blob: 69e2c7daed5afaeb2d0bebae99f31487fa147acb (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
use crate::error::Result;
use crate::parser_tables_generated::Term;
/// This macro is pre-processed by the python grammar processor and generate
/// code out-side the current context.
#[macro_export]
macro_rules! grammar_extension {
( $($_:tt)* ) => {};
}
/// Aggregate a Value (= StackValue or ()) and a nonterminal/terminal as a stack
/// element. The term is currently used for replaying the parse table when
/// handling errors and non-optimized reduced actions with lookahead.
#[derive(Debug)]
pub struct TermValue<Value> {
pub term: Term,
pub value: Value,
}
/// The parser trait is an abstraction to define the primitive of an LR Parser
/// with variable lookahead which can be replayed.
pub trait ParserTrait<'alloc, Value> {
fn shift(&mut self, tv: TermValue<Value>) -> Result<'alloc, bool>;
fn shift_replayed(&mut self, state: usize);
fn unshift(&mut self);
fn rewind(&mut self, n: usize) {
for _ in 0..n {
self.unshift();
}
}
fn pop(&mut self) -> TermValue<Value>;
fn replay(&mut self, tv: TermValue<Value>);
fn epsilon(&mut self, state: usize);
fn top_state(&self) -> usize;
fn check_not_on_new_line(&mut self, peek: usize) -> Result<'alloc, bool>;
}
|
