bjoernager/rust
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Parse 'loop' and 'again' the same

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This commit is contained in:
Brian Anderson 2012-09-04 13:36:54 -07:00
parent 443f79922d
commit d3e75ea375
4 changed files with 42 additions and 23 deletions
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55
src/libsyntax/parse/parser.rs
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@ -883,7 +883,7 @@ struct parser {
return pexpr(self.parse_sugary_call_expr(~"do", expr_do_body));
} else if self.eat_keyword(~"while") {
return pexpr(self.parse_while_expr());
} else if self.eat_keyword(~"loop") {
} else if self.eat_keyword(~"again") || self.eat_keyword(~"loop") {
return pexpr(self.parse_loop_expr());
} else if self.eat_keyword(~"match") {
return pexpr(self.parse_alt_expr());
@ -969,13 +969,6 @@ struct parser {
ex = expr_break(None);
}
hi = self.span.hi;
} else if self.eat_keyword(~"again") {
if is_ident(self.token) {
ex = expr_again(Some(self.parse_ident()));
} else {
ex = expr_again(None);
}
hi = self.span.hi;
} else if self.eat_keyword(~"copy") {
let e = self.parse_expr();
ex = expr_copy(e);
@ -1609,18 +1602,42 @@ struct parser {
}
fn parse_loop_expr() -> @expr {
let opt_ident;
if is_ident(self.token) && !self.is_any_keyword(copy self.token) {
opt_ident = Some(self.parse_ident());
self.expect(token::COLON);
} else {
opt_ident = None;
}
// loop headers look like 'loop {' or 'loop unsafe {'
let is_loop_header =
self.token == token::LBRACE
|| (is_ident(copy 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;
let lo = self.last_span.lo;
let body = self.parse_block_no_value();
let mut hi = body.span.hi;
return self.mk_expr(lo, hi, expr_loop(body, opt_ident));
if is_loop_header || is_labeled_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_no_value();
let mut hi = body.span.hi;
return self.mk_expr(lo, hi, expr_loop(body, opt_ident));
} else {
// This is a 'continue' expression
let lo = self.span.lo;
let ex = if is_ident(self.token) {
expr_again(Some(self.parse_ident()))
} else {
expr_again(None)
};
let hi = self.span.hi;
return self.mk_expr(lo, hi, ex);
}
}
// For distingishing between record literals and blocks