logos-codegen 0.14.1

Create ridiculously fast Lexers
Documentation 
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

use regex_syntax::hir::ClassBytesRange;
use regex_syntax::hir::ClassUnicodeRange;
use regex_syntax::utf8::Utf8Range;

use std::cmp::{Ord, Ordering};

#[derive(Clone, Copy, PartialEq, Eq, Hash)]
pub struct Range {
    pub start: u8,
    pub end: u8,
}

impl Range {
    pub fn as_byte(&self) -> Option<u8> {
        if self.is_byte() {
            Some(self.start)
        } else {
            None
        }
    }

    pub fn is_byte(&self) -> bool {
        self.start == self.end
    }
}

impl From<u8> for Range {
    fn from(byte: u8) -> Range {
        Range {
            start: byte,
            end: byte,
        }
    }
}

impl From<&u8> for Range {
    fn from(byte: &u8) -> Range {
        Range::from(*byte)
    }
}

impl Iterator for Range {
    type Item = u8;

    fn next(&mut self) -> Option<u8> {
        match self.start.cmp(&self.end) {
            std::cmp::Ordering::Less => {
                let res = self.start;
                self.start += 1;

                Some(res)
            }
            std::cmp::Ordering::Equal => {
                let res = self.start;

                // Necessary so that range 0xFF-0xFF doesn't loop forever
                self.start = 0xFF;
                self.end = 0x00;

                Some(res)
            }
            std::cmp::Ordering::Greater => None,
        }
    }
}

impl PartialOrd for Range {
    fn partial_cmp(&self, other: &Range) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}

impl Ord for Range {
    fn cmp(&self, other: &Self) -> Ordering {
        self.start.cmp(&other.start)
    }
}

impl From<Utf8Range> for Range {
    fn from(r: Utf8Range) -> Range {
        Range {
            start: r.start,
            end: r.end,
        }
    }
}

impl From<ClassUnicodeRange> for Range {
    fn from(r: ClassUnicodeRange) -> Range {
        let start = r.start() as u32;
        let end = r.end() as u32;

        if start >= 128 || end >= 128 && end != 0x0010FFFF {
            panic!("Casting non-ascii ClassUnicodeRange to Range")
        }

        Range {
            start: start as u8,
            end: end as u8,
        }
    }
}

impl From<ClassBytesRange> for Range {
    fn from(r: ClassBytesRange) -> Range {
        Range {
            start: r.start(),
            end: r.end(),
        }
    }
}

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

    #[test]
    fn range_iter_one() {
        let byte = Range::from(b'!');
        let collected = byte.take(1000).collect::<Vec<_>>();

        assert_eq!(b"!", &collected[..]);
    }

    #[test]
    fn range_iter_few() {
        let byte = Range {
            start: b'a',
            end: b'd',
        };
        let collected = byte.take(1000).collect::<Vec<_>>();

        assert_eq!(b"abcd", &collected[..]);
    }

    #[test]
    fn range_iter_bounds() {
        let byte = Range::from(0xFA..=0xFF);

        let collected = byte.take(1000).collect::<Vec<_>>();

        assert_eq!(b"\xFA\xFB\xFC\xFD\xFE\xFF", &collected[..]);
    }
}