25
26    /// Called for each move, like `Nf3+`.
27    fn san(&mut self, _san_plus: SanPlus) {}
28    /// Called for each numeric annotation glyph like `!?` or `$7`.
29    fn nag(&mut self, _nag: Nag) {}
30    /// Called for each `{ comment }`.
31    fn comment(&mut self, _comment: RawComment<'_>) {}
32    /// Called for each `(`. May skip over the following variation directly
33    /// to [`end_variation()`](trait.Visitor.html#method.end_variation) (or to
34    /// [`end_game()`](trait.Visitor.html#tymethod.end_game) if no matching `)`
35    /// follows before the end of the game.
36    fn begin_variation(&mut self) -> Skip {
37        Skip(false)
38    }
39    /// Called for each `)`. It is *not* guaranteed that there was a
40    /// matching `(`.
41    fn end_variation(&mut self) {}
42    /// Called for each game termination, like `*` or `1-0`.
43    fn outcome(&mut self, _outcome: Option<Outcome>) {}
44
45    /// Called after parsing a game. Can produce a custom result.
46    fn end_game(&mut self) -> Self::Result;
47}
48
49pub(crate) struct SkipVisitor;
50
51impl Visitor for SkipVisitor {
52    type Result = ();
53
54    fn end_headers(&mut self) -> Skip {
55        Skip(true)
56    }
57    fn begin_variation(&mut self) -> Skip {
58        Skip(true)
59    }
60    fn end_game(&mut self) {}
61}
pgn_reader/visitor.rs

pgn_reader/
visitor.rs
