moxy-token 0.1.0

Rust token types/parsing/lexing
Documentation 
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mod error;
mod stream;

#[doc(inline)]
pub use error::*;

#[doc(inline)]
pub use stream::*;

/// Parse a source string into a typed AST node, returning `Result<T, ParseError>`.
///
/// The type can be given explicitly with `as T` or inferred from context.
///
/// # Example
/// ```
/// use moxy_token::*;
///
/// let token: Fn = parse!("fn").unwrap();
/// let token = parse!("fn" as Fn).unwrap();
/// ```
#[macro_export]
macro_rules! parse {
    ($src:tt as $ty:ty) => {{
        use ::std::str::FromStr;
        $crate::TokenStream::from_str(&$src.to_string())
            .map_err($crate::parser::ParseError::from)
            .and_then(|ts| ts.parse().parse::<$ty>())
    }};
    ($src:tt) => {{
        use ::std::str::FromStr;
        $crate::TokenStream::from_str(&$src.to_string())
            .map_err($crate::parser::ParseError::from)
            .and_then(|ts| ts.parse().parse())
    }};
}

pub trait Parse: Sized {
    fn parse(stream: &mut ParseStream) -> Result<Self, ParseError>;
}

pub trait Peek: Sized {
    fn peek(stream: &mut ParseStream) -> bool;
}

impl<T: Parse> Peek for T {
    fn peek(stream: &mut ParseStream) -> bool {
        Self::parse(stream).is_ok()
    }
}

impl<T: Parse> Parse for Option<T> {
    #[inline]
    fn parse(stream: &mut ParseStream) -> Result<Self, ParseError> {
        if stream.peek::<T>() {
            stream.parse().map(Some)
        } else {
            Ok(None)
        }
    }
}

impl<T: Parse> Parse for Vec<T> {
    fn parse(stream: &mut ParseStream) -> Result<Self, ParseError> {
        Ok(stream.parse_while::<T>())
    }
}

impl<T: Parse> Parse for Box<T> {
    fn parse(stream: &mut ParseStream) -> Result<Self, ParseError> {
        Ok(Self::new(stream.parse()?))
    }
}