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

use crate::{
	not_parser::{
		NotParserError,
		NotParserRequirement,
	},
	Parser,
};
use std::marker::PhantomData;

#[derive(Debug)]
pub struct NotParser<'a, P>
where
	P: Parser<'a>,
{
	requirement: P,
	_a: PhantomData<&'a ()>,
}

impl<'a, P> NotParser<'a, P>
where
	P: Parser<'a>,
{
	pub fn new(requirement: P) -> Self
	{
		Self {
			requirement,
			_a: PhantomData,
		}
	}
}

impl<'a, P> Parser<'a> for NotParser<'a, P>
where
	P: Parser<'a>,
{
	type Error = NotParserError<'a, P>;
	type Output = P::Error;
	type Requirement = NotParserRequirement<'a, P>;
	type RequirementContext = ();

	fn parse(&self, src: &'a str, pos: &mut usize) -> Result<Self::Output, Self::Error>
	{
		let from = *pos;
		match self.requirement.parse(src, pos)
		{
			Ok(res) =>
			{
				*pos = from;
				Err(NotParserError::new(from, self.requirement(None), res))
			}
			Err(err) => Ok(err),
		}
	}

	fn requirement(&self, _: Option<&Self::RequirementContext>) -> Self::Requirement
	{
		NotParserRequirement::new(self.requirement.requirement(None))
	}
}