Function syntex_syntax::ext::proc_macro_shim::build_block_emitter

pub fn build_block_emitter<'cx>(cx: &'cx mut ExtCtxt, sp: Span, output: TokenStream) -> Box<MacResult + 'cx>

Take a ExtCtxt, Span, and TokenStream, and produce a Macro Result that parses the TokenStream as a block and returns it as an Expr.