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
use crate::ast::prelude::*;
#[test]
#[cfg(not(miri))]
fn ast_parse() {
rt::<ast::Lit>("true");
rt::<ast::Lit>("false");
rt::<ast::Lit>("'🔥'");
rt::<ast::Lit>("b'4'");
rt::<ast::Lit>("b\"bytes\"");
rt::<ast::Lit>("1.2");
rt::<ast::Lit>("42");
rt::<ast::Lit>("\"mary had a little lamb\"");
}
/// A literal value,
///
/// These are made available by parsing Rune. Custom literals for macros can be
/// constructed through [MacroContext::lit][crate::macros::MacroContext::lit].
///
/// # Examples
///
/// Constructing a literal value:
///
/// ```
/// use rune::ast;
/// use rune::macros;
///
/// macros::test(|cx| {
/// let lit = cx.lit("hello world")?;
/// assert!(matches!(lit, ast::Lit::Str(..)));
/// Ok(())
/// })?;
/// # Ok::<_, rune::support::Error>(())
/// ```
#[derive(Debug, TryClone, Clone, Copy, PartialEq, Eq, ToTokens, Spanned)]
#[try_clone(copy)]
#[non_exhaustive]
pub enum Lit {
/// A boolean literal
Bool(ast::LitBool),
/// A byte literal
Byte(ast::LitByte),
/// A string literal
Str(ast::LitStr),
/// A byte string literal
ByteStr(ast::LitByteStr),
/// A character literal
Char(ast::LitChar),
/// A number literal
Number(ast::LitNumber),
}
impl Lit {
/// Test if this is an immediate literal in an expression.
///
/// Here we only test for unambiguous literals which will not be caused by
/// a later stage as an expression is being parsed.
///
/// These include:
/// * Object literals that start with a path (handled in [ast::Expr::parse_with_meta_path]).
/// * Tuple literals that start with a path (handled in [ast::Expr::parse_open_paren]).
pub(crate) fn peek_in_expr(p: &mut Peeker<'_>) -> bool {
match p.nth(0) {
K![true] | K![false] => true,
K![byte] => true,
K![number] => true,
K![char] => true,
K![str] => true,
K![bytestr] => true,
_ => false,
}
}
}
impl Parse for Lit {
fn parse(p: &mut Parser<'_>) -> Result<Self> {
match p.nth(0)? {
K![true] | K![false] => return Ok(Lit::Bool(p.parse()?)),
K![byte(_)] => return Ok(Lit::Byte(p.parse()?)),
K![number(_)] => return Ok(Lit::Number(p.parse()?)),
K![char(_)] => return Ok(Lit::Char(p.parse()?)),
K![str(_)] => return Ok(Lit::Str(p.parse()?)),
K![bytestr(_)] => return Ok(Lit::ByteStr(p.parse()?)),
_ => (),
}
Err(compile::Error::expected(p.next()?, Expectation::Literal))
}
}