Macro syn::braced

macro_rules! braced {
    ($content:ident in $cursor:expr) => { ... };
}

Parse a set of curly braces and expose their content to subsequent parsers.

Example

#[macro_use]
extern crate syn;
use syn::{token, Ident, Type};
use syn::parse::{Parse, ParseStream, Result};
use syn::punctuated::Punctuated;

// Parse a simplified struct syntax like:
//
//     struct S {
//         a: A,
//         b: B,
//     }
struct Struct {
    struct_token: Token![struct],
    ident: Ident,
    brace_token: token::Brace,
    fields: Punctuated<Field, Token![,]>,
}

struct Field {
    name: Ident,
    colon_token: Token![:],
    ty: Type,
}

impl Parse for Struct {
    fn parse(input: ParseStream) -> Result<Self> {
        let content;
        Ok(Struct {
            struct_token: input.parse()?,
            ident: input.parse()?,
            brace_token: braced!(content in input),
            fields: content.parse_terminated(Field::parse)?,
        })
    }
}

impl Parse for Field {
    fn parse(input: ParseStream) -> Result<Self> {
        Ok(Field {
            name: input.parse()?,
            colon_token: input.parse()?,
            ty: input.parse()?,
        })
    }
}