Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Use an enum for keywords and intern them to improve parser performance #6737

Closed
wants to merge 1 commit into from
Closed

Use an enum for keywords and intern them to improve parser performance #6737

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 3 additions & 2 deletions src/libsyntax/ext/trace_macros.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@ use ext::base::ExtCtxt;
use ext::base;
use parse::lexer::{new_tt_reader, reader};
use parse::parser::Parser;
use parse::token::keywords;

pub fn expand_trace_macros(cx: @ExtCtxt,
sp: span,
Expand All @@ -36,9 +37,9 @@ pub fn expand_trace_macros(cx: @ExtCtxt,
rdr.dup()
);

if rust_parser.is_keyword("true") {
if rust_parser.is_keyword(keywords::True) {
cx.set_trace_macros(true);
} else if rust_parser.is_keyword("false") {
} else if rust_parser.is_keyword(keywords::False) {
cx.set_trace_macros(false);
} else {
cx.span_fatal(sp, "trace_macros! only accepts `true` or `false`")
Expand Down
97 changes: 13 additions & 84 deletions src/libsyntax/parse/common.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@ use ast;
use codemap::{BytePos, spanned};
use parse::lexer::reader;
use parse::parser::Parser;
use parse::token::keywords;
use parse::token;

use opt_vec;
Expand Down Expand Up @@ -133,54 +134,15 @@ pub impl Parser {
return if *self.token == *tok { self.bump(); true } else { false };
}

// Storing keywords as interned idents instead of strings would be nifty.

// A sanity check that the word we are asking for is a known keyword
// NOTE: this could be done statically....
fn require_keyword(&self, word: &str) {
if !self.keywords.contains_equiv(&word) {
self.bug(fmt!("unknown keyword: %s", word));
}
}

// return true when this token represents the given string, and is not
// followed immediately by :: .
fn token_is_word(&self, word: &str, tok: &token::Token) -> bool {
match *tok {
token::IDENT(sid, false) => { word == *self.id_to_str(sid) }
_ => { false }
}
}

fn token_is_keyword(&self, word: &str, tok: &token::Token) -> bool {
self.require_keyword(word);
self.token_is_word(word, tok)
}

fn is_keyword(&self, word: &str) -> bool {
self.token_is_keyword(word, &copy *self.token)
}

fn id_is_any_keyword(&self, id: ast::ident) -> bool {
self.keywords.contains(self.id_to_str(id))
}

fn is_any_keyword(&self, tok: &token::Token) -> bool {
match *tok {
token::IDENT(sid, false) => {
self.keywords.contains(self.id_to_str(sid))
}
_ => false
}
fn is_keyword(&self, kw: keywords::Keyword) -> bool {
token::is_keyword(kw, self.token)
}

// if the given word is not a keyword, signal an error.
// if the next token is the given keyword, eat it and return
// true. Otherwise, return false.
fn eat_keyword(&self, word: &str) -> bool {
self.require_keyword(word);
fn eat_keyword(&self, kw: keywords::Keyword) -> bool {
let is_kw = match *self.token {
token::IDENT(sid, false) => word == *self.id_to_str(sid),
token::IDENT(sid, false) => kw.to_ident().repr == sid.repr,
_ => false
};
if is_kw { self.bump() }
Expand All @@ -190,63 +152,30 @@ pub impl Parser {
// if the given word is not a keyword, signal an error.
// if the next token is not the given word, signal an error.
// otherwise, eat it.
fn expect_keyword(&self, word: &str) {
self.require_keyword(word);
if !self.eat_keyword(word) {
fn expect_keyword(&self, kw: keywords::Keyword) {
if !self.eat_keyword(kw) {
self.fatal(
fmt!(
"expected `%s`, found `%s`",
word,
*self.id_to_str(kw.to_ident()),
self.this_token_to_str()
)
);
}
}

// return true if the given string is a strict keyword
fn is_strict_keyword(&self, word: &str) -> bool {
self.strict_keywords.contains_equiv(&word)
}

// signal an error if the current token is a strict keyword
fn check_strict_keywords(&self) {
match *self.token {
token::IDENT(_, false) => {
let w = token_to_str(self.reader, &copy *self.token);
self.check_strict_keywords_(w);
}
_ => ()
}
}

// signal an error if the given string is a strict keyword
fn check_strict_keywords_(&self, w: &str) {
if self.is_strict_keyword(w) {
fn check_strict_keywords(&self) {
if token::is_strict_keyword(self.token) {
self.span_err(*self.last_span,
fmt!("found `%s` in ident position", w));
fmt!("found `%s` in ident position", self.this_token_to_str()));
}
}

// return true if this is a reserved keyword
fn is_reserved_keyword(&self, word: &str) -> bool {
self.reserved_keywords.contains_equiv(&word)
}

// signal an error if the current token is a reserved keyword
fn check_reserved_keywords(&self) {
match *self.token {
token::IDENT(_, false) => {
let w = token_to_str(self.reader, &copy *self.token);
self.check_reserved_keywords_(w);
}
_ => ()
}
}

// signal an error if the given string is a reserved keyword
fn check_reserved_keywords_(&self, w: &str) {
if self.is_reserved_keyword(w) {
self.fatal(fmt!("`%s` is a reserved keyword", w));
if token::is_reserved_keyword(self.token) {
self.fatal(fmt!("`%s` is a reserved keyword", self.this_token_to_str()));
}
}

Expand Down
6 changes: 3 additions & 3 deletions src/libsyntax/parse/obsolete.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@ use ast::{expr, expr_lit, lit_nil, attribute};
use ast;
use codemap::{span, respan};
use parse::parser::Parser;
use parse::token::Token;
use parse::token::{keywords, Token};
use parse::token;

use core::to_bytes;
Expand Down Expand Up @@ -295,9 +295,9 @@ pub impl Parser {
}

fn try_parse_obsolete_priv_section(&self, attrs: &[attribute]) -> bool {
if self.is_keyword("priv") && self.look_ahead(1) == token::LBRACE {
if self.is_keyword(keywords::Priv) && self.look_ahead(1) == token::LBRACE {
self.obsolete(copy *self.span, ObsoletePrivSection);
self.eat_keyword("priv");
self.eat_keyword(keywords::Priv);
self.bump();
while *self.token != token::RBRACE {
self.parse_single_struct_field(ast::private, attrs.to_owned());
Expand Down
Loading