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 #[deriving(PartialEq, Eq, Hash)]
26 pub enum ObsoleteSyntax {
32 ObsoleteImportRenaming,
33 ObsoleteSubsliceMatch,
34 ObsoleteExternCrateRenaming,
37 pub trait ParserObsoleteMethods {
38 /// Reports an obsolete syntax non-fatal error.
39 fn obsolete(&mut self, sp: Span, kind: ObsoleteSyntax);
40 /// Reports an obsolete syntax non-fatal error, and returns
41 /// a placeholder expression
42 fn obsolete_expr(&mut self, sp: Span, kind: ObsoleteSyntax) -> P<Expr>;
48 fn is_obsolete_ident(&mut self, ident: &str) -> bool;
49 fn eat_obsolete_ident(&mut self, ident: &str) -> bool;
52 impl<'a> ParserObsoleteMethods for parser::Parser<'a> {
53 /// Reports an obsolete syntax non-fatal error.
54 fn obsolete(&mut self, sp: Span, kind: ObsoleteSyntax) {
55 let (kind_str, desc) = match kind {
56 ObsoleteOwnedType => (
57 "`~` notation for owned pointers",
58 "use `Box<T>` in `std::owned` instead"
60 ObsoleteOwnedExpr => (
61 "`~` notation for owned pointer allocation",
62 "use the `box` operator instead of `~`"
64 ObsoleteOwnedPattern => (
65 "`~` notation for owned pointer patterns",
66 "use the `box` operator instead of `~`"
68 ObsoleteOwnedVector => (
69 "`~[T]` is no longer a type",
70 "use the `Vec` type instead"
72 ObsoleteOwnedSelf => (
73 "`~self` is no longer supported",
74 "write `self: Box<Self>` instead"
76 ObsoleteImportRenaming => (
77 "`use foo = bar` syntax",
78 "write `use bar as foo` instead"
80 ObsoleteSubsliceMatch => (
81 "subslice match syntax",
82 "instead of `..xs`, write `xs..` in a pattern"
84 ObsoleteExternCrateRenaming => (
85 "`extern crate foo = bar` syntax",
86 "write `extern crate bar as foo` instead"
90 self.report(sp, kind, kind_str, desc);
93 /// Reports an obsolete syntax non-fatal error, and returns
94 /// a placeholder expression
95 fn obsolete_expr(&mut self, sp: Span, kind: ObsoleteSyntax) -> P<Expr> {
96 self.obsolete(sp, kind);
97 self.mk_expr(sp.lo, sp.hi, ExprTup(vec![]))
102 kind: ObsoleteSyntax,
106 format!("obsolete syntax: {}", kind_str).as_slice());
108 if !self.obsolete_set.contains(&kind) {
112 .note(format!("{}", desc).as_slice());
113 self.obsolete_set.insert(kind);
117 fn is_obsolete_ident(&mut self, ident: &str) -> bool {
119 token::Ident(sid, _) => {
120 token::get_ident(sid).equiv(&ident)
126 fn eat_obsolete_ident(&mut self, ident: &str) -> bool {
127 if self.is_obsolete_ident(ident) {