rocket_codegen 0.3.17

use {ROUTE_STRUCT_PREFIX, CATCH_STRUCT_PREFIX};
use utils::{sep_by_tok, ParserExt, IdentExt};

use syntax::source_map::Span;
use syntax::tokenstream::TokenTree;
use syntax::ast::{Path, Expr};
use syntax::ext::base::{DummyResult, ExtCtxt, MacResult, MacEager};
use syntax::parse::token::Token;
use syntax::ptr::P;

pub fn prefix_paths(prefix: &str, paths: &mut Vec<Path>) {
    for p in paths {
        let last = p.segments.len() - 1;
        let last_seg = &mut p.segments[last];
        last_seg.ident = last_seg.ident.prepend(prefix);
    }
}

pub fn prefixing_vec_macro<F>(prefix: &str,
                              mut to_expr: F,
                              ecx: &mut ExtCtxt,
                              sp: Span,
                              args: &[TokenTree])
                              -> Box<MacResult + 'static>
    where F: FnMut(&ExtCtxt, Path) -> P<Expr>
{
    let mut parser = ecx.new_parser_from_tts(args);
    match parser.parse_paths() {
        Ok(mut paths) => {
            // Prefix each path terminator and build up the P<Expr> for each path.
            prefix_paths(prefix, &mut paths);
            let path_exprs: Vec<P<Expr>> = paths.into_iter()
                .map(|path| to_expr(ecx, path))
                .collect();

            // Now put them all in one vector and return the thing.
            let path_list = sep_by_tok(ecx, &path_exprs, Token::Comma);
            let output = quote_expr!(ecx, vec![$path_list]).into_inner();
            MacEager::expr(P(output))
        }
        Err(mut e) => {
            e.emit();
            DummyResult::expr(sp)
        }
    }
}

#[rustfmt_skip]
pub fn routes(ecx: &mut ExtCtxt, sp: Span, args: &[TokenTree])
        -> Box<MacResult + 'static> {
    prefixing_vec_macro(ROUTE_STRUCT_PREFIX, |ecx, path| {
        quote_expr!(ecx, ::rocket::Route::from(&$path))
    }, ecx, sp, args)
}

#[rustfmt_skip]
pub fn catchers(ecx: &mut ExtCtxt, sp: Span, args: &[TokenTree])
        -> Box<MacResult + 'static> {
    prefixing_vec_macro(CATCH_STRUCT_PREFIX, |ecx, path| {
        quote_expr!(ecx, rocket::Catcher::from(&$path))
    }, ecx, sp, args)
}

#[rustfmt_skip]
pub fn errors(ecx: &mut ExtCtxt, sp: Span, args: &[TokenTree])
        -> Box<MacResult + 'static> {
    ecx.struct_span_warn(sp, "use of deprecated Rocket macro `errors` \
                              (deprecated since v0.3.15)")
        .help("the `errors` macro was replaced by the `catchers` macro: \
               `catchers![..]`")
        .emit();
    catchers(ecx, sp, args)
}