litrs/bool/
mod.rs

1use std::fmt;
2
3use crate::{ParseError, err::{perr, ParseErrorKind::*}};
4
5
6/// A bool literal: `true` or `false`. Also see [the reference][ref].
7///
8/// [ref]: https://doc.rust-lang.org/reference/tokens.html#boolean-literals
9#[derive(Debug, Clone, Copy, PartialEq, Eq)]
10pub enum BoolLit {
11    False,
12    True,
13}
14
15impl BoolLit {
16    /// Parses the input as a bool literal. Returns an error if the input is
17    /// invalid or represents a different kind of literal.
18    pub fn parse(s: &str) -> Result<Self, ParseError> {
19        match s {
20            "false" => Ok(Self::False),
21            "true" => Ok(Self::True),
22            _ => Err(perr(None, InvalidLiteral)),
23        }
24    }
25
26    /// Returns the actual Boolean value of this literal.
27    pub fn value(self) -> bool {
28        match self {
29            Self::False => false,
30            Self::True => true,
31        }
32    }
33
34    /// Returns the literal as string.
35    pub fn as_str(&self) -> &'static str {
36        match self {
37            Self::False => "false",
38            Self::True => "true",
39        }
40    }
41}
42
43impl fmt::Display for BoolLit {
44    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
45        f.pad(self.as_str())
46    }
47}
48
49
50#[cfg(test)]
51mod tests;