dora_parser/lexer/
position.rs

1use std::fmt::{Display, Error, Formatter};
2use std::result::Result;
3
4#[derive(PartialEq, Eq, Debug, Copy, Clone)]
5pub struct Position {
6    pub line: u32,
7    pub column: u32,
8}
9
10impl Position {
11    pub fn new(l: u32, c: u32) -> Position {
12        assert!(l >= 1);
13        assert!(c >= 1);
14
15        Position { line: l, column: c }
16    }
17}
18
19impl Display for Position {
20    fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
21        write!(f, "{}:{}", self.line, self.column)
22    }
23}
24
25#[derive(Copy, Clone, Debug)]
26pub struct Span {
27    start: Loc,
28    count: u32,
29}
30
31impl Span {
32    pub fn new(start: u32, count: u32) -> Span {
33        Span {
34            start: Loc::new(start),
35            count,
36        }
37    }
38
39    pub fn at(start: u32) -> Span {
40        Span {
41            start: Loc::new(start),
42            count: 0,
43        }
44    }
45
46    pub fn invalid() -> Span {
47        Span {
48            start: Loc::invalid(),
49            count: 0,
50        }
51    }
52
53    pub fn is_valid(&self) -> bool {
54        self.start.is_valid()
55    }
56
57    pub fn start(&self) -> u32 {
58        self.start.idx()
59    }
60
61    pub fn count(&self) -> u32 {
62        self.count
63    }
64
65    pub fn end(&self) -> u32 {
66        self.start.idx() + self.count
67    }
68}
69
70#[derive(Copy, Clone, Debug)]
71pub struct Loc(u32);
72
73impl Loc {
74    fn new(pos: u32) -> Loc {
75        assert!(pos < u32::max_value());
76        Loc(pos)
77    }
78
79    fn invalid() -> Loc {
80        Loc(u32::max_value())
81    }
82
83    fn is_valid(&self) -> bool {
84        self.0 != u32::max_value()
85    }
86
87    fn idx(&self) -> u32 {
88        assert!(self.is_valid());
89        self.0
90    }
91}
92
93#[test]
94fn test_new() {
95    let pos = Position::new(3, 1);
96
97    assert_eq!(pos.line, 3);
98    assert_eq!(pos.column, 1);
99
100    assert_eq!(&format!("{}", pos)[..], "3:1");
101}
dora_parser/lexer/position.rs

dora_parser/lexer/
position.rs
