1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Support for parsing unsupported, old syntaxes, for the purpose of reporting errors. Parsing of
12 //! these syntaxes is tested by compile-test/obsolete-syntax.rs.
14 //! Obsolete syntax that becomes too hard to parse can be removed.
16 pub use self::ObsoleteSyntax::*;
18 use ast::{Expr, ExprTup};
24 /// The specific types of unsupported syntax
25 #[derive(Copy, PartialEq, Eq, Hash)]
26 pub enum ObsoleteSyntax {
32 ObsoleteImportRenaming,
33 ObsoleteSubsliceMatch,
34 ObsoleteExternCrateRenaming,
40 pub trait ParserObsoleteMethods {
41 /// Reports an obsolete syntax non-fatal error.
42 fn obsolete(&mut self, sp: Span, kind: ObsoleteSyntax);
43 /// Reports an obsolete syntax non-fatal error, and returns
44 /// a placeholder expression
45 fn obsolete_expr(&mut self, sp: Span, kind: ObsoleteSyntax) -> P<Expr>;
51 fn is_obsolete_ident(&mut self, ident: &str) -> bool;
52 fn eat_obsolete_ident(&mut self, ident: &str) -> bool;
55 impl<'a> ParserObsoleteMethods for parser::Parser<'a> {
56 /// Reports an obsolete syntax non-fatal error.
57 fn obsolete(&mut self, sp: Span, kind: ObsoleteSyntax) {
58 let (kind_str, desc) = match kind {
61 "use unboxed closures instead",
65 "use a `move ||` expression instead",
67 ObsoleteOwnedType => (
68 "`~` notation for owned pointers",
69 "use `Box<T>` in `std::owned` instead"
71 ObsoleteOwnedExpr => (
72 "`~` notation for owned pointer allocation",
73 "use the `box` operator instead of `~`"
75 ObsoleteOwnedPattern => (
76 "`~` notation for owned pointer patterns",
77 "use the `box` operator instead of `~`"
79 ObsoleteOwnedVector => (
80 "`~[T]` is no longer a type",
81 "use the `Vec` type instead"
83 ObsoleteOwnedSelf => (
84 "`~self` is no longer supported",
85 "write `self: Box<Self>` instead"
87 ObsoleteImportRenaming => (
88 "`use foo = bar` syntax",
89 "write `use bar as foo` instead"
91 ObsoleteSubsliceMatch => (
92 "subslice match syntax",
93 "instead of `..xs`, write `xs..` in a pattern"
95 ObsoleteExternCrateRenaming => (
96 "`extern crate foo = bar` syntax",
97 "write `extern crate bar as foo` instead"
99 ObsoleteClosureType => (
100 "`|uint| -> bool` closure type syntax",
101 "use unboxed closures instead, no type annotation needed"
105 self.report(sp, kind, kind_str, desc);
108 /// Reports an obsolete syntax non-fatal error, and returns
109 /// a placeholder expression
110 fn obsolete_expr(&mut self, sp: Span, kind: ObsoleteSyntax) -> P<Expr> {
111 self.obsolete(sp, kind);
112 self.mk_expr(sp.lo, sp.hi, ExprTup(vec![]))
117 kind: ObsoleteSyntax,
121 format!("obsolete syntax: {}", kind_str)[]);
123 if !self.obsolete_set.contains(&kind) {
127 .note(format!("{}", desc)[]);
128 self.obsolete_set.insert(kind);
132 fn is_obsolete_ident(&mut self, ident: &str) -> bool {
134 token::Ident(sid, _) => {
135 token::get_ident(sid) == ident
141 fn eat_obsolete_ident(&mut self, ident: &str) -> bool {
142 if self.is_obsolete_ident(ident) {