diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs index b80551c99727..517fd9421ec6 100644 --- a/src/libsyntax/ext/expand.rs +++ b/src/libsyntax/ext/expand.rs @@ -1580,7 +1580,7 @@ pub fn expand_type(t: P, fld: &mut MacroExpander) -> P { &fld.cx.parse_sess.span_diagnostic, "type_macros", t.span, - "type macros are experimental (see tracking issue: 27336)"); + "type macros are experimental (see issue: #27336)"); t } } diff --git a/src/test/compile-fail/type-macros-fail.rs b/src/test/compile-fail/type-macros-fail.rs new file mode 100644 index 000000000000..8e8f21519bc5 --- /dev/null +++ b/src/test/compile-fail/type-macros-fail.rs @@ -0,0 +1,21 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +macro_rules! Id { + { $T:tt } => $T +} + +struct Foo { + x: Id!(T) +} + +fn main() { + let foo = Foo { x: i32 }; +} diff --git a/src/test/run-pass/type-macros-hlist.rs b/src/test/run-pass/type-macros-hlist.rs new file mode 100644 index 000000000000..7c7392894d97 --- /dev/null +++ b/src/test/run-pass/type-macros-hlist.rs @@ -0,0 +1,86 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#![feature(type_macros)] + +use std::ops::*; + +#[derive(Copy, Clone, Debug, Eq, Ord, PartialEq, PartialOrd)] +struct Nil; // empty HList +#[derive(Copy, Clone, Debug, Eq, Ord, PartialEq, PartialOrd)] +struct Cons(H, T); // cons cell of HList + +// trait to classify valid HLists +trait HList {} +impl HList for Nil {} +impl HList for Cons {} + +// term-level macro for HLists +macro_rules! hlist { + {} => { Nil }; + { $head:expr } => { Cons($head, Nil) }; + { $head:expr, $($tail:expr),* } => { Cons($head, hlist!($($tail),*)) }; +} + +// type-level macro for HLists +macro_rules! HList { + {} => { Nil }; + { $head:ty } => { Cons<$head, Nil> }; + { $head:ty, $($tail:ty),* } => { Cons<$head, HList!($($tail),*)> }; +} + +// nil case for HList append +impl Add for Nil { + type Output = Ys; + + fn add(self, rhs: Ys) -> Ys { + rhs + } +} + +// cons case for HList append +impl Add for Cons where + Xs: Add, +{ + type Output = Cons; + + fn add(self, rhs: Ys) -> Cons { + Cons(self.0, self.1 + rhs) + } +} + +// type macro Expr allows us to expand the + operator appropriately +macro_rules! Expr { + { ( $($LHS:tt)+ ) } => { Expr!($($LHS)+) }; + { HList ! [ $($LHS:tt)* ] + $($RHS:tt)+ } => { + >::Output + }; + { $LHS:tt + $($RHS:tt)+ } => { >::Output }; + { $LHS:ty } => { $LHS }; +} + +// test demonstrating term level `xs + ys` and type level `Expr!(Xs + Ys)` +fn main() { + fn aux(xs: Xs, ys: Ys) -> Expr!(Xs + Ys) + where Xs: Add { + xs + ys + } + + let xs: HList![&str, bool, Vec] = hlist!["foo", false, vec![]]; + let ys: HList![u64, [u8; 3], ()] = hlist![0, [0, 1, 2], ()]; + + // demonstrate recursive expansion of Expr! + let zs: Expr!((HList![&str] + HList![bool] + HList![Vec]) + + (HList![u64] + HList![[u8; 3], ()]) + + HList![]) + = aux(xs, ys); + assert_eq!(zs, hlist!["foo", false, vec![], 0, [0, 1, 2], ()]) +} + diff --git a/src/test/run-pass/type-macros-simple.rs b/src/test/run-pass/type-macros-simple.rs new file mode 100644 index 000000000000..22dfd507f7e2 --- /dev/null +++ b/src/test/run-pass/type-macros-simple.rs @@ -0,0 +1,19 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#![feature(type_macros)] + +macro_rules! Tuple { + { $A:ty,$B:ty } => { ($A, $B) } +} + +fn main() { + let x: Tuple!(i32, i32) = (1, 2); +}