utils/parser/
error.rs

1use crate::parser::then::Then2;
2use crate::parser::{ParseResult, Parser};
3use std::error::Error;
4use std::fmt::{Display, Formatter};
5
6/// Error type returned by [`Parser::parse`].
7#[non_exhaustive]
8#[derive(Debug, Copy, Clone, PartialEq, Eq)]
9pub enum ParseError {
10    /// Expected $type.
11    Expected(&'static str),
12    /// Expected $literal.
13    ExpectedLiteral(&'static str),
14    /// Expected $byte.
15    ExpectedByte(u8),
16    /// Expected $min - $max.
17    ExpectedByteRange(u8, u8),
18    /// Expected at least $n matches.
19    ExpectedMatches(usize),
20    /// Expected $n items or less.
21    ExpectedLessItems(usize),
22    /// Expected number <= $num.
23    NumberTooLarge(i128),
24    /// Expected number >= $num.
25    NumberTooSmall(i128),
26    /// Number out of range.
27    ///
28    /// Used as a fallback if min/max bound doesn't fit in an [`i128`] (for example, [`u128::MAX`]).
29    NumberOutOfRange(),
30    /// Custom error returned by [`Parser::map_res`] & [`Parser::error_msg`].
31    Custom(&'static str),
32}
33
34impl ParseError {
35    #[inline]
36    pub(super) fn too_large(max: impl TryInto<i128>) -> Self {
37        if let Ok(max) = max.try_into() {
38            Self::NumberTooLarge(max)
39        } else {
40            Self::NumberOutOfRange()
41        }
42    }
43
44    #[inline]
45    pub(super) fn too_small(min: impl TryInto<i128>) -> Self {
46        if let Ok(min) = min.try_into() {
47            Self::NumberTooSmall(min)
48        } else {
49            Self::NumberOutOfRange()
50        }
51    }
52}
53
54impl Display for ParseError {
55    #[cold]
56    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
57        match *self {
58            ParseError::Expected(x) => write!(f, "expected {x}"),
59            ParseError::ExpectedLiteral(x) => write!(f, "expected {x:?}"),
60            ParseError::ExpectedByte(x) => write!(f, "expected {:?}", x.escape_ascii().to_string()),
61            ParseError::ExpectedByteRange(min, max) => {
62                write!(
63                    f,
64                    "expected {:?}-{:?}",
65                    min.escape_ascii().to_string(),
66                    max.escape_ascii().to_string(),
67                )
68            }
69            ParseError::ExpectedMatches(x) => write!(f, "expected at least {x} match"),
70            ParseError::ExpectedLessItems(x) => write!(f, "expected {x} items or less"),
71            ParseError::NumberTooLarge(x) => write!(f, "expected number <= {x}"),
72            ParseError::NumberTooSmall(x) => write!(f, "expected number >= {x}"),
73            ParseError::NumberOutOfRange() => write!(f, "number out of range"),
74            ParseError::Custom(x) => f.write_str(x),
75        }
76    }
77}
78
79impl Error for ParseError {}
80
81#[derive(Copy, Clone)]
82pub struct WithErrorMsg<P> {
83    pub(super) parser: P,
84    pub(super) message: &'static str,
85}
86impl<P: Parser> Parser for WithErrorMsg<P> {
87    type Output<'i> = P::Output<'i>;
88    type Then<T: Parser> = Then2<Self, T>;
89
90    #[inline]
91    fn parse<'i>(&self, input: &'i [u8]) -> ParseResult<'i, Self::Output<'i>> {
92        match self.parser.parse(input) {
93            Ok(v) => Ok(v),
94            Err((_, pos)) => Err((ParseError::Custom(self.message), pos)),
95        }
96    }
97}
utils/parser/error.rs

utils/parser/
error.rs
