diff options
Diffstat (limited to 'src/libsyntax/parse/parser.rs')
| -rw-r--r-- | src/libsyntax/parse/parser.rs | 148 |
1 files changed, 89 insertions, 59 deletions
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index aaafbf0ef24..89053c4eb1d 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -15,14 +15,12 @@ import common::{seq_sep_trailing_disallowed, seq_sep_trailing_allowed, import dvec::{dvec, extensions}; import vec::{push}; import ast::{_mod, add, alt_check, alt_exhaustive, arg, arm, attribute, - bitand, bitor, bitxor, blk, blk_check_mode, bound_const, - bound_copy, bound_send, bound_trait, bound_owned, - box, by_copy, by_move, - by_mutbl_ref, by_ref, by_val, capture_clause, capture_item, - cdir_dir_mod, cdir_src_mod, - cdir_view_item, class_immutable, - class_member, class_method, class_mutable, - crate, crate_cfg, crate_directive, decl, + bind_by_ref, bind_by_value, bitand, bitor, bitxor, blk, + blk_check_mode, bound_const, bound_copy, bound_send, bound_trait, + bound_owned, box, by_copy, by_move, by_mutbl_ref, by_ref, by_val, + capture_clause, capture_item, cdir_dir_mod, cdir_src_mod, + cdir_view_item, class_immutable, class_member, class_method, + class_mutable, crate, crate_cfg, crate_directive, decl, decl_item, decl_local, default_blk, deref, div, expl, expr, expr_, expr_addr_of, expr_alt, expr_again, expr_assert, expr_assign, expr_assign_op, expr_binary, expr_block, expr_break, @@ -1585,13 +1583,13 @@ class parser { fn parse_pats() -> ~[@pat] { let mut pats = ~[]; loop { - vec::push(pats, self.parse_pat()); + vec::push(pats, self.parse_pat(true)); if self.token == token::BINOP(token::OR) { self.bump(); } else { ret pats; } }; } - fn parse_pat() -> @pat { + fn parse_pat(refutable: bool) -> @pat { let lo = self.span.lo; let mut hi = self.span.hi; let mut pat; @@ -1599,7 +1597,7 @@ class parser { token::UNDERSCORE { self.bump(); pat = pat_wild; } token::AT { self.bump(); - let sub = self.parse_pat(); + let sub = self.parse_pat(refutable); hi = sub.span.hi; // HACK: parse @"..." as a literal of a vstore @str pat = alt sub.node { @@ -1614,7 +1612,7 @@ class parser { } token::TILDE { self.bump(); - let sub = self.parse_pat(); + let sub = self.parse_pat(refutable); hi = sub.span.hi; // HACK: parse ~"..." as a literal of a vstore ~str pat = alt sub.node { @@ -1660,11 +1658,13 @@ class parser { let mut subpat; if self.token == token::COLON { self.bump(); - subpat = self.parse_pat(); + subpat = self.parse_pat(refutable); } else { - subpat = @{id: self.get_id(), - node: pat_ident(fieldpath, none), - span: mk_sp(lo, hi)}; + subpat = @{ + id: self.get_id(), + node: pat_ident(bind_by_ref, fieldpath, none), + span: mk_sp(lo, hi) + }; } vec::push(fields, {ident: fieldname, pat: subpat}); } @@ -1681,10 +1681,10 @@ class parser { let expr = self.mk_expr(lo, hi, expr_lit(lit)); pat = pat_lit(expr); } else { - let mut fields = ~[self.parse_pat()]; + let mut fields = ~[self.parse_pat(refutable)]; while self.token == token::COMMA { self.bump(); - vec::push(fields, self.parse_pat()); + vec::push(fields, self.parse_pat(refutable)); } if vec::len(fields) == 1u { self.expect(token::COMMA); } hi = self.span.hi; @@ -1704,50 +1704,80 @@ class parser { hi = val.span.hi; pat = pat_lit(val); } - } else if is_plain_ident(self.token) && - alt self.look_ahead(1u) { - token::LPAREN | token::LBRACKET | token::LT { false } - _ { true } - } { - let name = self.parse_value_path(); - let sub = if self.eat(token::AT) { some(self.parse_pat()) } - else { none }; - pat = pat_ident(name, sub); } else { - let enum_path = self.parse_path_with_tps(true); - hi = enum_path.span.hi; - let mut args: ~[@pat] = ~[]; - let mut star_pat = false; - alt self.token { - token::LPAREN { - alt self.look_ahead(1u) { - token::BINOP(token::STAR) { - // This is a "top constructor only" pat - self.bump(); self.bump(); - star_pat = true; - self.expect(token::RPAREN); + let binding_mode; + if self.eat_keyword(~"ref") { + binding_mode = bind_by_ref; + } else { + alt self.token { + token::BINOP(token::PLUS) => { + // XXX: Temporary thing pending a snapshot. + self.bump(); + binding_mode = bind_by_value; + } + _ if refutable => { + // XXX: Should be bind_by_value, but that's not + // backward compatible. + binding_mode = bind_by_ref; + } + _ => { + binding_mode = bind_by_value; + } + } + } + + if is_plain_ident(self.token) && + alt self.look_ahead(1) { + token::LPAREN | token::LBRACKET | token::LT => { + false } - _ { - args = self.parse_unspanned_seq( - token::LPAREN, token::RPAREN, - seq_sep_trailing_disallowed(token::COMMA), - |p| p.parse_pat()); - hi = self.span.hi; + _ => { + true } + } { + let name = self.parse_value_path(); + let sub = if self.eat(token::AT) { + some(self.parse_pat(refutable)) + } + else { none }; + pat = pat_ident(binding_mode, name, sub); + } else { + let enum_path = self.parse_path_with_tps(true); + hi = enum_path.span.hi; + let mut args: ~[@pat] = ~[]; + let mut star_pat = false; + alt self.token { + token::LPAREN { + alt self.look_ahead(1u) { + token::BINOP(token::STAR) { + // This is a "top constructor only" pat + self.bump(); self.bump(); + star_pat = true; + self.expect(token::RPAREN); + } + _ { + args = self.parse_unspanned_seq( + token::LPAREN, token::RPAREN, + seq_sep_trailing_disallowed(token::COMMA), + |p| p.parse_pat(refutable)); + hi = self.span.hi; + } + } + } + _ { } + } + // at this point, we're not sure whether it's a enum or a + // bind + if star_pat { + pat = pat_enum(enum_path, none); + } + else if vec::is_empty(args) && + vec::len(enum_path.idents) == 1u { + pat = pat_ident(binding_mode, enum_path, none); + } + else { + pat = pat_enum(enum_path, some(args)); } - } - _ { } - } - // at this point, we're not sure whether it's a enum or a bind - if star_pat { - pat = pat_enum(enum_path, none); - } - else if vec::is_empty(args) && - vec::len(enum_path.idents) == 1u { - pat = pat_ident(enum_path, none); - } - else { - pat = pat_enum(enum_path, some(args)); } } } @@ -1758,7 +1788,7 @@ class parser { fn parse_local(is_mutbl: bool, allow_init: bool) -> @local { let lo = self.span.lo; - let pat = self.parse_pat(); + let pat = self.parse_pat(false); let mut ty = @{id: self.get_id(), node: ty_infer, span: mk_sp(lo, lo)}; |