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
157
158
159
160
161
162
163

use std::{num::ParseIntError, str::FromStr};

use lazy_static::lazy_static;
use regex::Regex;

use crate::{parsers::regex::RegexParser, ParseContext, ParseIter, Reported};

/// A trivial ParseIter that presents exactly one match and holds a
/// pre-converted value.
///
/// Some parsers, like `u64`, do all the work of conversion as part of
/// confirming that a match is valid. Rather than do the work again during the
/// `convert` phase, the answer is stored in this iterator.
pub struct BasicParseIter<T> {
    pub(crate) end: usize,
    pub(crate) value: T,
}

impl<'parse, T> ParseIter<'parse> for BasicParseIter<T>
where
    T: Clone,
{
    type RawOutput = (T,);

    fn match_end(&self) -> usize {
        self.end
    }

    fn backtrack(&mut self, _context: &mut ParseContext<'parse>) -> Result<(), Reported> {
        Err(Reported)
    }

    fn convert(&self) -> (T,) {
        (self.value.clone(),)
    }
}

// --- Global regexes that are compiled on first use

macro_rules! regexes {
    ( $( $name:ident = $re:expr ; )* ) => {
        $(
            pub(crate) fn $name() -> &'static Regex {
                lazy_static! {
                    static ref RE: Regex = Regex::new($re).unwrap();
                }
                &RE
            }
        )*
    }
}

regexes! {
    uint_regex = r"\A[0-9]+";
    int_regex = r"\A[+-]?[0-9]+";
    bool_regex = r"true|false";
    uint_bin_regex = r"\A[01]+";
    int_bin_regex = r"\A[+-]?[01]+";
    uint_hex_regex = r"\A[0-9A-Fa-f]+";
    int_hex_regex = r"\A[+-]?[0-9A-Fa-f]+";
}

// --- Parsers that use FromStr

macro_rules! from_str_parse_impl {
        ( $( $ty:ident )+ , $re_name:ident) => {
            $(
                /// Parse a value of a primitive type (using its `FromStr`
                /// implementation in the Rust standard library).
                #[allow(non_upper_case_globals)]
                pub const $ty: RegexParser<$ty, <$ty as FromStr>::Err> =
                    RegexParser {
                        regex: $re_name,
                        parse_fn: <$ty as FromStr>::from_str,
                    };
            )+
        };
    }

from_str_parse_impl!(u8 u16 u32 u64 u128 usize, uint_regex);
from_str_parse_impl!(i8 i16 i32 i64 i128 isize, int_regex);
from_str_parse_impl!(bool, bool_regex);

// --- Parsers for `_bin` and `_hex` integers

macro_rules! from_str_radix_parsers {
    ( $( ( $ty:ident , $bin:ident , $hex:ident ) ),* ; $bin_re:ident, $hex_re:ident ) => {
        $(
            /// Parse an integer written in base 2, using the `from_str_radix`
            /// static method from the Rust standard library.
            #[allow(non_upper_case_globals)]
            pub const $bin: RegexParser<$ty, ParseIntError> = RegexParser {
                regex: $bin_re,
                parse_fn: |s| $ty::from_str_radix(s, 2),
            };

            /// Parse an integer written in base 16, using the `from_str_radix`
            /// static method from the Rust standard library.
            #[allow(non_upper_case_globals)]
            pub const $hex: RegexParser<$ty, ParseIntError> = RegexParser {
                regex: $hex_re,
                parse_fn: |s| $ty::from_str_radix(s, 16),
            };

        )*
    }
}

from_str_radix_parsers!(
    (u8, u8_bin, u8_hex),
    (u16, u16_bin, u16_hex),
    (u32, u32_bin, u32_hex),
    (u64, u64_bin, u64_hex),
    (u128, u128_bin, u128_hex),
    (usize, usize_bin, usize_hex);
    uint_bin_regex,
    uint_hex_regex
);

from_str_radix_parsers!(
    (i8, i8_bin, i8_hex),
    (i16, i16_bin, i16_hex),
    (i32, i32_bin, i32_hex),
    (i64, i64_bin, i64_hex),
    (i128, i128_bin, i128_hex),
    (isize, isize_bin, isize_hex);
    int_bin_regex,
    int_hex_regex
);

#[cfg(test)]
mod tests {
    use super::*;
    use crate::testing::*;

    #[test]
    fn test_parse_hex() {
        assert_no_parse(&i32_hex, "+");
        assert_no_parse(&i32_hex, "-");
        assert_no_parse(&i32_hex, "+ 4");
        assert_no_parse(&i32_hex, "+ 4");
        assert_parse_eq(&i32_hex, "7BCDEF01", 0x7bcdef01);
        assert_parse_eq(&i32_hex, "7fffffff", i32::MAX);
        assert_no_parse(&i32_hex, "80000000");
        assert_parse_eq(&i32_hex, "-80000000", i32::MIN);
        assert_no_parse(&i32_hex, "-80000001");

        let p = sequence(i32_hex, i32_hex);
        assert_no_parse(&p, "12");
        assert_no_parse(&p, "01230123ABCDABCD");
        assert_parse_eq(&p, "-1+1", (-1, 1));

        assert_no_parse(&u32_hex, "-1");
        assert_no_parse(&u32_hex, "+d3d32e2e");
        assert_parse_eq(&u32_hex, "ffffffff", u32::MAX);
        assert_parse_eq(&u32_hex, "ffffffff", u32::MAX);
        assert_parse_eq(
            &u32_hex,
            "0000000000000000000000000000000000000000000000000000000000000000ffffffff",
            u32::MAX,
        );
    }
}