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
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
use super::*;
pub trait Strategy<I: Clone, O> {
fn recover<D: Debugger, P: Parser<I, O>>(
&self,
recovered_errors: Vec<Located<I, P::Error>>,
fatal_error: Located<I, P::Error>,
parser: P,
debugger: &mut D,
stream: &mut StreamOf<I, P::Error>,
) -> PResult<I, O, P::Error>;
}
#[derive(Copy, Clone)]
pub struct SkipThenRetryUntil<I, const N: usize>(pub [I; N]);
impl<I: Clone + PartialEq, O, const N: usize> Strategy<I, O> for SkipThenRetryUntil<I, N> {
fn recover<D: Debugger, P: Parser<I, O>>(
&self,
a_errors: Vec<Located<I, P::Error>>,
a_err: Located<I, P::Error>,
parser: P,
debugger: &mut D,
stream: &mut StreamOf<I, P::Error>,
) -> PResult<I, O, P::Error> {
loop {
if !stream.attempt(|stream| if stream.next().2.map_or(true, |tok| self.0.contains(&tok)) {
(false, false)
} else {
(true, true)
}) {
break (a_errors, Err(a_err));
}
#[allow(deprecated)]
let (mut errors, res) = debugger.invoke(&parser, stream);
if let Ok(out) = res {
errors.push(a_err);
break (errors, Ok(out));
}
}
}
}
pub fn skip_then_retry_until<I, const N: usize>(until: [I; N]) -> SkipThenRetryUntil<I, N> {
SkipThenRetryUntil(until)
}
#[derive(Copy, Clone)]
pub struct NestedDelimiters<I, F, const N: usize>(pub I, pub I, pub [(I, I); N], pub F);
impl<I: Clone + PartialEq, O, F: Fn() -> O, const N: usize> Strategy<I, O> for NestedDelimiters<I, F, N> {
fn recover<D: Debugger, P: Parser<I, O>>(
&self,
mut a_errors: Vec<Located<I, P::Error>>,
a_err: Located<I, P::Error>,
_parser: P,
_debugger: &mut D,
stream: &mut StreamOf<I, P::Error>,
) -> PResult<I, O, P::Error> {
let mut balance = 0;
let mut balance_others = [0; N];
let mut starts = Vec::new();
let mut error = None;
let recovered = loop {
if match stream.next() {
(_, span, Some(t)) if t == self.0 => { balance += 1; starts.push(span); true },
(_, _, Some(t)) if t == self.1 => { balance -= 1; starts.pop(); true },
(at, span, Some(t)) => {
for i in 0..N {
if t == self.2[i].0 {
balance_others[i] += 1;
} else if t == self.2[i].1 {
balance_others[i] -= 1;
if balance_others[i] < 0 && balance == 1 {
error.get_or_insert_with(|| Located::at(at, P::Error::unclosed_delimiter(starts.pop().unwrap(), self.0.clone(), span.clone(), self.1.clone(), Some(t.clone()))));
}
}
}
false
},
(at, span, None) => {
if balance > 0 && balance == 1 {
error.get_or_insert_with(|| match starts.pop() {
Some(start) => Located::at(at, P::Error::unclosed_delimiter(start, self.0.clone(), span, self.1.clone(), None)),
None => Located::at(at, P::Error::expected_input_found(span, Some(self.1.clone()), None)),
});
}
break false
},
} {
if balance == 0 {
break true;
} else if balance < 0 {
break false;
}
} else if balance == 0 {
break false;
}
};
if let Some(e) = error { a_errors.push(e); }
if recovered {
if a_errors.last().map_or(true, |e| a_err.at < e.at) {
a_errors.push(a_err);
}
(a_errors, Ok(((self.3)(), None)))
} else {
(a_errors, Err(a_err))
}
}
}
pub fn nested_delimiters<I: PartialEq, F, const N: usize>(start: I, end: I, others: [(I, I); N], fallback: F) -> NestedDelimiters<I, F, N> {
assert!(start != end, "Start and end delimiters cannot be the same when using `NestedDelimiters`, consider using `Delimiters` instead");
NestedDelimiters(start, end, others, fallback)
}
#[derive(Copy, Clone)]
pub struct Recovery<A, S>(pub(crate) A, pub(crate) S);
impl<I: Clone, O, A: Parser<I, O, Error = E>, S: Strategy<I, O>, E: Error<I>> Parser<I, O> for Recovery<A, S> {
type Error = E;
fn parse_inner<D: Debugger>(&self, debugger: &mut D, stream: &mut StreamOf<I, E>) -> PResult<I, O, E> {
match stream.try_parse(|stream| { #[allow(deprecated)] debugger.invoke(&self.0, stream) }) {
(a_errors, Ok(a_out)) => (a_errors, Ok(a_out)),
(a_errors, Err(a_err)) => self.1.recover(a_errors, a_err, &self.0, debugger, stream),
}
}
fn parse_inner_verbose(&self, d: &mut Verbose, s: &mut StreamOf<I, E>) -> PResult<I, O, E> { #[allow(deprecated)] self.parse_inner(d, s) }
fn parse_inner_silent(&self, d: &mut Silent, s: &mut StreamOf<I, E>) -> PResult<I, O, E> { #[allow(deprecated)] self.parse_inner(d, s) }
}