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litrs 0.2.3

Parse and inspect Rust literals (i.e. tokens in the Rust programming language representing fixed values). Particularly useful for proc macros, but can also be used outside of a proc-macro context.
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use std::fmt;

use crate::{ParseError, err::{perr, ParseErrorKind::*}};


/// A bool literal: `true` or `false`. Also see [the reference][ref].
///
/// [ref]: https://doc.rust-lang.org/reference/tokens.html#boolean-literals
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum BoolLit {
    False,
    True,
}

impl BoolLit {
    /// Parses the input as a bool literal. Returns an error if the input is
    /// invalid or represents a different kind of literal.
    pub fn parse(s: &str) -> Result<Self, ParseError> {
        match s {
            "false" => Ok(Self::False),
            "true" => Ok(Self::True),
            _ => Err(perr(None, InvalidLiteral)),
        }
    }

    /// Returns the actual Boolean value of this literal.
    pub fn value(self) -> bool {
        match self {
            Self::False => false,
            Self::True => true,
        }
    }

    /// Returns the literal as string.
    pub fn as_str(&self) -> &'static str {
        match self {
            Self::False => "false",
            Self::True => "true",
        }
    }
}

impl fmt::Display for BoolLit {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.pad(self.as_str())
    }
}


#[cfg(test)]
mod tests;