bjoernager/rust
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librustc: Change labels to use the lifetime notation '.

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This commit is contained in:
Patrick Walton 2013-04-26 16:19:26 -07:00
parent 876483dcf4
commit 670ab8ac36
6 changed files with 79 additions and 40 deletions
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57
src/libsyntax/parse/parser.rs
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@ -348,6 +348,20 @@ pub impl Parser {
self.token_is_keyword(&~"fn", tok)
}
fn token_is_lifetime(&self, tok: &token::Token) -> bool {
match *tok {
token::LIFETIME(*) => true,
_ => false,
}
}
fn get_lifetime(&self, tok: &token::Token) -> ast::ident {
match *tok {
token::LIFETIME(ref ident) => copy *ident,
_ => self.bug(~"not a lifetime"),
}
}
// parse a ty_bare_fun type:
fn parse_ty_bare_fn(&self) -> ty_
{
@ -1228,8 +1242,14 @@ pub impl Parser {
expr_do_body);
} else if self.eat_keyword(&~"while") {
return self.parse_while_expr();
} else if self.token_is_lifetime(&*self.token) {
let lifetime = self.get_lifetime(&*self.token);
self.bump();
self.expect(&token::COLON);
self.expect_keyword(&~"loop");
return self.parse_loop_expr(Some(lifetime));
} else if self.eat_keyword(&~"loop") {
return self.parse_loop_expr();
return self.parse_loop_expr(None);
} else if self.eat_keyword(&~"match") {
return self.parse_match_expr();
} else if self.eat_keyword(&~"unsafe") {
@ -1290,8 +1310,10 @@ pub impl Parser {
} else { ex = expr_ret(None); }
} else if self.eat_keyword(&~"break") {
// BREAK expression
if is_ident(&*self.token) {
ex = expr_break(Some(self.parse_ident()));
if self.token_is_lifetime(&*self.token) {
let lifetime = self.get_lifetime(&*self.token);
self.bump();
ex = expr_break(Some(lifetime));
} else {
ex = expr_break(None);
}
@ -1995,37 +2017,32 @@ pub impl Parser {
return self.mk_expr(lo, hi, expr_while(cond, body));
}
fn parse_loop_expr(&self) -> @expr {
fn parse_loop_expr(&self, opt_ident: Option<ast::ident>) -> @expr {
// loop headers look like 'loop {' or 'loop unsafe {'
let is_loop_header =
*self.token == token::LBRACE
|| (is_ident(&*self.token)
&& self.look_ahead(1) == token::LBRACE);
// labeled loop headers look like 'loop foo: {'
let is_labeled_loop_header =
is_ident(&*self.token)
&& !self.is_any_keyword(&copy *self.token)
&& self.look_ahead(1) == token::COLON;
if is_loop_header || is_labeled_loop_header {
if is_loop_header {
// This is a loop body
let opt_ident;
if is_labeled_loop_header {
opt_ident = Some(self.parse_ident());
self.expect(&token::COLON);
} else {
opt_ident = None;
}
let lo = self.last_span.lo;
let body = self.parse_block();
let hi = body.span.hi;
return self.mk_expr(lo, hi, expr_loop(body, opt_ident));
} else {
// This is a 'continue' expression
if opt_ident.is_some() {
self.span_err(*self.last_span,
~"a label may not be used with a `loop` \
expression");
}
let lo = self.span.lo;
let ex = if is_ident(&*self.token) {
expr_again(Some(self.parse_ident()))
let ex = if self.token_is_lifetime(&*self.token) {
let lifetime = self.get_lifetime(&*self.token);
self.bump();
expr_again(Some(lifetime))
} else {
expr_again(None)
};