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(Copy, PartialEq, Eq, Hash)]
26 pub enum ObsoleteSyntax {
32 ObsoleteImportRenaming,
33 ObsoleteSubsliceMatch,
34 ObsoleteExternCrateRenaming,
39 pub trait ParserObsoleteMethods {
40 /// Reports an obsolete syntax non-fatal error.
41 fn obsolete(&mut self, sp: Span, kind: ObsoleteSyntax);
42 /// Reports an obsolete syntax non-fatal error, and returns
43 /// a placeholder expression
44 fn obsolete_expr(&mut self, sp: Span, kind: ObsoleteSyntax) -> P<Expr>;
50 fn is_obsolete_ident(&mut self, ident: &str) -> bool;
51 fn eat_obsolete_ident(&mut self, ident: &str) -> bool;
54 impl<'a> ParserObsoleteMethods for parser::Parser<'a> {
55 /// Reports an obsolete syntax non-fatal error.
56 fn obsolete(&mut self, sp: Span, kind: ObsoleteSyntax) {
57 let (kind_str, desc) = match kind {
60 "use unboxed closures instead",
64 "use a `move ||` expression instead",
66 ObsoleteOwnedType => (
67 "`~` notation for owned pointers",
68 "use `Box<T>` in `std::owned` instead"
70 ObsoleteOwnedExpr => (
71 "`~` notation for owned pointer allocation",
72 "use the `box` operator instead of `~`"
74 ObsoleteOwnedPattern => (
75 "`~` notation for owned pointer patterns",
76 "use the `box` operator instead of `~`"
78 ObsoleteOwnedVector => (
79 "`~[T]` is no longer a type",
80 "use the `Vec` type instead"
82 ObsoleteOwnedSelf => (
83 "`~self` is no longer supported",
84 "write `self: Box<Self>` instead"
86 ObsoleteImportRenaming => (
87 "`use foo = bar` syntax",
88 "write `use bar as foo` instead"
90 ObsoleteSubsliceMatch => (
91 "subslice match syntax",
92 "instead of `..xs`, write `xs..` in a pattern"
94 ObsoleteExternCrateRenaming => (
95 "`extern crate foo = bar` syntax",
96 "write `extern crate bar as foo` instead"
100 self.report(sp, kind, kind_str, desc);
103 /// Reports an obsolete syntax non-fatal error, and returns
104 /// a placeholder expression
105 fn obsolete_expr(&mut self, sp: Span, kind: ObsoleteSyntax) -> P<Expr> {
106 self.obsolete(sp, kind);
107 self.mk_expr(sp.lo, sp.hi, ExprTup(vec![]))
112 kind: ObsoleteSyntax,
116 format!("obsolete syntax: {}", kind_str)[]);
118 if !self.obsolete_set.contains(&kind) {
122 .note(format!("{}", desc)[]);
123 self.obsolete_set.insert(kind);
127 fn is_obsolete_ident(&mut self, ident: &str) -> bool {
129 token::Ident(sid, _) => {
130 token::get_ident(sid) == ident
136 fn eat_obsolete_ident(&mut self, ident: &str) -> bool {
137 if self.is_obsolete_ident(ident) {