Starting on support for anonymous objects. Just syntax so far.

This commit is contained in:
Lindsey Kuper 2011-05-06 17:08:41 -07:00 committed by Graydon Hoare
parent ae784df3ce
commit 7c2979e26f
3 changed files with 96 additions and 0 deletions

View file

@ -296,6 +296,7 @@ tag expr_ {
expr_check(@expr, ann);
expr_port(ann);
expr_chan(@expr, ann);
expr_anon_obj(anon_obj, vec[ty_param], obj_def_ids, ann);
}
type lit = spanned[lit_];
@ -371,6 +372,25 @@ type _obj = rec(vec[obj_field] fields,
vec[@method] methods,
option::t[@method] dtor);
// Hmm. An anon_obj might extend an existing object, in which case it'll
// probably add fields and methods.
type anon_obj = rec(option.t[vec[obj_field]] fields,
vec[@method] methods,
option.t[ident] with_obj);
tag mod_index_entry {
mie_view_item(@view_item);
mie_item(@item);
mie_tag_variant(@item /* tag item */, uint /* variant index */);
}
tag native_mod_index_entry {
nmie_view_item(@view_item);
nmie_item(@native_item);
}
type mod_index = hashmap[ident,mod_index_entry];
type _mod = rec(vec[@view_item] view_items,
vec[@item] items);

View file

@ -799,6 +799,56 @@ fn parse_bottom_expr(parser p) -> @ast::expr {
}
ex = ast::expr_rec(fields, base, p.get_ann());
}
// Anonymous object
else if (eat_word(p, "obj")) {
// FIXME: Can anonymous objects have ty params?
auto ty_params = parse_ty_params(p);
// Only make people type () if they're actually adding new fields
let option.t[vec[ast.obj_field]] fields = none[vec[ast.obj_field]];
if (p.peek() == token.LPAREN) {
auto pf = parse_obj_field;
hi = p.get_hi_pos();
expect(p, token.LPAREN);
fields = some[vec[ast.obj_field]]
(parse_seq_to_end[ast.obj_field]
(token.RPAREN,
some(token.COMMA),
pf, hi, p));
}
let vec[@ast.method] meths = vec();
let option.t[ast.ident] with_obj = none[ast.ident];
expect(p, token.LBRACE);
while (p.peek() != token.RBRACE) {
alt (p.peek()) {
case (token.WITH) {
with_obj = some[ast.ident](parse_ident(p));
}
case (_) {
// fall through
}
}
}
hi = p.get_hi_pos();
expect(p, token.RBRACE);
// fields and methods may be *additional* or *overriding* fields
// and methods if there's a with_obj, or they may be the *only*
// fields and methods if there's no with_obj.
// We don't need to pull ".node" out of fields because it's not a
// "spanned".
let ast.anon_obj ob = rec(fields=fields,
methods=meths,
with_obj=with_obj);
auto odid = rec(ty=p.next_def_id(), ctor=p.next_def_id());
ex = ast.expr_anon_obj(ob, ty_params, odid, ast.ann_none);
} else if (eat_word(p, "bind")) {
auto e = parse_expr_res(p, RESTRICT_NO_CALL_EXPRS);
fn parse_expr_opt(parser p) -> option::t[@ast::expr] {

View file

@ -0,0 +1,26 @@
// xfail-boot
// xfail-stage0
use std;
import std._vec.len;
fn main() {
obj a() {
fn foo() -> int {
ret 2;
}
fn bar() -> int {
ret self.foo();
}
}
auto my_a = a();
// Step 1 is to add support for this "with" syntax
auto my_b = obj {
fn baz() -> int {
ret self.foo();
}
with my_a
};
}