ilex 0.6.0

quick and easy lexers for C-like languages
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

use ilex::fp::Fp64;
use ilex::rule::*;
use ilex::token;
use ilex::Lexeme;

#[ilex::spec]
struct Numbers {
  #[rule(",")]
  comma: Lexeme<Keyword>,

  #[named("binary number")]
  #[rule(Digital::new(2)
    .separator('_')
    .plus().minus()
    .point_limit(0..2)
    .exponent("2", Digits::new(2).plus().minus())
    .prefixes(["0b", "0B", "%"]))]
  bin: Lexeme<Digital>,

  #[named = "hexadecimal number"]
  #[rule(Digital::new(16)
    .separator('_')
    .plus().minus()
    .point_limit(0..2)
    .exponents(["p", "P"], Digits::new(10).plus().minus())
    .prefixes(["0x", "0X", "$"]))]
  hex: Lexeme<Digital>,

  #[named = "quaternary number"]
  #[rule(Digital::new(4)
    .separator('_')
    .plus().minus()
    .point_limit(0..2)
    .exponents(["p", "P"], Digits::new(10).plus().minus())
    .prefixes(["0q", "0Q"]))]
  qua: Lexeme<Digital>,

  #[named = "octal number"]
  #[rule(Digital::new(8)
    .separator('_')
    .plus().minus()
    .point_limit(0..2)
    .exponents(["p", "P"], Digits::new(10).plus().minus())
    .prefixes(["0o", "0O", "0"]))]
  oct: Lexeme<Digital>,

  #[named = "decimal number"]
  #[rule(Digital::new(10)
    .separator('_')
    .plus().minus()
    .point_limit(0..2)
    .exponents(["e", "E"], Digits::new(10).plus().minus())
    .exponent("^", Digits::new(16).plus().minus()))]
  dec: Lexeme<Digital>,
}

#[test]
fn numbers() {
  let lex = Numbers::get();
  let text = r#"
    0,
    -00,
    -0.0,
    123.456e78,
    9e9,
    -9e9,
    +9e+9,
    9e-9,
    -0777,
    0o777,
    %1210,
    0b0.0000000101,
    0o0.0024,
    0O1.01p01,
    0xfff.eep+10,
    $DEADBEEF,
    -0q0123.0123,
    3^a,
  "#;

  let ctx = ilex::Context::new();
  let _u = ctx.use_for_debugging_spans();
  let report = ctx.new_report();
  let tokens = ctx
    .new_file("test.file", text)
    .lex(lex.spec(), &report)
    .unwrap();
  eprintln!("stream: {tokens:#?}");

  let mut cursor = tokens.cursor();
  let numbers = cursor
    .delimited(lex.comma, |cursor| loop {
      let value = token::switch()
        .case(Lexeme::eof(), |_, _| Err(false))
        .cases([lex.dec, lex.bin, lex.oct, lex.hex, lex.qua], |num, _| {
          Ok(num.to_float::<Fp64>(.., &report).unwrap())
        })
        .take(cursor, &report);
      match value {
        None => {
          cursor.back_up(1);
          return Some(Fp64::nan());
        }
        Some(Err(false)) => return None,
        Some(Err(true)) => continue,
        Some(Ok(v)) => return Some(v),
      }
    })
    .map(|(v, _)| v)
    .collect::<Vec<_>>();
  cursor.expect_finished(&report);
  report.fatal_or(()).unwrap();

  assert_eq!(
    numbers,
    [
      "0",
      "-0",
      "-0",
      "123.456e78",
      "9e9",
      "-9e9",
      "9e9",
      "9e-9",
      "-511",
      "511",
      "4",
      "0.0048828125",
      "0.0048828125",
      "2.03125",
      "4194232",
      "3735928559",
      "-27.10546875",
      "3e10",
    ]
    .into_iter()
    .map(Fp64::new)
    .collect::<Vec<_>>()
  );
}