rust/src/libsyntax/parse/token.rs
Patrick Walton 2257e231a7 librustc: Eliminate the ref syntax for unboxed closure capture clauses
in favor of `move`.

This breaks code that used `move` as an identifier, because it is now a
keyword. Change such identifiers to not use the keyword `move`.
Additionally, this breaks code that was counting on by-value or
by-reference capture semantics for unboxed closures (behind the feature
gate). Change `ref |:|` to `|:|` and `|:|` to `move |:|`.

Part of RFC #63; part of issue #12831.

[breaking-change]
2014-09-26 09:03:19 -07:00

789 lines
24 KiB
Rust

// Copyright 2012-2013 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 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use ast;
use ast::{Ident, Name, Mrk};
use ext::mtwt;
use parse::token;
use ptr::P;
use util::interner::{RcStr, StrInterner};
use util::interner;
use serialize::{Decodable, Decoder, Encodable, Encoder};
use std::fmt;
use std::mem;
use std::path::BytesContainer;
use std::rc::Rc;
#[allow(non_camel_case_types)]
#[deriving(Clone, Encodable, Decodable, PartialEq, Eq, Hash, Show)]
pub enum BinOp {
PLUS,
MINUS,
STAR,
SLASH,
PERCENT,
CARET,
AND,
OR,
SHL,
SHR,
}
#[allow(non_camel_case_types)]
#[deriving(Clone, Encodable, Decodable, PartialEq, Eq, Hash, Show)]
pub enum Token {
/* Expression-operator symbols. */
EQ,
LT,
LE,
EQEQ,
NE,
GE,
GT,
ANDAND,
OROR,
NOT,
TILDE,
BINOP(BinOp),
BINOPEQ(BinOp),
/* Structural symbols */
AT,
DOT,
DOTDOT,
DOTDOTDOT,
COMMA,
SEMI,
COLON,
MOD_SEP,
RARROW,
LARROW,
FAT_ARROW,
LPAREN,
RPAREN,
LBRACKET,
RBRACKET,
LBRACE,
RBRACE,
POUND,
DOLLAR,
QUESTION,
/* Literals */
LIT_BYTE(Name),
LIT_CHAR(Name),
LIT_INTEGER(Name),
LIT_FLOAT(Name),
LIT_STR(Name),
LIT_STR_RAW(Name, uint), /* raw str delimited by n hash symbols */
LIT_BINARY(Name),
LIT_BINARY_RAW(Name, uint), /* raw binary str delimited by n hash symbols */
/* Name components */
/// An identifier contains an "is_mod_name" boolean,
/// indicating whether :: follows this token with no
/// whitespace in between.
IDENT(Ident, bool),
UNDERSCORE,
LIFETIME(Ident),
/* For interpolation */
INTERPOLATED(Nonterminal),
DOC_COMMENT(Name),
// Junk. These carry no data because we don't really care about the data
// they *would* carry, and don't really want to allocate a new ident for
// them. Instead, users could extract that from the associated span.
/// Whitespace
WS,
/// Comment
COMMENT,
SHEBANG(Name),
EOF,
}
#[deriving(Clone, Encodable, Decodable, PartialEq, Eq, Hash)]
/// For interpolation during macro expansion.
pub enum Nonterminal {
NtItem( P<ast::Item>),
NtBlock(P<ast::Block>),
NtStmt( P<ast::Stmt>),
NtPat( P<ast::Pat>),
NtExpr( P<ast::Expr>),
NtTy( P<ast::Ty>),
/// See IDENT, above, for meaning of bool in NtIdent:
NtIdent(Box<Ident>, bool),
/// Stuff inside brackets for attributes
NtMeta( P<ast::MetaItem>),
NtPath(Box<ast::Path>),
NtTT( P<ast::TokenTree>), // needs P'ed to break a circularity
NtMatchers(Vec<ast::Matcher>)
}
impl fmt::Show for Nonterminal {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
NtItem(..) => f.pad("NtItem(..)"),
NtBlock(..) => f.pad("NtBlock(..)"),
NtStmt(..) => f.pad("NtStmt(..)"),
NtPat(..) => f.pad("NtPat(..)"),
NtExpr(..) => f.pad("NtExpr(..)"),
NtTy(..) => f.pad("NtTy(..)"),
NtIdent(..) => f.pad("NtIdent(..)"),
NtMeta(..) => f.pad("NtMeta(..)"),
NtPath(..) => f.pad("NtPath(..)"),
NtTT(..) => f.pad("NtTT(..)"),
NtMatchers(..) => f.pad("NtMatchers(..)"),
}
}
}
pub fn binop_to_string(o: BinOp) -> &'static str {
match o {
PLUS => "+",
MINUS => "-",
STAR => "*",
SLASH => "/",
PERCENT => "%",
CARET => "^",
AND => "&",
OR => "|",
SHL => "<<",
SHR => ">>"
}
}
pub fn to_string(t: &Token) -> String {
match *t {
EQ => "=".into_string(),
LT => "<".into_string(),
LE => "<=".into_string(),
EQEQ => "==".into_string(),
NE => "!=".into_string(),
GE => ">=".into_string(),
GT => ">".into_string(),
NOT => "!".into_string(),
TILDE => "~".into_string(),
OROR => "||".into_string(),
ANDAND => "&&".into_string(),
BINOP(op) => binop_to_string(op).into_string(),
BINOPEQ(op) => {
let mut s = binop_to_string(op).into_string();
s.push_str("=");
s
}
/* Structural symbols */
AT => "@".into_string(),
DOT => ".".into_string(),
DOTDOT => "..".into_string(),
DOTDOTDOT => "...".into_string(),
COMMA => ",".into_string(),
SEMI => ";".into_string(),
COLON => ":".into_string(),
MOD_SEP => "::".into_string(),
RARROW => "->".into_string(),
LARROW => "<-".into_string(),
FAT_ARROW => "=>".into_string(),
LPAREN => "(".into_string(),
RPAREN => ")".into_string(),
LBRACKET => "[".into_string(),
RBRACKET => "]".into_string(),
LBRACE => "{".into_string(),
RBRACE => "}".into_string(),
POUND => "#".into_string(),
DOLLAR => "$".into_string(),
QUESTION => "?".into_string(),
/* Literals */
LIT_BYTE(b) => {
format!("b'{}'", b.as_str())
}
LIT_CHAR(c) => {
format!("'{}'", c.as_str())
}
LIT_INTEGER(c) | LIT_FLOAT(c) => {
c.as_str().into_string()
}
LIT_STR(s) => {
format!("\"{}\"", s.as_str())
}
LIT_STR_RAW(s, n) => {
format!("r{delim}\"{string}\"{delim}",
delim="#".repeat(n), string=s.as_str())
}
LIT_BINARY(v) => {
format!("b\"{}\"", v.as_str())
}
LIT_BINARY_RAW(s, n) => {
format!("br{delim}\"{string}\"{delim}",
delim="#".repeat(n), string=s.as_str())
}
/* Name components */
IDENT(s, _) => get_ident(s).get().into_string(),
LIFETIME(s) => {
format!("{}", get_ident(s))
}
UNDERSCORE => "_".into_string(),
/* Other */
DOC_COMMENT(s) => s.as_str().into_string(),
EOF => "<eof>".into_string(),
WS => " ".into_string(),
COMMENT => "/* */".into_string(),
SHEBANG(s) => format!("/* shebang: {}*/", s.as_str()),
INTERPOLATED(ref nt) => {
match nt {
&NtExpr(ref e) => ::print::pprust::expr_to_string(&**e),
&NtMeta(ref e) => ::print::pprust::meta_item_to_string(&**e),
&NtTy(ref e) => ::print::pprust::ty_to_string(&**e),
&NtPath(ref e) => ::print::pprust::path_to_string(&**e),
_ => {
let mut s = "an interpolated ".into_string();
match *nt {
NtItem(..) => s.push_str("item"),
NtBlock(..) => s.push_str("block"),
NtStmt(..) => s.push_str("statement"),
NtPat(..) => s.push_str("pattern"),
NtMeta(..) => fail!("should have been handled"),
NtExpr(..) => fail!("should have been handled"),
NtTy(..) => fail!("should have been handled"),
NtIdent(..) => s.push_str("identifier"),
NtPath(..) => fail!("should have been handled"),
NtTT(..) => s.push_str("tt"),
NtMatchers(..) => s.push_str("matcher sequence")
};
s
}
}
}
}
}
pub fn can_begin_expr(t: &Token) -> bool {
match *t {
LPAREN => true,
LBRACE => true,
LBRACKET => true,
IDENT(_, _) => true,
UNDERSCORE => true,
TILDE => true,
LIT_BYTE(_) => true,
LIT_CHAR(_) => true,
LIT_INTEGER(_) => true,
LIT_FLOAT(_) => true,
LIT_STR(_) => true,
LIT_STR_RAW(_, _) => true,
LIT_BINARY(_) => true,
LIT_BINARY_RAW(_, _) => true,
POUND => true,
AT => true,
NOT => true,
BINOP(MINUS) => true,
BINOP(STAR) => true,
BINOP(AND) => true,
BINOP(OR) => true, // in lambda syntax
OROR => true, // in lambda syntax
MOD_SEP => true,
INTERPOLATED(NtExpr(..))
| INTERPOLATED(NtIdent(..))
| INTERPOLATED(NtBlock(..))
| INTERPOLATED(NtPath(..)) => true,
_ => false
}
}
/// Returns the matching close delimiter if this is an open delimiter,
/// otherwise `None`.
pub fn close_delimiter_for(t: &Token) -> Option<Token> {
match *t {
LPAREN => Some(RPAREN),
LBRACE => Some(RBRACE),
LBRACKET => Some(RBRACKET),
_ => None
}
}
pub fn is_lit(t: &Token) -> bool {
match *t {
LIT_BYTE(_) => true,
LIT_CHAR(_) => true,
LIT_INTEGER(_) => true,
LIT_FLOAT(_) => true,
LIT_STR(_) => true,
LIT_STR_RAW(_, _) => true,
LIT_BINARY(_) => true,
LIT_BINARY_RAW(_, _) => true,
_ => false
}
}
pub fn is_ident(t: &Token) -> bool {
match *t { IDENT(_, _) => true, _ => false }
}
pub fn is_ident_or_path(t: &Token) -> bool {
match *t {
IDENT(_, _) | INTERPOLATED(NtPath(..)) => true,
_ => false
}
}
pub fn is_plain_ident(t: &Token) -> bool {
match *t { IDENT(_, false) => true, _ => false }
}
// Get the first "argument"
macro_rules! first {
( $first:expr, $( $remainder:expr, )* ) => ( $first )
}
// Get the last "argument" (has to be done recursively to avoid phoney local ambiguity error)
macro_rules! last {
( $first:expr, $( $remainder:expr, )+ ) => ( last!( $( $remainder, )+ ) );
( $first:expr, ) => ( $first )
}
// In this macro, there is the requirement that the name (the number) must be monotonically
// increasing by one in the special identifiers, starting at 0; the same holds for the keywords,
// except starting from the next number instead of zero, and with the additional exception that
// special identifiers are *also* allowed (they are deduplicated in the important place, the
// interner), an exception which is demonstrated by "static" and "self".
macro_rules! declare_special_idents_and_keywords {(
// So now, in these rules, why is each definition parenthesised?
// Answer: otherwise we get a spurious local ambiguity bug on the "}"
pub mod special_idents {
$( ($si_name:expr, $si_static:ident, $si_str:expr); )*
}
pub mod keywords {
'strict:
$( ($sk_name:expr, $sk_variant:ident, $sk_str:expr); )*
'reserved:
$( ($rk_name:expr, $rk_variant:ident, $rk_str:expr); )*
}
) => {
static STRICT_KEYWORD_START: Name = first!($( Name($sk_name), )*);
static STRICT_KEYWORD_FINAL: Name = last!($( Name($sk_name), )*);
static RESERVED_KEYWORD_START: Name = first!($( Name($rk_name), )*);
static RESERVED_KEYWORD_FINAL: Name = last!($( Name($rk_name), )*);
pub mod special_idents {
use ast::{Ident, Name};
$( pub static $si_static: Ident = Ident { name: Name($si_name), ctxt: 0 }; )*
}
pub mod special_names {
use ast::Name;
$( pub static $si_static: Name = Name($si_name); )*
}
/**
* All the valid words that have meaning in the Rust language.
*
* Rust keywords are either 'strict' or 'reserved'. Strict keywords may not
* appear as identifiers at all. Reserved keywords are not used anywhere in
* the language and may not appear as identifiers.
*/
pub mod keywords {
use ast::Name;
pub enum Keyword {
$( $sk_variant, )*
$( $rk_variant, )*
}
impl Keyword {
pub fn to_name(&self) -> Name {
match *self {
$( $sk_variant => Name($sk_name), )*
$( $rk_variant => Name($rk_name), )*
}
}
}
}
fn mk_fresh_ident_interner() -> IdentInterner {
// The indices here must correspond to the numbers in
// special_idents, in Keyword to_name(), and in static
// constants below.
let mut init_vec = Vec::new();
$(init_vec.push($si_str);)*
$(init_vec.push($sk_str);)*
$(init_vec.push($rk_str);)*
interner::StrInterner::prefill(init_vec.as_slice())
}
}}
// If the special idents get renumbered, remember to modify these two as appropriate
pub static SELF_KEYWORD_NAME: Name = Name(SELF_KEYWORD_NAME_NUM);
static STATIC_KEYWORD_NAME: Name = Name(STATIC_KEYWORD_NAME_NUM);
static SUPER_KEYWORD_NAME: Name = Name(SUPER_KEYWORD_NAME_NUM);
pub static SELF_KEYWORD_NAME_NUM: u32 = 1;
static STATIC_KEYWORD_NAME_NUM: u32 = 2;
static SUPER_KEYWORD_NAME_NUM: u32 = 3;
// NB: leaving holes in the ident table is bad! a different ident will get
// interned with the id from the hole, but it will be between the min and max
// of the reserved words, and thus tagged as "reserved".
declare_special_idents_and_keywords! {
pub mod special_idents {
// These ones are statics
(0, invalid, "");
(super::SELF_KEYWORD_NAME_NUM, self_, "self");
(super::STATIC_KEYWORD_NAME_NUM, statik, "static");
(super::SUPER_KEYWORD_NAME_NUM, super_, "super");
(4, static_lifetime, "'static");
// for matcher NTs
(5, tt, "tt");
(6, matchers, "matchers");
// outside of libsyntax
(7, clownshoe_abi, "__rust_abi");
(8, opaque, "<opaque>");
(9, unnamed_field, "<unnamed_field>");
(10, type_self, "Self");
(11, prelude_import, "prelude_import");
}
pub mod keywords {
// These ones are variants of the Keyword enum
'strict:
(12, As, "as");
(13, Break, "break");
(14, Crate, "crate");
(15, Else, "else");
(16, Enum, "enum");
(17, Extern, "extern");
(18, False, "false");
(19, Fn, "fn");
(20, For, "for");
(21, If, "if");
(22, Impl, "impl");
(23, In, "in");
(24, Let, "let");
(25, Loop, "loop");
(26, Match, "match");
(27, Mod, "mod");
(28, Move, "move");
(29, Mut, "mut");
(30, Once, "once");
(31, Pub, "pub");
(32, Ref, "ref");
(33, Return, "return");
// Static and Self are also special idents (prefill de-dupes)
(super::STATIC_KEYWORD_NAME_NUM, Static, "static");
(super::SELF_KEYWORD_NAME_NUM, Self, "self");
(34, Struct, "struct");
(super::SUPER_KEYWORD_NAME_NUM, Super, "super");
(35, True, "true");
(36, Trait, "trait");
(37, Type, "type");
(38, Unsafe, "unsafe");
(39, Use, "use");
(40, Virtual, "virtual");
(41, While, "while");
(42, Continue, "continue");
(43, Proc, "proc");
(44, Box, "box");
(45, Const, "const");
(46, Where, "where");
'reserved:
(47, Alignof, "alignof");
(48, Be, "be");
(49, Offsetof, "offsetof");
(50, Priv, "priv");
(51, Pure, "pure");
(52, Sizeof, "sizeof");
(53, Typeof, "typeof");
(54, Unsized, "unsized");
(55, Yield, "yield");
(56, Do, "do");
}
}
/**
* Maps a token to a record specifying the corresponding binary
* operator
*/
pub fn token_to_binop(tok: &Token) -> Option<ast::BinOp> {
match *tok {
BINOP(STAR) => Some(ast::BiMul),
BINOP(SLASH) => Some(ast::BiDiv),
BINOP(PERCENT) => Some(ast::BiRem),
BINOP(PLUS) => Some(ast::BiAdd),
BINOP(MINUS) => Some(ast::BiSub),
BINOP(SHL) => Some(ast::BiShl),
BINOP(SHR) => Some(ast::BiShr),
BINOP(AND) => Some(ast::BiBitAnd),
BINOP(CARET) => Some(ast::BiBitXor),
BINOP(OR) => Some(ast::BiBitOr),
LT => Some(ast::BiLt),
LE => Some(ast::BiLe),
GE => Some(ast::BiGe),
GT => Some(ast::BiGt),
EQEQ => Some(ast::BiEq),
NE => Some(ast::BiNe),
ANDAND => Some(ast::BiAnd),
OROR => Some(ast::BiOr),
_ => None
}
}
// looks like we can get rid of this completely...
pub type IdentInterner = StrInterner;
// if an interner exists in TLS, return it. Otherwise, prepare a
// fresh one.
// FIXME(eddyb) #8726 This should probably use a task-local reference.
pub fn get_ident_interner() -> Rc<IdentInterner> {
local_data_key!(key: Rc<::parse::token::IdentInterner>)
match key.get() {
Some(interner) => interner.clone(),
None => {
let interner = Rc::new(mk_fresh_ident_interner());
key.replace(Some(interner.clone()));
interner
}
}
}
/// Represents a string stored in the task-local interner. Because the
/// interner lives for the life of the task, this can be safely treated as an
/// immortal string, as long as it never crosses between tasks.
///
/// FIXME(pcwalton): You must be careful about what you do in the destructors
/// of objects stored in TLS, because they may run after the interner is
/// destroyed. In particular, they must not access string contents. This can
/// be fixed in the future by just leaking all strings until task death
/// somehow.
#[deriving(Clone, PartialEq, Hash, PartialOrd, Eq, Ord)]
pub struct InternedString {
string: RcStr,
}
impl InternedString {
#[inline]
pub fn new(string: &'static str) -> InternedString {
InternedString {
string: RcStr::new(string),
}
}
#[inline]
fn new_from_rc_str(string: RcStr) -> InternedString {
InternedString {
string: string,
}
}
#[inline]
pub fn get<'a>(&'a self) -> &'a str {
self.string.as_slice()
}
}
impl BytesContainer for InternedString {
fn container_as_bytes<'a>(&'a self) -> &'a [u8] {
// FIXME(pcwalton): This is a workaround for the incorrect signature
// of `BytesContainer`, which is itself a workaround for the lack of
// DST.
unsafe {
let this = self.get();
mem::transmute(this.container_as_bytes())
}
}
}
impl fmt::Show for InternedString {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self.string.as_slice())
}
}
impl<'a> Equiv<&'a str> for InternedString {
fn equiv(&self, other: & &'a str) -> bool {
(*other) == self.string.as_slice()
}
}
impl<D:Decoder<E>, E> Decodable<D, E> for InternedString {
fn decode(d: &mut D) -> Result<InternedString, E> {
Ok(get_name(get_ident_interner().intern(
try!(d.read_str()).as_slice())))
}
}
impl<S:Encoder<E>, E> Encodable<S, E> for InternedString {
fn encode(&self, s: &mut S) -> Result<(), E> {
s.emit_str(self.string.as_slice())
}
}
/// Returns the string contents of a name, using the task-local interner.
#[inline]
pub fn get_name(name: Name) -> InternedString {
let interner = get_ident_interner();
InternedString::new_from_rc_str(interner.get(name))
}
/// Returns the string contents of an identifier, using the task-local
/// interner.
#[inline]
pub fn get_ident(ident: Ident) -> InternedString {
get_name(ident.name)
}
/// Interns and returns the string contents of an identifier, using the
/// task-local interner.
#[inline]
pub fn intern_and_get_ident(s: &str) -> InternedString {
get_name(intern(s))
}
/// Maps a string to its interned representation.
#[inline]
pub fn intern(s: &str) -> Name {
get_ident_interner().intern(s)
}
/// gensym's a new uint, using the current interner.
#[inline]
pub fn gensym(s: &str) -> Name {
get_ident_interner().gensym(s)
}
/// Maps a string to an identifier with an empty syntax context.
#[inline]
pub fn str_to_ident(s: &str) -> Ident {
Ident::new(intern(s))
}
/// Maps a string to a gensym'ed identifier.
#[inline]
pub fn gensym_ident(s: &str) -> Ident {
Ident::new(gensym(s))
}
// create a fresh name that maps to the same string as the old one.
// note that this guarantees that str_ptr_eq(ident_to_string(src),interner_get(fresh_name(src)));
// that is, that the new name and the old one are connected to ptr_eq strings.
pub fn fresh_name(src: &Ident) -> Name {
let interner = get_ident_interner();
interner.gensym_copy(src.name)
// following: debug version. Could work in final except that it's incompatible with
// good error messages and uses of struct names in ambiguous could-be-binding
// locations. Also definitely destroys the guarantee given above about ptr_eq.
/*let num = rand::task_rng().gen_uint_range(0,0xffff);
gensym(format!("{}_{}",ident_to_string(src),num))*/
}
// create a fresh mark.
pub fn fresh_mark() -> Mrk {
gensym("mark").uint() as u32
}
// See the macro above about the types of keywords
pub fn is_keyword(kw: keywords::Keyword, tok: &Token) -> bool {
match *tok {
token::IDENT(sid, false) => { kw.to_name() == sid.name }
_ => { false }
}
}
pub fn is_any_keyword(tok: &Token) -> bool {
match *tok {
token::IDENT(sid, false) => {
let n = sid.name;
n == SELF_KEYWORD_NAME
|| n == STATIC_KEYWORD_NAME
|| n == SUPER_KEYWORD_NAME
|| STRICT_KEYWORD_START <= n
&& n <= RESERVED_KEYWORD_FINAL
},
_ => false
}
}
pub fn is_strict_keyword(tok: &Token) -> bool {
match *tok {
token::IDENT(sid, false) => {
let n = sid.name;
n == SELF_KEYWORD_NAME
|| n == STATIC_KEYWORD_NAME
|| n == SUPER_KEYWORD_NAME
|| STRICT_KEYWORD_START <= n
&& n <= STRICT_KEYWORD_FINAL
},
token::IDENT(sid, true) => {
let n = sid.name;
n != SELF_KEYWORD_NAME
&& n != SUPER_KEYWORD_NAME
&& STRICT_KEYWORD_START <= n
&& n <= STRICT_KEYWORD_FINAL
}
_ => false,
}
}
pub fn is_reserved_keyword(tok: &Token) -> bool {
match *tok {
token::IDENT(sid, false) => {
let n = sid.name;
RESERVED_KEYWORD_START <= n
&& n <= RESERVED_KEYWORD_FINAL
},
_ => false,
}
}
pub fn mtwt_token_eq(t1 : &Token, t2 : &Token) -> bool {
match (t1,t2) {
(&IDENT(id1,_),&IDENT(id2,_)) | (&LIFETIME(id1),&LIFETIME(id2)) =>
mtwt::resolve(id1) == mtwt::resolve(id2),
_ => *t1 == *t2
}
}
#[cfg(test)]
mod test {
use super::*;
use ast;
use ext::mtwt;
fn mark_ident(id : ast::Ident, m : ast::Mrk) -> ast::Ident {
ast::Ident { name: id.name, ctxt:mtwt::apply_mark(m, id.ctxt) }
}
#[test] fn mtwt_token_eq_test() {
assert!(mtwt_token_eq(&GT,&GT));
let a = str_to_ident("bac");
let a1 = mark_ident(a,92);
assert!(mtwt_token_eq(&IDENT(a,true),&IDENT(a1,false)));
}
}