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| author | Graydon Hoare <graydon@mozilla.com> | 2012-02-29 11:46:23 -0800 |
|---|---|---|
| committer | Graydon Hoare <graydon@mozilla.com> | 2012-03-02 18:46:13 -0800 |
| commit | 87c14f1e3d85751bffffda0b1920be5e726172c4 (patch) | |
| tree | 371d86e9a7c65b06df5c8f5e6d499cf4730324fc /src/comp/syntax/parse/parser.rs | |
| parent | 9228947fe15af96593abf4745d91802b56c205e8 (diff) | |
| download | rust-87c14f1e3d85751bffffda0b1920be5e726172c4.tar.gz rust-87c14f1e3d85751bffffda0b1920be5e726172c4.zip | |
Move src/comp to src/rustc
Diffstat (limited to 'src/comp/syntax/parse/parser.rs')
| -rw-r--r-- | src/comp/syntax/parse/parser.rs | 2747 |
1 files changed, 0 insertions, 2747 deletions
diff --git a/src/comp/syntax/parse/parser.rs b/src/comp/syntax/parse/parser.rs deleted file mode 100644 index 5837baf1ff9..00000000000 --- a/src/comp/syntax/parse/parser.rs +++ /dev/null @@ -1,2747 +0,0 @@ -import std::{io, fs}; -import either::{left, right}; -import std::map::{hashmap, new_str_hash}; -import token::can_begin_expr; -import codemap::{span,fss_none}; -import util::interner; -import ast::{node_id, spanned}; -import ast_util::{mk_sp, ident_to_path}; -import front::attr; -import lexer::reader; -import driver::diagnostic; - -enum restriction { - UNRESTRICTED, - RESTRICT_STMT_EXPR, - RESTRICT_NO_CALL_EXPRS, - RESTRICT_NO_BAR_OP, -} - -enum file_type { CRATE_FILE, SOURCE_FILE, } - -type parse_sess = @{ - cm: codemap::codemap, - mutable next_id: node_id, - span_diagnostic: diagnostic::span_handler, - // these two must be kept up to date - mutable chpos: uint, - mutable byte_pos: uint -}; - -fn next_node_id(sess: parse_sess) -> node_id { - let rv = sess.next_id; - sess.next_id += 1; - // ID 0 is reserved for the crate and doesn't actually exist in the AST - assert rv != 0; - ret rv; -} - -type parser = @{ - sess: parse_sess, - cfg: ast::crate_cfg, - file_type: file_type, - mutable token: token::token, - mutable span: span, - mutable last_span: span, - mutable buffer: [{tok: token::token, span: span}], - mutable restriction: restriction, - reader: reader, - precs: @[op_spec], - bad_expr_words: hashmap<str, ()> -}; - -impl parser for parser { - fn bump() { - self.last_span = self.span; - if vec::len(self.buffer) == 0u { - let next = lexer::next_token(self.reader); - self.token = next.tok; - self.span = ast_util::mk_sp(next.chpos, self.reader.chpos); - } else { - let next = vec::pop(self.buffer); - self.token = next.tok; - self.span = next.span; - } - } - fn swap(next: token::token, lo: uint, hi: uint) { - self.token = next; - self.span = ast_util::mk_sp(lo, hi); - } - fn look_ahead(distance: uint) -> token::token { - while vec::len(self.buffer) < distance { - let next = lexer::next_token(self.reader); - let sp = ast_util::mk_sp(next.chpos, self.reader.chpos); - self.buffer = [{tok: next.tok, span: sp}] + self.buffer; - } - ret self.buffer[distance - 1u].tok; - } - fn fatal(m: str) -> ! { - self.sess.span_diagnostic.span_fatal(self.span, m) - } - fn span_fatal(sp: span, m: str) -> ! { - self.sess.span_diagnostic.span_fatal(sp, m) - } - fn warn(m: str) { - self.sess.span_diagnostic.span_warn(self.span, m) - } - fn get_str(i: token::str_num) -> str { - interner::get(*self.reader.interner, i) - } - fn get_id() -> node_id { next_node_id(self.sess) } -} - -fn new_parser_from_file(sess: parse_sess, cfg: ast::crate_cfg, path: str, - ftype: file_type) -> - parser { - let src = alt io::read_whole_file_str(path) { - result::ok(src) { - // FIXME: This copy is unfortunate - @src - } - result::err(e) { - sess.span_diagnostic.handler().fatal(e) - } - }; - let filemap = codemap::new_filemap(path, src, - sess.chpos, sess.byte_pos); - sess.cm.files += [filemap]; - let itr = @interner::mk(str::hash, str::eq); - let rdr = lexer::new_reader(sess.cm, sess.span_diagnostic, filemap, itr); - ret new_parser(sess, cfg, rdr, ftype); -} - -fn new_parser_from_source_str(sess: parse_sess, cfg: ast::crate_cfg, - name: str, ss: codemap::file_substr, - source: @str) -> parser { - let ftype = SOURCE_FILE; - let filemap = codemap::new_filemap_w_substr - (name, ss, source, sess.chpos, sess.byte_pos); - sess.cm.files += [filemap]; - let itr = @interner::mk(str::hash, str::eq); - let rdr = lexer::new_reader(sess.cm, sess.span_diagnostic, - filemap, itr); - ret new_parser(sess, cfg, rdr, ftype); -} - -fn new_parser(sess: parse_sess, cfg: ast::crate_cfg, rdr: reader, - ftype: file_type) -> parser { - let tok0 = lexer::next_token(rdr); - let span0 = ast_util::mk_sp(tok0.chpos, rdr.chpos); - @{sess: sess, - cfg: cfg, - file_type: ftype, - mutable token: tok0.tok, - mutable span: span0, - mutable last_span: span0, - mutable buffer: [], - mutable restriction: UNRESTRICTED, - reader: rdr, - precs: prec_table(), - bad_expr_words: bad_expr_word_table()} -} - -// These are the words that shouldn't be allowed as value identifiers, -// because, if used at the start of a line, they will cause the line to be -// interpreted as a specific kind of statement, which would be confusing. -fn bad_expr_word_table() -> hashmap<str, ()> { - let words = new_str_hash(); - for word in ["alt", "assert", "be", "break", "check", "claim", - "class", "const", "cont", "copy", "do", "else", "enum", - "export", "fail", "fn", "for", "if", "iface", "impl", - "import", "let", "log", "mod", "mutable", "native", "pure", - "resource", "ret", "trait", "type", "unchecked", "unsafe", - "while", "crust", "mut"] { - words.insert(word, ()); - } - words -} - -fn unexpected(p: parser, t: token::token) -> ! { - let s: str = "unexpected token: '" + token::to_str(p.reader, t) + - "'"; - p.fatal(s); -} - -fn expect(p: parser, t: token::token) { - if p.token == t { - p.bump(); - } else { - let s: str = "expecting '"; - s += token::to_str(p.reader, t); - s += "' but found '"; - s += token::to_str(p.reader, p.token); - p.fatal(s + "'"); - } -} - -fn expect_gt(p: parser) { - if p.token == token::GT { - p.bump(); - } else if p.token == token::BINOP(token::LSR) { - p.swap(token::GT, p.span.lo + 1u, p.span.hi); - } else if p.token == token::BINOP(token::ASR) { - p.swap(token::BINOP(token::LSR), p.span.lo + 1u, p.span.hi); - } else { - let s: str = "expecting "; - s += token::to_str(p.reader, token::GT); - s += ", found "; - s += token::to_str(p.reader, p.token); - p.fatal(s); - } -} - -fn spanned<T: copy>(lo: uint, hi: uint, node: T) -> spanned<T> { - ret {node: node, span: ast_util::mk_sp(lo, hi)}; -} - -fn parse_ident(p: parser) -> ast::ident { - alt p.token { - token::IDENT(i, _) { p.bump(); ret p.get_str(i); } - _ { p.fatal("expecting ident, found " - + token::to_str(p.reader, p.token)); } - } -} - -fn parse_path_list_ident(p: parser) -> ast::path_list_ident { - let lo = p.span.lo; - let ident = parse_ident(p); - let hi = p.span.hi; - ret spanned(lo, hi, {name: ident, id: p.get_id()}); -} - -fn parse_value_ident(p: parser) -> ast::ident { - check_bad_word(p); - ret parse_ident(p); -} - -fn eat(p: parser, tok: token::token) -> bool { - ret if p.token == tok { p.bump(); true } else { false }; -} - -fn is_word(p: parser, word: str) -> bool { - ret alt p.token { - token::IDENT(sid, false) { str::eq(word, p.get_str(sid)) } - _ { false } - }; -} - -fn eat_word(p: parser, word: str) -> bool { - alt p.token { - token::IDENT(sid, false) { - if str::eq(word, p.get_str(sid)) { - p.bump(); - ret true; - } else { ret false; } - } - _ { ret false; } - } -} - -fn expect_word(p: parser, word: str) { - if !eat_word(p, word) { - p.fatal("expecting " + word + ", found " + - token::to_str(p.reader, p.token)); - } -} - -fn check_bad_word(p: parser) { - alt p.token { - token::IDENT(sid, false) { - let w = p.get_str(sid); - if p.bad_expr_words.contains_key(w) { - p.fatal("found " + w + " in expression position"); - } - } - _ { } - } -} - -fn parse_ty_fn(p: parser) -> ast::fn_decl { - fn parse_fn_input_ty(p: parser) -> ast::arg { - let mode = parse_arg_mode(p); - let name = if is_plain_ident(p) && p.look_ahead(1u) == token::COLON { - let name = parse_value_ident(p); - p.bump(); - name - } else { "" }; - ret {mode: mode, ty: parse_ty(p, false), ident: name, id: p.get_id()}; - } - let inputs = - parse_seq(token::LPAREN, token::RPAREN, seq_sep(token::COMMA), - parse_fn_input_ty, p); - // FIXME: there's no syntax for this right now anyway - // auto constrs = parse_constrs(~[], p); - let constrs: [@ast::constr] = []; - let (ret_style, ret_ty) = parse_ret_ty(p); - ret {inputs: inputs.node, output: ret_ty, - purity: ast::impure_fn, cf: ret_style, - constraints: constrs}; -} - -fn parse_ty_methods(p: parser) -> [ast::ty_method] { - parse_seq(token::LBRACE, token::RBRACE, seq_sep_none(), {|p| - let attrs = parse_outer_attributes(p); - let flo = p.span.lo; - let pur = parse_fn_purity(p); - let ident = parse_method_name(p); - let tps = parse_ty_params(p); - let d = parse_ty_fn(p), fhi = p.last_span.hi; - expect(p, token::SEMI); - {ident: ident, attrs: attrs, decl: {purity: pur with d}, tps: tps, - span: ast_util::mk_sp(flo, fhi)} - }, p).node -} - -fn parse_mt(p: parser) -> ast::mt { - let mutbl = parse_mutability(p); - let t = parse_ty(p, false); - ret {ty: t, mutbl: mutbl}; -} - -fn parse_ty_field(p: parser) -> ast::ty_field { - let lo = p.span.lo; - let mutbl = parse_mutability(p); - let id = parse_ident(p); - expect(p, token::COLON); - let ty = parse_ty(p, false); - ret spanned(lo, ty.span.hi, {ident: id, mt: {ty: ty, mutbl: mutbl}}); -} - -// if i is the jth ident in args, return j -// otherwise, fail -fn ident_index(p: parser, args: [ast::arg], i: ast::ident) -> uint { - let j = 0u; - for a: ast::arg in args { if a.ident == i { ret j; } j += 1u; } - p.fatal("Unbound variable " + i + " in constraint arg"); -} - -fn parse_type_constr_arg(p: parser) -> @ast::ty_constr_arg { - let sp = p.span; - let carg = ast::carg_base; - expect(p, token::BINOP(token::STAR)); - if p.token == token::DOT { - // "*..." notation for record fields - p.bump(); - let pth = parse_path(p); - carg = ast::carg_ident(pth); - } - // No literals yet, I guess? - ret @{node: carg, span: sp}; -} - -fn parse_constr_arg(args: [ast::arg], p: parser) -> @ast::constr_arg { - let sp = p.span; - let carg = ast::carg_base; - if p.token == token::BINOP(token::STAR) { - p.bump(); - } else { - let i: ast::ident = parse_value_ident(p); - carg = ast::carg_ident(ident_index(p, args, i)); - } - ret @{node: carg, span: sp}; -} - -fn parse_ty_constr(fn_args: [ast::arg], p: parser) -> @ast::constr { - let lo = p.span.lo; - let path = parse_path(p); - let args: {node: [@ast::constr_arg], span: span} = - parse_seq(token::LPAREN, token::RPAREN, seq_sep(token::COMMA), - {|p| parse_constr_arg(fn_args, p)}, p); - ret @spanned(lo, args.span.hi, - {path: path, args: args.node, id: p.get_id()}); -} - -fn parse_constr_in_type(p: parser) -> @ast::ty_constr { - let lo = p.span.lo; - let path = parse_path(p); - let args: [@ast::ty_constr_arg] = - parse_seq(token::LPAREN, token::RPAREN, seq_sep(token::COMMA), - parse_type_constr_arg, p).node; - let hi = p.span.lo; - let tc: ast::ty_constr_ = {path: path, args: args, id: p.get_id()}; - ret @spanned(lo, hi, tc); -} - - -fn parse_constrs<T: copy>(pser: fn(parser) -> @ast::constr_general<T>, - p: parser) -> - [@ast::constr_general<T>] { - let constrs: [@ast::constr_general<T>] = []; - while true { - let constr = pser(p); - constrs += [constr]; - if p.token == token::COMMA { p.bump(); } else { break; } - } - constrs -} - -fn parse_type_constraints(p: parser) -> [@ast::ty_constr] { - ret parse_constrs(parse_constr_in_type, p); -} - -fn parse_ty_postfix(orig_t: ast::ty_, p: parser, colons_before_params: bool, - lo: uint) -> @ast::ty { - if colons_before_params && p.token == token::MOD_SEP { - p.bump(); - expect(p, token::LT); - } else if !colons_before_params && p.token == token::LT { - p.bump(); - } else { ret @spanned(lo, p.last_span.hi, orig_t); } - - // If we're here, we have explicit type parameter instantiation. - let seq = parse_seq_to_gt(some(token::COMMA), {|p| parse_ty(p, false)}, - p); - - alt orig_t { - ast::ty_path(pth, ann) { - ret @spanned(lo, p.last_span.hi, - ast::ty_path(@spanned(lo, p.last_span.hi, - {global: pth.node.global, - idents: pth.node.idents, - types: seq}), ann)); - } - _ { p.fatal("type parameter instantiation only allowed for paths"); } - } -} - -fn parse_ret_ty(p: parser) -> (ast::ret_style, @ast::ty) { - ret if eat(p, token::RARROW) { - let lo = p.span.lo; - if eat(p, token::NOT) { - (ast::noreturn, @spanned(lo, p.last_span.hi, ast::ty_bot)) - } else { (ast::return_val, parse_ty(p, false)) } - } else { - let pos = p.span.lo; - (ast::return_val, @spanned(pos, pos, ast::ty_nil)) - } -} - -fn parse_ty(p: parser, colons_before_params: bool) -> @ast::ty { - let lo = p.span.lo; - - alt have_dollar(p) { - some(e) {ret @spanned(lo, p.span.hi, - ast::ty_mac(spanned(lo, p.span.hi, e)))} - none {} - } - - let t = if p.token == token::LPAREN { - p.bump(); - if p.token == token::RPAREN { - p.bump(); - ast::ty_nil - } else { - let ts = [parse_ty(p, false)]; - while p.token == token::COMMA { - p.bump(); - ts += [parse_ty(p, false)]; - } - let t = if vec::len(ts) == 1u { ts[0].node } - else { ast::ty_tup(ts) }; - expect(p, token::RPAREN); - t - } - } else if p.token == token::AT { - p.bump(); - ast::ty_box(parse_mt(p)) - } else if p.token == token::TILDE { - p.bump(); - ast::ty_uniq(parse_mt(p)) - } else if p.token == token::BINOP(token::STAR) { - p.bump(); - ast::ty_ptr(parse_mt(p)) - } else if p.token == token::LBRACE { - let elems = - parse_seq(token::LBRACE, token::RBRACE, seq_sep_opt(token::COMMA), - parse_ty_field, p); - if vec::len(elems.node) == 0u { unexpected(p, token::RBRACE); } - let hi = elems.span.hi; - - let t = ast::ty_rec(elems.node); - if p.token == token::COLON { - p.bump(); - ast::ty_constr(@spanned(lo, hi, t), parse_type_constraints(p)) - } else { t } - } else if p.token == token::LBRACKET { - expect(p, token::LBRACKET); - let t = ast::ty_vec(parse_mt(p)); - expect(p, token::RBRACKET); - t - } else if eat_word(p, "fn") { - let proto = parse_fn_ty_proto(p); - alt proto { - ast::proto_bare { p.warn("fn is deprecated, use native fn"); } - _ { /* fallthrough */ } - } - ast::ty_fn(proto, parse_ty_fn(p)) - } else if eat_word(p, "native") { - expect_word(p, "fn"); - ast::ty_fn(ast::proto_bare, parse_ty_fn(p)) - } else if p.token == token::MOD_SEP || is_ident(p.token) { - let path = parse_path(p); - ast::ty_path(path, p.get_id()) - } else { p.fatal("expecting type"); }; - ret parse_ty_postfix(t, p, colons_before_params, lo); -} - -fn parse_arg_mode(p: parser) -> ast::mode { - if eat(p, token::BINOP(token::AND)) { - ast::expl(ast::by_mutbl_ref) - } else if eat(p, token::BINOP(token::MINUS)) { - ast::expl(ast::by_move) - } else if eat(p, token::ANDAND) { - ast::expl(ast::by_ref) - } else if eat(p, token::BINOP(token::PLUS)) { - if eat(p, token::BINOP(token::PLUS)) { - ast::expl(ast::by_val) - } else { - ast::expl(ast::by_copy) - } - } else { ast::infer(p.get_id()) } -} - -fn parse_arg(p: parser) -> ast::arg { - let m = parse_arg_mode(p); - let i = parse_value_ident(p); - expect(p, token::COLON); - let t = parse_ty(p, false); - ret {mode: m, ty: t, ident: i, id: p.get_id()}; -} - -fn parse_fn_block_arg(p: parser) -> ast::arg { - let m = parse_arg_mode(p); - let i = parse_value_ident(p); - let t = if eat(p, token::COLON) { - parse_ty(p, false) - } else { - @spanned(p.span.lo, p.span.hi, ast::ty_infer) - }; - ret {mode: m, ty: t, ident: i, id: p.get_id()}; -} - -fn parse_seq_to_before_gt<T: copy>(sep: option<token::token>, - f: fn(parser) -> T, - p: parser) -> [T] { - let first = true; - let v = []; - while p.token != token::GT && p.token != token::BINOP(token::LSR) && - p.token != token::BINOP(token::ASR) { - alt sep { - some(t) { if first { first = false; } else { expect(p, t); } } - _ { } - } - v += [f(p)]; - } - - ret v; -} - -fn parse_seq_to_gt<T: copy>(sep: option<token::token>, - f: fn(parser) -> T, p: parser) -> [T] { - let v = parse_seq_to_before_gt(sep, f, p); - expect_gt(p); - - ret v; -} - -fn parse_seq_lt_gt<T: copy>(sep: option<token::token>, - f: fn(parser) -> T, - p: parser) -> spanned<[T]> { - let lo = p.span.lo; - expect(p, token::LT); - let result = parse_seq_to_before_gt::<T>(sep, f, p); - let hi = p.span.hi; - expect_gt(p); - ret spanned(lo, hi, result); -} - -fn parse_seq_to_end<T: copy>(ket: token::token, sep: seq_sep, - f: fn(parser) -> T, p: parser) -> [T] { - let val = parse_seq_to_before_end(ket, sep, f, p); - p.bump(); - ret val; -} - -type seq_sep = { - sep: option<token::token>, - trailing_opt: bool // is trailing separator optional? -}; - -fn seq_sep(t: token::token) -> seq_sep { - ret {sep: option::some(t), trailing_opt: false}; -} -fn seq_sep_opt(t: token::token) -> seq_sep { - ret {sep: option::some(t), trailing_opt: true}; -} -fn seq_sep_none() -> seq_sep { - ret {sep: option::none, trailing_opt: false}; -} - -fn parse_seq_to_before_end<T: copy>(ket: token::token, - sep: seq_sep, - f: fn(parser) -> T, p: parser) -> [T] { - let first: bool = true; - let v: [T] = []; - while p.token != ket { - alt sep.sep { - some(t) { if first { first = false; } else { expect(p, t); } } - _ { } - } - if sep.trailing_opt && p.token == ket { break; } - v += [f(p)]; - } - ret v; -} - - -fn parse_seq<T: copy>(bra: token::token, ket: token::token, - sep: seq_sep, f: fn(parser) -> T, - p: parser) -> spanned<[T]> { - let lo = p.span.lo; - expect(p, bra); - let result = parse_seq_to_before_end::<T>(ket, sep, f, p); - let hi = p.span.hi; - p.bump(); - ret spanned(lo, hi, result); -} - -fn have_dollar(p: parser) -> option::t<ast::mac_> { - alt p.token { - token::DOLLAR_NUM(num) { - p.bump(); - some(ast::mac_var(num)) - } - token::DOLLAR_LPAREN { - let lo = p.span.lo; - p.bump(); - let e = parse_expr(p); - expect(p, token::RPAREN); - let hi = p.last_span.hi; - some(ast::mac_aq(ast_util::mk_sp(lo,hi), e)) - } - _ {none} - } -} - -fn lit_from_token(p: parser, tok: token::token) -> ast::lit_ { - alt tok { - token::LIT_INT(i, it) { ast::lit_int(i, it) } - token::LIT_UINT(u, ut) { ast::lit_uint(u, ut) } - token::LIT_FLOAT(s, ft) { ast::lit_float(p.get_str(s), ft) } - token::LIT_STR(s) { ast::lit_str(p.get_str(s)) } - token::LPAREN { expect(p, token::RPAREN); ast::lit_nil } - _ { unexpected(p, tok); } - } -} - -fn parse_lit(p: parser) -> ast::lit { - let sp = p.span; - let lit = if eat_word(p, "true") { - ast::lit_bool(true) - } else if eat_word(p, "false") { - ast::lit_bool(false) - } else { - let tok = p.token; - p.bump(); - lit_from_token(p, tok) - }; - ret {node: lit, span: sp}; -} - -fn is_ident(t: token::token) -> bool { - alt t { token::IDENT(_, _) { ret true; } _ { } } - ret false; -} - -fn is_plain_ident(p: parser) -> bool { - ret alt p.token { token::IDENT(_, false) { true } _ { false } }; -} - -fn parse_path(p: parser) -> @ast::path { - let lo = p.span.lo; - let global = eat(p, token::MOD_SEP), ids = [parse_ident(p)]; - while p.look_ahead(1u) != token::LT && eat(p, token::MOD_SEP) { - ids += [parse_ident(p)]; - } - ret @spanned(lo, p.last_span.hi, - {global: global, idents: ids, types: []}); -} - -fn parse_value_path(p: parser) -> @ast::path { - let pt = parse_path(p); - let last_word = pt.node.idents[vec::len(pt.node.idents)-1u]; - if p.bad_expr_words.contains_key(last_word) { - p.fatal("found " + last_word + " in expression position"); - } - pt -} - -fn parse_path_and_ty_param_substs(p: parser, colons: bool) -> @ast::path { - let lo = p.span.lo; - let path = parse_path(p); - let b = if colons { - eat(p, token::MOD_SEP) - } else { - p.token == token::LT - }; - if b { - let seq = parse_seq_lt_gt(some(token::COMMA), - {|p| parse_ty(p, false)}, p); - @spanned(lo, seq.span.hi, {types: seq.node with path.node}) - } else { path } -} - -fn parse_mutability(p: parser) -> ast::mutability { - if eat_word(p, "mutable") { - ast::m_mutbl - } else if eat_word(p, "mut") { - ast::m_mutbl - } else if eat_word(p, "const") { - ast::m_const - } else { - ast::m_imm - } -} - -fn parse_field(p: parser, sep: token::token) -> ast::field { - let lo = p.span.lo; - let m = parse_mutability(p); - let i = parse_ident(p); - expect(p, sep); - let e = parse_expr(p); - ret spanned(lo, e.span.hi, {mutbl: m, ident: i, expr: e}); -} - -fn mk_expr(p: parser, lo: uint, hi: uint, node: ast::expr_) -> @ast::expr { - ret @{id: p.get_id(), node: node, span: ast_util::mk_sp(lo, hi)}; -} - -fn mk_mac_expr(p: parser, lo: uint, hi: uint, m: ast::mac_) -> @ast::expr { - ret @{id: p.get_id(), - node: ast::expr_mac({node: m, span: ast_util::mk_sp(lo, hi)}), - span: ast_util::mk_sp(lo, hi)}; -} - -fn is_bar(t: token::token) -> bool { - alt t { token::BINOP(token::OR) | token::OROR { true } _ { false } } -} - -fn mk_lit_u32(p: parser, i: u32) -> @ast::expr { - let span = p.span; - let lv_lit = @{node: ast::lit_uint(i as u64, ast::ty_u32), - span: span}; - - ret @{id: p.get_id(), node: ast::expr_lit(lv_lit), span: span}; -} - -// We don't allow single-entry tuples in the true AST; that indicates a -// parenthesized expression. However, we preserve them temporarily while -// parsing because `(while{...})+3` parses differently from `while{...}+3`. -// -// To reflect the fact that the @ast::expr is not a true expr that should be -// part of the AST, we wrap such expressions in the pexpr enum. They -// can then be converted to true expressions by a call to `to_expr()`. -enum pexpr { - pexpr(@ast::expr), -} - -fn mk_pexpr(p: parser, lo: uint, hi: uint, node: ast::expr_) -> pexpr { - ret pexpr(mk_expr(p, lo, hi, node)); -} - -fn to_expr(e: pexpr) -> @ast::expr { - alt e.node { - ast::expr_tup(es) if vec::len(es) == 1u { es[0u] } - _ { *e } - } -} - -fn parse_bottom_expr(p: parser) -> pexpr { - let lo = p.span.lo; - let hi = p.span.hi; - - let ex: ast::expr_; - - alt have_dollar(p) { - some(x) {ret pexpr(mk_mac_expr(p, lo, p.span.hi, x));} - _ {} - } - - if p.token == token::LPAREN { - p.bump(); - if p.token == token::RPAREN { - hi = p.span.hi; - p.bump(); - let lit = @spanned(lo, hi, ast::lit_nil); - ret mk_pexpr(p, lo, hi, ast::expr_lit(lit)); - } - let es = [parse_expr(p)]; - while p.token == token::COMMA { p.bump(); es += [parse_expr(p)]; } - hi = p.span.hi; - expect(p, token::RPAREN); - - // Note: we retain the expr_tup() even for simple - // parenthesized expressions, but only for a "little while". - // This is so that wrappers around parse_bottom_expr() - // can tell whether the expression was parenthesized or not, - // which affects expr_is_complete(). - ret mk_pexpr(p, lo, hi, ast::expr_tup(es)); - } else if p.token == token::LBRACE { - p.bump(); - if is_word(p, "mut") || is_word(p, "mutable") || - is_plain_ident(p) && p.look_ahead(1u) == token::COLON { - let fields = [parse_field(p, token::COLON)]; - let base = none; - while p.token != token::RBRACE { - if eat_word(p, "with") { base = some(parse_expr(p)); break; } - expect(p, token::COMMA); - if p.token == token::RBRACE { - // record ends by an optional trailing comma - break; - } - fields += [parse_field(p, token::COLON)]; - } - hi = p.span.hi; - expect(p, token::RBRACE); - ex = ast::expr_rec(fields, base); - } else if is_bar(p.token) { - ret pexpr(parse_fn_block_expr(p)); - } else { - let blk = parse_block_tail(p, lo, ast::default_blk); - ret mk_pexpr(p, blk.span.lo, blk.span.hi, ast::expr_block(blk)); - } - } else if eat_word(p, "if") { - ret pexpr(parse_if_expr(p)); - } else if eat_word(p, "for") { - ret pexpr(parse_for_expr(p)); - } else if eat_word(p, "while") { - ret pexpr(parse_while_expr(p)); - } else if eat_word(p, "do") { - ret pexpr(parse_do_while_expr(p)); - } else if eat_word(p, "alt") { - ret pexpr(parse_alt_expr(p)); - } else if eat_word(p, "fn") { - let proto = parse_fn_ty_proto(p); - alt proto { - ast::proto_bare { p.fatal("fn expr are deprecated, use fn@"); } - ast::proto_any { p.fatal("fn* cannot be used in an expression"); } - _ { /* fallthrough */ } - } - ret pexpr(parse_fn_expr(p, proto)); - } else if eat_word(p, "unchecked") { - ret pexpr(parse_block_expr(p, lo, ast::unchecked_blk)); - } else if eat_word(p, "unsafe") { - ret pexpr(parse_block_expr(p, lo, ast::unsafe_blk)); - } else if p.token == token::LBRACKET { - p.bump(); - let mutbl = parse_mutability(p); - let es = - parse_seq_to_end(token::RBRACKET, seq_sep(token::COMMA), - parse_expr, p); - ex = ast::expr_vec(es, mutbl); - } else if p.token == token::POUND_LT { - p.bump(); - let ty = parse_ty(p, false); - expect(p, token::GT); - - /* hack: early return to take advantage of specialized function */ - ret pexpr(mk_mac_expr(p, lo, p.span.hi, - ast::mac_embed_type(ty))); - } else if p.token == token::POUND_LBRACE { - p.bump(); - let blk = ast::mac_embed_block( - parse_block_tail(p, lo, ast::default_blk)); - ret pexpr(mk_mac_expr(p, lo, p.span.hi, blk)); - } else if p.token == token::ELLIPSIS { - p.bump(); - ret pexpr(mk_mac_expr(p, lo, p.span.hi, ast::mac_ellipsis)); - } else if eat_word(p, "bind") { - let e = parse_expr_res(p, RESTRICT_NO_CALL_EXPRS); - let es = - parse_seq(token::LPAREN, token::RPAREN, seq_sep(token::COMMA), - parse_expr_or_hole, p); - hi = es.span.hi; - ex = ast::expr_bind(e, es.node); - } else if p.token == token::POUND { - let ex_ext = parse_syntax_ext(p); - hi = ex_ext.span.hi; - ex = ex_ext.node; - } else if eat_word(p, "fail") { - if can_begin_expr(p.token) { - let e = parse_expr(p); - hi = e.span.hi; - ex = ast::expr_fail(some(e)); - } else { ex = ast::expr_fail(none); } - } else if eat_word(p, "log") { - expect(p, token::LPAREN); - let lvl = parse_expr(p); - expect(p, token::COMMA); - let e = parse_expr(p); - ex = ast::expr_log(2, lvl, e); - hi = p.span.hi; - expect(p, token::RPAREN); - } else if eat_word(p, "assert") { - let e = parse_expr(p); - ex = ast::expr_assert(e); - hi = e.span.hi; - } else if eat_word(p, "check") { - /* Should be a predicate (pure boolean function) applied to - arguments that are all either slot variables or literals. - but the typechecker enforces that. */ - let e = parse_expr(p); - hi = e.span.hi; - ex = ast::expr_check(ast::checked_expr, e); - } else if eat_word(p, "claim") { - /* Same rules as check, except that if check-claims - is enabled (a command-line flag), then the parser turns - claims into check */ - - let e = parse_expr(p); - hi = e.span.hi; - ex = ast::expr_check(ast::claimed_expr, e); - } else if eat_word(p, "ret") { - if can_begin_expr(p.token) { - let e = parse_expr(p); - hi = e.span.hi; - ex = ast::expr_ret(some(e)); - } else { ex = ast::expr_ret(none); } - } else if eat_word(p, "break") { - ex = ast::expr_break; - hi = p.span.hi; - } else if eat_word(p, "cont") { - ex = ast::expr_cont; - hi = p.span.hi; - } else if eat_word(p, "be") { - let e = parse_expr(p); - - // FIXME: Is this the right place for this check? - if /*check*/ast_util::is_call_expr(e) { - hi = e.span.hi; - ex = ast::expr_be(e); - } else { p.fatal("Non-call expression in tail call"); } - } else if eat_word(p, "copy") { - let e = parse_expr(p); - ex = ast::expr_copy(e); - hi = e.span.hi; - } else if p.token == token::MOD_SEP || - is_ident(p.token) && !is_word(p, "true") && - !is_word(p, "false") { - check_bad_word(p); - let pth = parse_path_and_ty_param_substs(p, true); - hi = pth.span.hi; - ex = ast::expr_path(pth); - } else { - let lit = parse_lit(p); - hi = lit.span.hi; - ex = ast::expr_lit(@lit); - } - ret mk_pexpr(p, lo, hi, ex); -} - -fn parse_block_expr(p: parser, - lo: uint, - blk_mode: ast::blk_check_mode) -> @ast::expr { - expect(p, token::LBRACE); - let blk = parse_block_tail(p, lo, blk_mode); - ret mk_expr(p, blk.span.lo, blk.span.hi, ast::expr_block(blk)); -} - -fn parse_syntax_ext(p: parser) -> @ast::expr { - let lo = p.span.lo; - expect(p, token::POUND); - ret parse_syntax_ext_naked(p, lo); -} - -fn parse_syntax_ext_naked(p: parser, lo: uint) -> @ast::expr { - alt p.token { - token::IDENT(_, _) {} - _ { p.fatal("expected a syntax expander name"); } - } - let pth = parse_path(p); - //temporary for a backwards-compatible cycle: - let sep = seq_sep(token::COMMA); - let e = none; - if (p.token == token::LPAREN || p.token == token::LBRACKET) { - let es = - if p.token == token::LPAREN { - parse_seq(token::LPAREN, token::RPAREN, - sep, parse_expr, p) - } else { - parse_seq(token::LBRACKET, token::RBRACKET, - sep, parse_expr, p) - }; - let hi = es.span.hi; - e = some(mk_expr(p, es.span.lo, hi, - ast::expr_vec(es.node, ast::m_imm))); - } - let b = none; - if p.token == token::LBRACE { - p.bump(); - let lo = p.span.lo; - let depth = 1u; - while (depth > 0u) { - alt (p.token) { - token::LBRACE {depth += 1u;} - token::RBRACE {depth -= 1u;} - token::EOF {p.fatal("unexpected EOF in macro body");} - _ {} - } - p.bump(); - } - let hi = p.last_span.lo; - b = some({span: mk_sp(lo,hi)}); - } - ret mk_mac_expr(p, lo, p.span.hi, ast::mac_invoc(pth, e, b)); -} - -fn parse_dot_or_call_expr(p: parser) -> pexpr { - let b = parse_bottom_expr(p); - parse_dot_or_call_expr_with(p, b) -} - -fn permits_call(p: parser) -> bool { - ret p.restriction != RESTRICT_NO_CALL_EXPRS; -} - -fn parse_dot_or_call_expr_with(p: parser, e0: pexpr) -> pexpr { - let e = e0; - let lo = e.span.lo; - let hi = e.span.hi; - while true { - // expr.f - if eat(p, token::DOT) { - alt p.token { - token::IDENT(i, _) { - hi = p.span.hi; - p.bump(); - let tys = if eat(p, token::MOD_SEP) { - expect(p, token::LT); - parse_seq_to_gt(some(token::COMMA), - {|p| parse_ty(p, false)}, p) - } else { [] }; - e = mk_pexpr(p, lo, hi, - ast::expr_field(to_expr(e), - p.get_str(i), - tys)); - } - t { unexpected(p, t); } - } - cont; - } - if expr_is_complete(p, e) { break; } - alt p.token { - // expr(...) - token::LPAREN if permits_call(p) { - let es_opt = - parse_seq(token::LPAREN, token::RPAREN, - seq_sep(token::COMMA), parse_expr_or_hole, p); - hi = es_opt.span.hi; - - let nd = - if vec::any(es_opt.node, {|e| option::is_none(e) }) { - ast::expr_bind(to_expr(e), es_opt.node) - } else { - let es = vec::map(es_opt.node) {|e| option::get(e) }; - ast::expr_call(to_expr(e), es, false) - }; - e = mk_pexpr(p, lo, hi, nd); - } - - // expr {|| ... } - token::LBRACE if is_bar(p.look_ahead(1u)) && permits_call(p) { - p.bump(); - let blk = parse_fn_block_expr(p); - alt e.node { - ast::expr_call(f, args, false) { - e = pexpr(@{node: ast::expr_call(f, args + [blk], true) - with *to_expr(e)}); - } - _ { - e = mk_pexpr(p, lo, p.last_span.hi, - ast::expr_call(to_expr(e), [blk], true)); - } - } - } - - // expr[...] - token::LBRACKET { - p.bump(); - let ix = parse_expr(p); - hi = ix.span.hi; - expect(p, token::RBRACKET); - p.get_id(); // see ast_util::op_expr_callee_id - e = mk_pexpr(p, lo, hi, ast::expr_index(to_expr(e), ix)); - } - - _ { ret e; } - } - } - ret e; -} - -fn parse_prefix_expr(p: parser) -> pexpr { - let lo = p.span.lo; - let hi = p.span.hi; - - let ex; - alt p.token { - token::NOT { - p.bump(); - let e = to_expr(parse_prefix_expr(p)); - hi = e.span.hi; - p.get_id(); // see ast_util::op_expr_callee_id - ex = ast::expr_unary(ast::not, e); - } - token::BINOP(b) { - alt b { - token::MINUS { - p.bump(); - let e = to_expr(parse_prefix_expr(p)); - hi = e.span.hi; - p.get_id(); // see ast_util::op_expr_callee_id - ex = ast::expr_unary(ast::neg, e); - } - token::STAR { - p.bump(); - let e = to_expr(parse_prefix_expr(p)); - hi = e.span.hi; - ex = ast::expr_unary(ast::deref, e); - } - _ { ret parse_dot_or_call_expr(p); } - } - } - token::AT { - p.bump(); - let m = parse_mutability(p); - let e = to_expr(parse_prefix_expr(p)); - hi = e.span.hi; - ex = ast::expr_unary(ast::box(m), e); - } - token::TILDE { - p.bump(); - let m = parse_mutability(p); - let e = to_expr(parse_prefix_expr(p)); - hi = e.span.hi; - ex = ast::expr_unary(ast::uniq(m), e); - } - _ { ret parse_dot_or_call_expr(p); } - } - ret mk_pexpr(p, lo, hi, ex); -} - -type op_spec = {tok: token::token, op: ast::binop, prec: int}; - - -// FIXME make this a const, don't store it in parser state -fn prec_table() -> @[op_spec] { - ret @[// 'as' sits between here with 12 - {tok: token::BINOP(token::STAR), op: ast::mul, prec: 11}, - {tok: token::BINOP(token::SLASH), op: ast::div, prec: 11}, - {tok: token::BINOP(token::PERCENT), op: ast::rem, prec: 11}, - {tok: token::BINOP(token::PLUS), op: ast::add, prec: 10}, - {tok: token::BINOP(token::MINUS), op: ast::subtract, prec: 10}, - {tok: token::BINOP(token::LSL), op: ast::lsl, prec: 9}, - {tok: token::BINOP(token::LSR), op: ast::lsr, prec: 9}, - {tok: token::BINOP(token::ASR), op: ast::asr, prec: 9}, - {tok: token::BINOP(token::AND), op: ast::bitand, prec: 8}, - {tok: token::BINOP(token::CARET), op: ast::bitxor, prec: 7}, - {tok: token::BINOP(token::OR), op: ast::bitor, prec: 6}, - {tok: token::LT, op: ast::lt, prec: 4}, - {tok: token::LE, op: ast::le, prec: 4}, - {tok: token::GE, op: ast::ge, prec: 4}, - {tok: token::GT, op: ast::gt, prec: 4}, - {tok: token::EQEQ, op: ast::eq, prec: 3}, - {tok: token::NE, op: ast::ne, prec: 3}, - {tok: token::ANDAND, op: ast::and, prec: 2}, - {tok: token::OROR, op: ast::or, prec: 1}]; -} - -fn parse_binops(p: parser) -> @ast::expr { - ret parse_more_binops(p, parse_prefix_expr(p), 0); -} - -const unop_prec: int = 100; - -const as_prec: int = 12; - -fn parse_more_binops(p: parser, plhs: pexpr, min_prec: int) -> - @ast::expr { - let lhs = to_expr(plhs); - if expr_is_complete(p, plhs) { ret lhs; } - let peeked = p.token; - if peeked == token::BINOP(token::OR) && - p.restriction == RESTRICT_NO_BAR_OP { ret lhs; } - for cur: op_spec in *p.precs { - if cur.prec > min_prec && cur.tok == peeked { - p.bump(); - let expr = parse_prefix_expr(p); - let rhs = parse_more_binops(p, expr, cur.prec); - p.get_id(); // see ast_util::op_expr_callee_id - let bin = mk_pexpr(p, lhs.span.lo, rhs.span.hi, - ast::expr_binary(cur.op, lhs, rhs)); - ret parse_more_binops(p, bin, min_prec); - } - } - if as_prec > min_prec && eat_word(p, "as") { - let rhs = parse_ty(p, true); - let _as = - mk_pexpr(p, lhs.span.lo, rhs.span.hi, ast::expr_cast(lhs, rhs)); - ret parse_more_binops(p, _as, min_prec); - } - ret lhs; -} - -fn parse_assign_expr(p: parser) -> @ast::expr { - let lo = p.span.lo; - let lhs = parse_binops(p); - alt p.token { - token::EQ { - p.bump(); - let rhs = parse_expr(p); - ret mk_expr(p, lo, rhs.span.hi, ast::expr_assign(lhs, rhs)); - } - token::BINOPEQ(op) { - p.bump(); - let rhs = parse_expr(p); - let aop = ast::add; - alt op { - token::PLUS { aop = ast::add; } - token::MINUS { aop = ast::subtract; } - token::STAR { aop = ast::mul; } - token::SLASH { aop = ast::div; } - token::PERCENT { aop = ast::rem; } - token::CARET { aop = ast::bitxor; } - token::AND { aop = ast::bitand; } - token::OR { aop = ast::bitor; } - token::LSL { aop = ast::lsl; } - token::LSR { aop = ast::lsr; } - token::ASR { aop = ast::asr; } - } - p.get_id(); // see ast_util::op_expr_callee_id - ret mk_expr(p, lo, rhs.span.hi, ast::expr_assign_op(aop, lhs, rhs)); - } - token::LARROW { - p.bump(); - let rhs = parse_expr(p); - ret mk_expr(p, lo, rhs.span.hi, ast::expr_move(lhs, rhs)); - } - token::DARROW { - p.bump(); - let rhs = parse_expr(p); - ret mk_expr(p, lo, rhs.span.hi, ast::expr_swap(lhs, rhs)); - } - _ {/* fall through */ } - } - ret lhs; -} - -fn parse_if_expr_1(p: parser) -> - {cond: @ast::expr, - then: ast::blk, - els: option<@ast::expr>, - lo: uint, - hi: uint} { - let lo = p.last_span.lo; - let cond = parse_expr(p); - let thn = parse_block(p); - let els: option<@ast::expr> = none; - let hi = thn.span.hi; - if eat_word(p, "else") { - let elexpr = parse_else_expr(p); - els = some(elexpr); - hi = elexpr.span.hi; - } - ret {cond: cond, then: thn, els: els, lo: lo, hi: hi}; -} - -fn parse_if_expr(p: parser) -> @ast::expr { - if eat_word(p, "check") { - let q = parse_if_expr_1(p); - ret mk_expr(p, q.lo, q.hi, ast::expr_if_check(q.cond, q.then, q.els)); - } else { - let q = parse_if_expr_1(p); - ret mk_expr(p, q.lo, q.hi, ast::expr_if(q.cond, q.then, q.els)); - } -} - -// Parses: -// -// CC := [copy ID*; move ID*] -// -// where any part is optional and trailing ; is permitted. -fn parse_capture_clause(p: parser) -> @ast::capture_clause { - fn expect_opt_trailing_semi(p: parser) { - if !eat(p, token::SEMI) { - if p.token != token::RBRACKET { - p.fatal("expecting ; or ]"); - } - } - } - - fn eat_ident_list(p: parser) -> [@ast::capture_item] { - let res = []; - while true { - alt p.token { - token::IDENT(_, _) { - let id = p.get_id(); - let sp = ast_util::mk_sp(p.span.lo, p.span.hi); - let ident = parse_ident(p); - res += [@{id:id, name:ident, span:sp}]; - if !eat(p, token::COMMA) { - ret res; - } - } - - _ { ret res; } - } - } - std::util::unreachable(); - } - - let copies = []; - let moves = []; - - if eat(p, token::LBRACKET) { - while !eat(p, token::RBRACKET) { - if eat_word(p, "copy") { - copies += eat_ident_list(p); - expect_opt_trailing_semi(p); - } else if eat_word(p, "move") { - moves += eat_ident_list(p); - expect_opt_trailing_semi(p); - } else { - let s: str = "expecting send, copy, or move clause"; - p.fatal(s); - } - } - } - - ret @{copies: copies, moves: moves}; -} - -fn parse_fn_expr(p: parser, proto: ast::proto) -> @ast::expr { - let lo = p.last_span.lo; - let capture_clause = parse_capture_clause(p); - let decl = parse_fn_decl(p, ast::impure_fn); - let body = parse_block(p); - ret mk_expr(p, lo, body.span.hi, - ast::expr_fn(proto, decl, body, capture_clause)); -} - -fn parse_fn_block_expr(p: parser) -> @ast::expr { - let lo = p.last_span.lo; - let decl = parse_fn_block_decl(p); - let body = parse_block_tail(p, lo, ast::default_blk); - ret mk_expr(p, lo, body.span.hi, ast::expr_fn_block(decl, body)); -} - -fn parse_else_expr(p: parser) -> @ast::expr { - if eat_word(p, "if") { - ret parse_if_expr(p); - } else { - let blk = parse_block(p); - ret mk_expr(p, blk.span.lo, blk.span.hi, ast::expr_block(blk)); - } -} - -fn parse_for_expr(p: parser) -> @ast::expr { - let lo = p.last_span.lo; - let decl = parse_local(p, false, false); - expect_word(p, "in"); - let seq = parse_expr(p); - let body = parse_block_no_value(p); - let hi = body.span.hi; - ret mk_expr(p, lo, hi, ast::expr_for(decl, seq, body)); -} - -fn parse_while_expr(p: parser) -> @ast::expr { - let lo = p.last_span.lo; - let cond = parse_expr(p); - let body = parse_block_no_value(p); - let hi = body.span.hi; - ret mk_expr(p, lo, hi, ast::expr_while(cond, body)); -} - -fn parse_do_while_expr(p: parser) -> @ast::expr { - let lo = p.last_span.lo; - let body = parse_block_no_value(p); - expect_word(p, "while"); - let cond = parse_expr(p); - let hi = cond.span.hi; - ret mk_expr(p, lo, hi, ast::expr_do_while(body, cond)); -} - -fn parse_alt_expr(p: parser) -> @ast::expr { - let lo = p.last_span.lo; - let mode = if eat_word(p, "check") { ast::alt_check } - else { ast::alt_exhaustive }; - let discriminant = parse_expr(p); - expect(p, token::LBRACE); - let arms: [ast::arm] = []; - while p.token != token::RBRACE { - let pats = parse_pats(p); - let guard = none; - if eat_word(p, "if") { guard = some(parse_expr(p)); } - let blk = parse_block(p); - arms += [{pats: pats, guard: guard, body: blk}]; - } - let hi = p.span.hi; - p.bump(); - ret mk_expr(p, lo, hi, ast::expr_alt(discriminant, arms, mode)); -} - -fn parse_expr(p: parser) -> @ast::expr { - ret parse_expr_res(p, UNRESTRICTED); -} - -fn parse_expr_or_hole(p: parser) -> option<@ast::expr> { - alt p.token { - token::UNDERSCORE { p.bump(); ret none; } - _ { ret some(parse_expr(p)); } - } -} - -fn parse_expr_res(p: parser, r: restriction) -> @ast::expr { - let old = p.restriction; - p.restriction = r; - let e = parse_assign_expr(p); - p.restriction = old; - ret e; -} - -fn parse_initializer(p: parser) -> option<ast::initializer> { - alt p.token { - token::EQ { - p.bump(); - ret some({op: ast::init_assign, expr: parse_expr(p)}); - } - token::LARROW { - p.bump(); - ret some({op: ast::init_move, expr: parse_expr(p)}); - } - // Now that the the channel is the first argument to receive, - // combining it with an initializer doesn't really make sense. - // case (token::RECV) { - // p.bump(); - // ret some(rec(op = ast::init_recv, - // expr = parse_expr(p))); - // } - _ { - ret none; - } - } -} - -fn parse_pats(p: parser) -> [@ast::pat] { - let pats = []; - while true { - pats += [parse_pat(p)]; - if p.token == token::BINOP(token::OR) { p.bump(); } else { break; } - } - ret pats; -} - -fn parse_pat(p: parser) -> @ast::pat { - let lo = p.span.lo; - let hi = p.span.hi; - let pat; - alt p.token { - token::UNDERSCORE { p.bump(); pat = ast::pat_wild; } - token::AT { - p.bump(); - let sub = parse_pat(p); - pat = ast::pat_box(sub); - hi = sub.span.hi; - } - token::TILDE { - p.bump(); - let sub = parse_pat(p); - pat = ast::pat_uniq(sub); - hi = sub.span.hi; - } - token::LBRACE { - p.bump(); - let fields = []; - let etc = false; - let first = true; - while p.token != token::RBRACE { - if first { first = false; } else { expect(p, token::COMMA); } - - if p.token == token::UNDERSCORE { - p.bump(); - if p.token != token::RBRACE { - p.fatal("expecting }, found " + - token::to_str(p.reader, p.token)); - } - etc = true; - break; - } - - let lo1 = p.last_span.lo; - let fieldname = parse_ident(p); - let hi1 = p.last_span.lo; - let fieldpath = ast_util::ident_to_path(ast_util::mk_sp(lo1, hi1), - fieldname); - let subpat; - if p.token == token::COLON { - p.bump(); - subpat = parse_pat(p); - } else { - if p.bad_expr_words.contains_key(fieldname) { - p.fatal("found " + fieldname + " in binding position"); - } - subpat = @{id: p.get_id(), - node: ast::pat_ident(fieldpath, none), - span: ast_util::mk_sp(lo, hi)}; - } - fields += [{ident: fieldname, pat: subpat}]; - } - hi = p.span.hi; - p.bump(); - pat = ast::pat_rec(fields, etc); - } - token::LPAREN { - p.bump(); - if p.token == token::RPAREN { - hi = p.span.hi; - p.bump(); - let lit = @{node: ast::lit_nil, span: ast_util::mk_sp(lo, hi)}; - let expr = mk_expr(p, lo, hi, ast::expr_lit(lit)); - pat = ast::pat_lit(expr); - } else { - let fields = [parse_pat(p)]; - while p.token == token::COMMA { - p.bump(); - fields += [parse_pat(p)]; - } - if vec::len(fields) == 1u { expect(p, token::COMMA); } - hi = p.span.hi; - expect(p, token::RPAREN); - pat = ast::pat_tup(fields); - } - } - tok { - if !is_ident(tok) || is_word(p, "true") || is_word(p, "false") { - let val = parse_expr_res(p, RESTRICT_NO_BAR_OP); - if eat_word(p, "to") { - let end = parse_expr_res(p, RESTRICT_NO_BAR_OP); - hi = end.span.hi; - pat = ast::pat_range(val, end); - } else { - hi = val.span.hi; - pat = ast::pat_lit(val); - } - } else if is_plain_ident(p) && - alt p.look_ahead(1u) { - token::LPAREN | token::LBRACKET | token::LT { false } - _ { true } - } { - let name = parse_value_path(p); - let sub = if eat(p, token::AT) { some(parse_pat(p)) } - else { none }; - pat = ast::pat_ident(name, sub); - } else { - let enum_path = parse_path_and_ty_param_substs(p, true); - hi = enum_path.span.hi; - let args: [@ast::pat]; - alt p.token { - token::LPAREN { - let a = - parse_seq(token::LPAREN, token::RPAREN, - seq_sep(token::COMMA), parse_pat, p); - args = a.node; - hi = a.span.hi; - } - _ { args = []; } - } - // at this point, we're not sure whether it's a enum or a bind - if vec::len(args) == 0u && - vec::len(enum_path.node.idents) == 1u { - pat = ast::pat_ident(enum_path, none); - } - else { - pat = ast::pat_enum(enum_path, args); - } - } - } - } - ret @{id: p.get_id(), node: pat, span: ast_util::mk_sp(lo, hi)}; -} - -fn parse_local(p: parser, is_mutbl: bool, - allow_init: bool) -> @ast::local { - let lo = p.span.lo; - let pat = parse_pat(p); - let ty = @spanned(lo, lo, ast::ty_infer); - if eat(p, token::COLON) { ty = parse_ty(p, false); } - let init = if allow_init { parse_initializer(p) } else { none }; - ret @spanned(lo, p.last_span.hi, - {is_mutbl: is_mutbl, ty: ty, pat: pat, - init: init, id: p.get_id()}); -} - -fn parse_let(p: parser) -> @ast::decl { - let is_mutbl = eat_word(p, "mut"); - let lo = p.span.lo; - let locals = [parse_local(p, is_mutbl, true)]; - while eat(p, token::COMMA) { - locals += [parse_local(p, is_mutbl, true)]; - } - ret @spanned(lo, p.last_span.hi, ast::decl_local(locals)); -} - -fn parse_instance_var(p:parser) -> ast::class_member { - let is_mutbl = ast::class_immutable; - expect_word(p, "let"); - if eat_word(p, "mut") || eat_word(p, "mutable") { - is_mutbl = ast::class_mutable; - } - if !is_plain_ident(p) { - p.fatal("expecting ident"); - } - let name = parse_ident(p); - expect(p, token::COLON); - let ty = parse_ty(p, false); - ret ast::instance_var(name, ty, is_mutbl, p.get_id()); -} - -fn parse_stmt(p: parser, first_item_attrs: [ast::attribute]) -> @ast::stmt { - fn check_expected_item(p: parser, current_attrs: [ast::attribute]) { - // If we have attributes then we should have an item - if vec::is_not_empty(current_attrs) { - p.fatal("expected item"); - } - } - - let lo = p.span.lo; - if is_word(p, "let") { - check_expected_item(p, first_item_attrs); - expect_word(p, "let"); - let decl = parse_let(p); - ret @spanned(lo, decl.span.hi, ast::stmt_decl(decl, p.get_id())); - } else { - let item_attrs; - alt parse_outer_attrs_or_ext(p, first_item_attrs) { - none { item_attrs = []; } - some(left(attrs)) { item_attrs = attrs; } - some(right(ext)) { - ret @spanned(lo, ext.span.hi, ast::stmt_expr(ext, p.get_id())); - } - } - - let item_attrs = first_item_attrs + item_attrs; - - alt parse_item(p, item_attrs) { - some(i) { - let hi = i.span.hi; - let decl = @spanned(lo, hi, ast::decl_item(i)); - ret @spanned(lo, hi, ast::stmt_decl(decl, p.get_id())); - } - none() { /* fallthrough */ } - } - - check_expected_item(p, item_attrs); - - // Remainder are line-expr stmts. - let e = parse_expr_res(p, RESTRICT_STMT_EXPR); - ret @spanned(lo, e.span.hi, ast::stmt_expr(e, p.get_id())); - } -} - -fn expr_is_complete(p: parser, e: pexpr) -> bool { - log(debug, ("expr_is_complete", p.restriction, - print::pprust::expr_to_str(*e), - expr_requires_semi_to_be_stmt(*e))); - ret p.restriction == RESTRICT_STMT_EXPR && - !expr_requires_semi_to_be_stmt(*e); -} - -fn expr_requires_semi_to_be_stmt(e: @ast::expr) -> bool { - alt e.node { - ast::expr_if(_, _, _) | ast::expr_if_check(_, _, _) - | ast::expr_alt(_, _, _) | ast::expr_block(_) - | ast::expr_do_while(_, _) | ast::expr_while(_, _) - | ast::expr_for(_, _, _) - | ast::expr_call(_, _, true) { - false - } - _ { true } - } -} - -fn stmt_ends_with_semi(stmt: ast::stmt) -> bool { - alt stmt.node { - ast::stmt_decl(d, _) { - ret alt d.node { - ast::decl_local(_) { true } - ast::decl_item(_) { false } - } - } - ast::stmt_expr(e, _) { - ret expr_requires_semi_to_be_stmt(e); - } - ast::stmt_semi(e, _) { - ret false; - } - } -} - -fn parse_block(p: parser) -> ast::blk { - let (attrs, blk) = parse_inner_attrs_and_block(p, false); - assert vec::is_empty(attrs); - ret blk; -} - -fn parse_inner_attrs_and_block( - p: parser, parse_attrs: bool) -> ([ast::attribute], ast::blk) { - - fn maybe_parse_inner_attrs_and_next( - p: parser, parse_attrs: bool) -> - {inner: [ast::attribute], next: [ast::attribute]} { - if parse_attrs { - parse_inner_attrs_and_next(p) - } else { - {inner: [], next: []} - } - } - - let lo = p.span.lo; - if eat_word(p, "unchecked") { - expect(p, token::LBRACE); - let {inner, next} = maybe_parse_inner_attrs_and_next(p, parse_attrs); - ret (inner, parse_block_tail_(p, lo, ast::unchecked_blk, next)); - } else if eat_word(p, "unsafe") { - expect(p, token::LBRACE); - let {inner, next} = maybe_parse_inner_attrs_and_next(p, parse_attrs); - ret (inner, parse_block_tail_(p, lo, ast::unsafe_blk, next)); - } else { - expect(p, token::LBRACE); - let {inner, next} = maybe_parse_inner_attrs_and_next(p, parse_attrs); - ret (inner, parse_block_tail_(p, lo, ast::default_blk, next)); - } -} - -fn parse_block_no_value(p: parser) -> ast::blk { - // We parse blocks that cannot have a value the same as any other block; - // the type checker will make sure that the tail expression (if any) has - // unit type. - ret parse_block(p); -} - -// Precondition: already parsed the '{' or '#{' -// I guess that also means "already parsed the 'impure'" if -// necessary, and this should take a qualifier. -// some blocks start with "#{"... -fn parse_block_tail(p: parser, lo: uint, s: ast::blk_check_mode) -> ast::blk { - parse_block_tail_(p, lo, s, []) -} - -fn parse_block_tail_(p: parser, lo: uint, s: ast::blk_check_mode, - first_item_attrs: [ast::attribute]) -> ast::blk { - let stmts = []; - let expr = none; - let view_items = maybe_parse_view_import_only(p, first_item_attrs); - let initial_attrs = first_item_attrs; - - if p.token == token::RBRACE && !vec::is_empty(initial_attrs) { - p.fatal("expected item"); - } - - while p.token != token::RBRACE { - alt p.token { - token::SEMI { - p.bump(); // empty - } - _ { - let stmt = parse_stmt(p, initial_attrs); - initial_attrs = []; - alt stmt.node { - ast::stmt_expr(e, stmt_id) { // Expression without semicolon: - alt p.token { - token::SEMI { - p.bump(); - stmts += [@{node: ast::stmt_semi(e, stmt_id) with *stmt}]; - } - token::RBRACE { - expr = some(e); - } - t { - if stmt_ends_with_semi(*stmt) { - p.fatal("expected ';' or '}' after expression but \ - found '" + token::to_str(p.reader, t) + - "'"); - } - stmts += [stmt]; - } - } - } - - _ { // All other kinds of statements: - stmts += [stmt]; - - if stmt_ends_with_semi(*stmt) { - expect(p, token::SEMI); - } - } - } - } - } - } - let hi = p.span.hi; - p.bump(); - let bloc = {view_items: view_items, stmts: stmts, expr: expr, - id: p.get_id(), rules: s}; - ret spanned(lo, hi, bloc); -} - -fn parse_ty_param(p: parser) -> ast::ty_param { - let bounds = []; - let ident = parse_ident(p); - if eat(p, token::COLON) { - while p.token != token::COMMA && p.token != token::GT { - if eat_word(p, "send") { bounds += [ast::bound_send]; } - else if eat_word(p, "copy") { bounds += [ast::bound_copy]; } - else { bounds += [ast::bound_iface(parse_ty(p, false))]; } - } - } - ret {ident: ident, id: p.get_id(), bounds: @bounds}; -} - -fn parse_ty_params(p: parser) -> [ast::ty_param] { - if eat(p, token::LT) { - parse_seq_to_gt(some(token::COMMA), parse_ty_param, p) - } else { [] } -} - -fn parse_fn_decl(p: parser, purity: ast::purity) - -> ast::fn_decl { - let inputs: ast::spanned<[ast::arg]> = - parse_seq(token::LPAREN, token::RPAREN, seq_sep(token::COMMA), - parse_arg, p); - // Use the args list to translate each bound variable - // mentioned in a constraint to an arg index. - // Seems weird to do this in the parser, but I'm not sure how else to. - let constrs = []; - if p.token == token::COLON { - p.bump(); - constrs = parse_constrs({|x| parse_ty_constr(inputs.node, x) }, p); - } - let (ret_style, ret_ty) = parse_ret_ty(p); - ret {inputs: inputs.node, - output: ret_ty, - purity: purity, - cf: ret_style, - constraints: constrs}; -} - -fn parse_fn_block_decl(p: parser) -> ast::fn_decl { - let inputs = if eat(p, token::OROR) { - [] - } else { - parse_seq(token::BINOP(token::OR), - token::BINOP(token::OR), - seq_sep(token::COMMA), - parse_fn_block_arg, p).node - }; - let output = if eat(p, token::RARROW) { - parse_ty(p, false) - } else { - @spanned(p.span.lo, p.span.hi, ast::ty_infer) - }; - ret {inputs: inputs, - output: output, - purity: ast::impure_fn, - cf: ast::return_val, - constraints: []}; -} - -fn parse_fn_header(p: parser) -> {ident: ast::ident, tps: [ast::ty_param]} { - let id = parse_value_ident(p); - let ty_params = parse_ty_params(p); - ret {ident: id, tps: ty_params}; -} - -fn mk_item(p: parser, lo: uint, hi: uint, ident: ast::ident, node: ast::item_, - attrs: [ast::attribute]) -> @ast::item { - ret @{ident: ident, - attrs: attrs, - id: p.get_id(), - node: node, - span: ast_util::mk_sp(lo, hi)}; -} - -fn parse_item_fn(p: parser, purity: ast::purity, - attrs: [ast::attribute]) -> @ast::item { - let lo = p.last_span.lo; - let t = parse_fn_header(p); - let decl = parse_fn_decl(p, purity); - let (inner_attrs, body) = parse_inner_attrs_and_block(p, true); - let attrs = attrs + inner_attrs; - ret mk_item(p, lo, body.span.hi, t.ident, - ast::item_fn(decl, t.tps, body), attrs); -} - -fn parse_method_name(p: parser) -> ast::ident { - alt p.token { - token::BINOP(op) { p.bump(); token::binop_to_str(op) } - token::NOT { p.bump(); "!" } - token::LBRACKET { p.bump(); expect(p, token::RBRACKET); "[]" } - _ { - let id = parse_value_ident(p); - if id == "unary" && eat(p, token::BINOP(token::MINUS)) { "unary-" } - else { id } - } - } -} - -fn parse_method(p: parser) -> @ast::method { - let attrs = parse_outer_attributes(p); - let lo = p.span.lo, pur = parse_fn_purity(p); - let ident = parse_method_name(p); - let tps = parse_ty_params(p); - let decl = parse_fn_decl(p, pur); - let (inner_attrs, body) = parse_inner_attrs_and_block(p, true); - let attrs = attrs + inner_attrs; - @{ident: ident, attrs: attrs, tps: tps, decl: decl, body: body, - id: p.get_id(), span: ast_util::mk_sp(lo, body.span.hi)} -} - -fn parse_item_iface(p: parser, attrs: [ast::attribute]) -> @ast::item { - let lo = p.last_span.lo, ident = parse_ident(p), - tps = parse_ty_params(p), meths = parse_ty_methods(p); - ret mk_item(p, lo, p.last_span.hi, ident, - ast::item_iface(tps, meths), attrs); -} - -// Parses three variants (with the initial params always optional): -// impl <T: copy> of to_str for [T] { ... } -// impl name<T> of to_str for [T] { ... } -// impl name<T> for [T] { ... } -fn parse_item_impl(p: parser, attrs: [ast::attribute]) -> @ast::item { - let lo = p.last_span.lo; - fn wrap_path(p: parser, pt: @ast::path) -> @ast::ty { - @{node: ast::ty_path(pt, p.get_id()), span: pt.span} - } - let (ident, tps) = if !is_word(p, "of") { - if p.token == token::LT { (none, parse_ty_params(p)) } - else { (some(parse_ident(p)), parse_ty_params(p)) } - } else { (none, []) }; - let ifce = if eat_word(p, "of") { - let path = parse_path_and_ty_param_substs(p, false); - if option::is_none(ident) { - ident = some(path.node.idents[vec::len(path.node.idents) - 1u]); - } - some(wrap_path(p, path)) - } else { none }; - let ident = alt ident { - some(name) { name } - none { expect_word(p, "of"); fail; } - }; - expect_word(p, "for"); - let ty = parse_ty(p, false), meths = []; - expect(p, token::LBRACE); - while !eat(p, token::RBRACE) { meths += [parse_method(p)]; } - ret mk_item(p, lo, p.last_span.hi, ident, - ast::item_impl(tps, ifce, ty, meths), attrs); -} - -fn parse_item_res(p: parser, attrs: [ast::attribute]) -> @ast::item { - let lo = p.last_span.lo; - let ident = parse_value_ident(p); - let ty_params = parse_ty_params(p); - expect(p, token::LPAREN); - let arg_ident = parse_value_ident(p); - expect(p, token::COLON); - let t = parse_ty(p, false); - expect(p, token::RPAREN); - let dtor = parse_block_no_value(p); - let decl = - {inputs: - [{mode: ast::expl(ast::by_ref), ty: t, - ident: arg_ident, id: p.get_id()}], - output: @spanned(lo, lo, ast::ty_nil), - purity: ast::impure_fn, - cf: ast::return_val, - constraints: []}; - ret mk_item(p, lo, dtor.span.hi, ident, - ast::item_res(decl, ty_params, dtor, p.get_id(), p.get_id()), - attrs); -} - -fn parse_item_class(p: parser, attrs: [ast::attribute]) -> @ast::item { - let lo = p.last_span.lo; - let class_name = parse_value_ident(p); - let class_path = ident_to_path(p.last_span, class_name); - let ty_params = parse_ty_params(p); - expect(p, token::LBRACE); - let items: [@ast::class_item] = []; - let ctor_id = p.get_id(); - let the_ctor : option<(ast::fn_decl, ast::blk)> = none; - while p.token != token::RBRACE { - alt parse_class_item(p, class_path) { - ctor_decl(a_fn_decl, blk) { - the_ctor = some((a_fn_decl, blk)); - } - plain_decl(a_decl) { - items += [@{node: {privacy: ast::pub, decl: a_decl}, - span: p.last_span}]; - } - priv_decls(some_decls) { - items += vec::map(some_decls, {|d| - @{node: {privacy: ast::priv, decl: d}, - span: p.last_span}}); - } - } - } - p.bump(); - alt the_ctor { - some((ct_d, ct_b)) { ret mk_item(p, lo, p.last_span.hi, class_name, - ast::item_class(ty_params, items, ctor_id, ct_d, ct_b), attrs); } - /* - Is it strange for the parser to check this? - */ - none { /* parse error */ fail "Class with no ctor"; } - } -} - -// lets us identify the constructor declaration at -// parse time -// we don't really want just the fn_decl... -enum class_contents { ctor_decl(ast::fn_decl, ast::blk), - // assumed to be public - plain_decl(ast::class_member), - // contents of a priv section -- - // parse_class_item ensures that - // none of these are a ctor decl - priv_decls([ast::class_member])} - - fn parse_class_item(p:parser, class_name:@ast::path) -> class_contents { - if eat_word(p, "new") { - // Can ctors have attrs? - // result type is always the type of the class - let decl_ = parse_fn_decl(p, ast::impure_fn); - let decl = {output: @{node: ast::ty_path(class_name, p.get_id()), - span: decl_.output.span} - with decl_}; - let body = parse_block(p); - ret ctor_decl(decl, body); - } - // FIXME: refactor - else if eat_word(p, "priv") { - expect(p, token::LBRACE); - let results = []; - while p.token != token::RBRACE { - alt parse_item(p, []) { - some(i) { - results += [ast::class_method(i)]; - } - _ { - let a_var = parse_instance_var(p); - expect(p, token::SEMI); - results += [a_var]; - } - } - } - p.bump(); - ret priv_decls(results); - } - else { - // Probably need to parse attrs - alt parse_item(p, []) { - some(i) { - ret plain_decl(ast::class_method(i)); - } - _ { - let a_var = parse_instance_var(p); - expect(p, token::SEMI); - ret plain_decl(a_var); - } - } - } -} - -fn parse_mod_items(p: parser, term: token::token, - first_item_attrs: [ast::attribute]) -> ast::_mod { - // Shouldn't be any view items since we've already parsed an item attr - let view_items = maybe_parse_view(p, first_item_attrs); - let items: [@ast::item] = []; - let initial_attrs = first_item_attrs; - while p.token != term { - let attrs = initial_attrs + parse_outer_attributes(p); - #debug["parse_mod_items: parse_item(attrs=%?)", attrs]; - alt parse_item(p, attrs) { - some(i) { items += [i]; } - _ { - p.fatal("expected item but found '" + - token::to_str(p.reader, p.token) + "'"); - } - } - #debug["parse_mod_items: attrs=%?", attrs]; - initial_attrs = []; - } - - if vec::is_not_empty(initial_attrs) { - // We parsed attributes for the first item but didn't find the item - p.fatal("expected item"); - } - - ret {view_items: view_items, items: items}; -} - -fn parse_item_const(p: parser, attrs: [ast::attribute]) -> @ast::item { - let lo = p.last_span.lo; - let id = parse_value_ident(p); - expect(p, token::COLON); - let ty = parse_ty(p, false); - expect(p, token::EQ); - let e = parse_expr(p); - let hi = p.span.hi; - expect(p, token::SEMI); - ret mk_item(p, lo, hi, id, ast::item_const(ty, e), attrs); -} - -fn parse_item_mod(p: parser, attrs: [ast::attribute]) -> @ast::item { - let lo = p.last_span.lo; - let id = parse_ident(p); - expect(p, token::LBRACE); - let inner_attrs = parse_inner_attrs_and_next(p); - let first_item_outer_attrs = inner_attrs.next; - let m = parse_mod_items(p, token::RBRACE, first_item_outer_attrs); - let hi = p.span.hi; - expect(p, token::RBRACE); - ret mk_item(p, lo, hi, id, ast::item_mod(m), attrs + inner_attrs.inner); -} - -fn parse_item_native_fn(p: parser, attrs: [ast::attribute], - purity: ast::purity) -> @ast::native_item { - let lo = p.last_span.lo; - let t = parse_fn_header(p); - let decl = parse_fn_decl(p, purity); - let hi = p.span.hi; - expect(p, token::SEMI); - ret @{ident: t.ident, - attrs: attrs, - node: ast::native_item_fn(decl, t.tps), - id: p.get_id(), - span: ast_util::mk_sp(lo, hi)}; -} - -fn parse_fn_purity(p: parser) -> ast::purity { - if eat_word(p, "fn") { ast::impure_fn } - else if eat_word(p, "pure") { expect_word(p, "fn"); ast::pure_fn } - else if eat_word(p, "unsafe") { expect_word(p, "fn"); ast::unsafe_fn } - else { unexpected(p, p.token); } -} - -fn parse_native_item(p: parser, attrs: [ast::attribute]) -> - @ast::native_item { - parse_item_native_fn(p, attrs, parse_fn_purity(p)) -} - -fn parse_native_mod_items(p: parser, first_item_attrs: [ast::attribute]) -> - ast::native_mod { - // Shouldn't be any view items since we've already parsed an item attr - let view_items = - if vec::len(first_item_attrs) == 0u { - parse_native_view(p) - } else { [] }; - let items: [@ast::native_item] = []; - let initial_attrs = first_item_attrs; - while p.token != token::RBRACE { - let attrs = initial_attrs + parse_outer_attributes(p); - initial_attrs = []; - items += [parse_native_item(p, attrs)]; - } - ret {view_items: view_items, - items: items}; -} - -fn parse_item_native_mod(p: parser, attrs: [ast::attribute]) -> @ast::item { - let lo = p.last_span.lo; - expect_word(p, "mod"); - let id = parse_ident(p); - expect(p, token::LBRACE); - let more_attrs = parse_inner_attrs_and_next(p); - let inner_attrs = more_attrs.inner; - let first_item_outer_attrs = more_attrs.next; - let m = parse_native_mod_items(p, first_item_outer_attrs); - let hi = p.span.hi; - expect(p, token::RBRACE); - ret mk_item(p, lo, hi, id, ast::item_native_mod(m), attrs + inner_attrs); -} - -fn parse_type_decl(p: parser) -> {lo: uint, ident: ast::ident} { - let lo = p.last_span.lo; - let id = parse_ident(p); - ret {lo: lo, ident: id}; -} - -fn parse_item_type(p: parser, attrs: [ast::attribute]) -> @ast::item { - let t = parse_type_decl(p); - let tps = parse_ty_params(p); - expect(p, token::EQ); - let ty = parse_ty(p, false); - let hi = p.span.hi; - expect(p, token::SEMI); - ret mk_item(p, t.lo, hi, t.ident, ast::item_ty(ty, tps), attrs); -} - -fn parse_item_enum(p: parser, attrs: [ast::attribute]) -> @ast::item { - let lo = p.last_span.lo; - let id = parse_ident(p); - let ty_params = parse_ty_params(p); - let variants: [ast::variant] = []; - // Newtype syntax - if p.token == token::EQ { - if p.bad_expr_words.contains_key(id) { - p.fatal("found " + id + " in enum constructor position"); - } - p.bump(); - let ty = parse_ty(p, false); - expect(p, token::SEMI); - let variant = - spanned(ty.span.lo, ty.span.hi, - {name: id, - attrs: [], - args: [{ty: ty, id: p.get_id()}], - id: p.get_id(), - disr_expr: none}); - ret mk_item(p, lo, ty.span.hi, id, - ast::item_enum([variant], ty_params), attrs); - } - expect(p, token::LBRACE); - - let all_nullary = true, have_disr = false; - - while p.token != token::RBRACE { - let variant_attrs = parse_outer_attributes(p); - let vlo = p.span.lo; - let ident = parse_value_ident(p); - let args = [], disr_expr = none; - if p.token == token::LPAREN { - all_nullary = false; - let arg_tys = parse_seq(token::LPAREN, token::RPAREN, - seq_sep(token::COMMA), - {|p| parse_ty(p, false)}, p); - for ty in arg_tys.node { - args += [{ty: ty, id: p.get_id()}]; - } - } else if eat(p, token::EQ) { - have_disr = true; - disr_expr = some(parse_expr(p)); - } - - let vr = {name: ident, attrs: variant_attrs, - args: args, id: p.get_id(), - disr_expr: disr_expr}; - variants += [spanned(vlo, p.last_span.hi, vr)]; - - if !eat(p, token::COMMA) { break; } - } - expect(p, token::RBRACE); - if (have_disr && !all_nullary) { - p.fatal("discriminator values can only be used with a c-like enum"); - } - ret mk_item(p, lo, p.last_span.hi, id, - ast::item_enum(variants, ty_params), attrs); -} - -fn parse_fn_ty_proto(p: parser) -> ast::proto { - alt p.token { - token::AT { - p.bump(); - ast::proto_box - } - token::TILDE { - p.bump(); - ast::proto_uniq - } - token::BINOP(token::AND) { - p.bump(); - ast::proto_block - } - _ { - ast::proto_any - } - } -} - -fn fn_expr_lookahead(tok: token::token) -> bool { - alt tok { - token::LPAREN | token::AT | token::TILDE | token::BINOP(_) { - true - } - _ { - false - } - } -} - -fn parse_item(p: parser, attrs: [ast::attribute]) -> option<@ast::item> { - if eat_word(p, "const") { - ret some(parse_item_const(p, attrs)); - } else if is_word(p, "fn") && !fn_expr_lookahead(p.look_ahead(1u)) { - p.bump(); - ret some(parse_item_fn(p, ast::impure_fn, attrs)); - } else if eat_word(p, "pure") { - expect_word(p, "fn"); - ret some(parse_item_fn(p, ast::pure_fn, attrs)); - } else if is_word(p, "unsafe") && p.look_ahead(1u) != token::LBRACE { - p.bump(); - expect_word(p, "fn"); - ret some(parse_item_fn(p, ast::unsafe_fn, attrs)); - } else if eat_word(p, "crust") { - expect_word(p, "fn"); - ret some(parse_item_fn(p, ast::crust_fn, attrs)); - } else if eat_word(p, "mod") { - ret some(parse_item_mod(p, attrs)); - } else if eat_word(p, "native") { - ret some(parse_item_native_mod(p, attrs)); - } if eat_word(p, "type") { - ret some(parse_item_type(p, attrs)); - } else if eat_word(p, "enum") { - ret some(parse_item_enum(p, attrs)); - } else if eat_word(p, "iface") { - ret some(parse_item_iface(p, attrs)); - } else if eat_word(p, "impl") { - ret some(parse_item_impl(p, attrs)); - } else if eat_word(p, "resource") { - ret some(parse_item_res(p, attrs)); - } else if eat_word(p, "class") { - ret some(parse_item_class(p, attrs)); - } -else { ret none; } -} - -// A type to distingush between the parsing of item attributes or syntax -// extensions, which both begin with token.POUND -type attr_or_ext = option<either::t<[ast::attribute], @ast::expr>>; - -fn parse_outer_attrs_or_ext( - p: parser, - first_item_attrs: [ast::attribute]) -> attr_or_ext { - let expect_item_next = vec::is_not_empty(first_item_attrs); - if p.token == token::POUND { - let lo = p.span.lo; - if p.look_ahead(1u) == token::LBRACKET { - p.bump(); - let first_attr = parse_attribute_naked(p, ast::attr_outer, lo); - ret some(left([first_attr] + parse_outer_attributes(p))); - } else if !(p.look_ahead(1u) == token::LT - || p.look_ahead(1u) == token::LBRACKET - || expect_item_next) { - p.bump(); - ret some(right(parse_syntax_ext_naked(p, lo))); - } else { ret none; } - } else { ret none; } -} - -// Parse attributes that appear before an item -fn parse_outer_attributes(p: parser) -> [ast::attribute] { - let attrs: [ast::attribute] = []; - while p.token == token::POUND { - attrs += [parse_attribute(p, ast::attr_outer)]; - } - ret attrs; -} - -fn parse_attribute(p: parser, style: ast::attr_style) -> ast::attribute { - let lo = p.span.lo; - expect(p, token::POUND); - ret parse_attribute_naked(p, style, lo); -} - -fn parse_attribute_naked(p: parser, style: ast::attr_style, lo: uint) -> - ast::attribute { - expect(p, token::LBRACKET); - let meta_item = parse_meta_item(p); - expect(p, token::RBRACKET); - let hi = p.span.hi; - ret spanned(lo, hi, {style: style, value: *meta_item}); -} - -// Parse attributes that appear after the opening of an item, each terminated -// by a semicolon. In addition to a vector of inner attributes, this function -// also returns a vector that may contain the first outer attribute of the -// next item (since we can't know whether the attribute is an inner attribute -// of the containing item or an outer attribute of the first contained item -// until we see the semi). -fn parse_inner_attrs_and_next(p: parser) -> - {inner: [ast::attribute], next: [ast::attribute]} { - let inner_attrs: [ast::attribute] = []; - let next_outer_attrs: [ast::attribute] = []; - while p.token == token::POUND { - if p.look_ahead(1u) != token::LBRACKET { - // This is an extension - break; - } - let attr = parse_attribute(p, ast::attr_inner); - if p.token == token::SEMI { - p.bump(); - inner_attrs += [attr]; - } else { - // It's not really an inner attribute - let outer_attr = - spanned(attr.span.lo, attr.span.hi, - {style: ast::attr_outer, value: attr.node.value}); - next_outer_attrs += [outer_attr]; - break; - } - } - ret {inner: inner_attrs, next: next_outer_attrs}; -} - -fn parse_meta_item(p: parser) -> @ast::meta_item { - let lo = p.span.lo; - let ident = parse_ident(p); - alt p.token { - token::EQ { - p.bump(); - let lit = parse_lit(p); - let hi = p.span.hi; - ret @spanned(lo, hi, ast::meta_name_value(ident, lit)); - } - token::LPAREN { - let inner_items = parse_meta_seq(p); - let hi = p.span.hi; - ret @spanned(lo, hi, ast::meta_list(ident, inner_items)); - } - _ { - let hi = p.span.hi; - ret @spanned(lo, hi, ast::meta_word(ident)); - } - } -} - -fn parse_meta_seq(p: parser) -> [@ast::meta_item] { - ret parse_seq(token::LPAREN, token::RPAREN, seq_sep(token::COMMA), - parse_meta_item, p).node; -} - -fn parse_optional_meta(p: parser) -> [@ast::meta_item] { - alt p.token { token::LPAREN { ret parse_meta_seq(p); } _ { ret []; } } -} - -fn parse_use(p: parser) -> ast::view_item_ { - let ident = parse_ident(p); - let metadata = parse_optional_meta(p); - ret ast::view_item_use(ident, metadata, p.get_id()); -} - -fn parse_view_path(p: parser) -> @ast::view_path { - let lo = p.span.lo; - let first_ident = parse_ident(p); - let path = [first_ident]; - #debug("parsed view_path: %s", first_ident); - alt p.token { - token::EQ { - // x = foo::bar - p.bump(); - path = [parse_ident(p)]; - while p.token == token::MOD_SEP { - p.bump(); - let id = parse_ident(p); - path += [id]; - } - let hi = p.span.hi; - ret @spanned(lo, hi, - ast::view_path_simple(first_ident, - @path, p.get_id())); - } - - token::MOD_SEP { - // foo::bar or foo::{a,b,c} or foo::* - while p.token == token::MOD_SEP { - p.bump(); - - alt p.token { - - token::IDENT(i, _) { - p.bump(); - path += [p.get_str(i)]; - } - - // foo::bar::{a,b,c} - token::LBRACE { - let idents = - parse_seq(token::LBRACE, token::RBRACE, - seq_sep(token::COMMA), - parse_path_list_ident, p).node; - let hi = p.span.hi; - ret @spanned(lo, hi, - ast::view_path_list(@path, idents, - p.get_id())); - } - - // foo::bar::* - token::BINOP(token::STAR) { - p.bump(); - let hi = p.span.hi; - ret @spanned(lo, hi, - ast::view_path_glob(@path, - p.get_id())); - } - - _ { break; } - } - } - } - _ { } - } - let hi = p.span.hi; - let last = path[vec::len(path) - 1u]; - ret @spanned(lo, hi, - ast::view_path_simple(last, @path, - p.get_id())); -} - -fn parse_view_paths(p: parser) -> [@ast::view_path] { - let vp = [parse_view_path(p)]; - while p.token == token::COMMA { - p.bump(); - vp += [parse_view_path(p)]; - } - ret vp; -} - -fn parse_view_item(p: parser) -> @ast::view_item { - let lo = p.span.lo; - let the_item = - if eat_word(p, "use") { - parse_use(p) - } else if eat_word(p, "import") { - ast::view_item_import(parse_view_paths(p)) - } else if eat_word(p, "export") { - ast::view_item_export(parse_view_paths(p)) - } else { - fail - }; - let hi = p.span.lo; - expect(p, token::SEMI); - ret @spanned(lo, hi, the_item); -} - -fn is_view_item(p: parser) -> bool { - alt p.token { - token::IDENT(sid, false) { - let st = p.get_str(sid); - ret str::eq(st, "use") || str::eq(st, "import") || - str::eq(st, "export"); - } - _ { ret false; } - } -} - -fn maybe_parse_view( - p: parser, - first_item_attrs: [ast::attribute]) -> [@ast::view_item] { - - maybe_parse_view_while(p, first_item_attrs, is_view_item) -} - -fn maybe_parse_view_import_only( - p: parser, - first_item_attrs: [ast::attribute]) -> [@ast::view_item] { - - maybe_parse_view_while(p, first_item_attrs, bind is_word(_, "import")) -} - -fn maybe_parse_view_while( - p: parser, - first_item_attrs: [ast::attribute], - f: fn@(parser) -> bool) -> [@ast::view_item] { - - if vec::len(first_item_attrs) == 0u { - let items = []; - while f(p) { items += [parse_view_item(p)]; } - ret items; - } else { - // Shouldn't be any view items since we've already parsed an item attr - ret []; - } -} - -fn parse_native_view(p: parser) -> [@ast::view_item] { - maybe_parse_view_while(p, [], is_view_item) -} - -fn parse_crate_from_source_file(input: str, cfg: ast::crate_cfg, - sess: parse_sess) -> @ast::crate { - let p = new_parser_from_file(sess, cfg, input, SOURCE_FILE); - let r = parse_crate_mod(p, cfg); - sess.chpos = p.reader.chpos; - sess.byte_pos = sess.byte_pos + p.reader.pos; - ret r; -} - - -fn parse_expr_from_source_str(name: str, source: @str, cfg: ast::crate_cfg, - sess: parse_sess) -> @ast::expr { - let p = new_parser_from_source_str(sess, cfg, name, fss_none, source); - let r = parse_expr(p); - sess.chpos = p.reader.chpos; - sess.byte_pos = sess.byte_pos + p.reader.pos; - ret r; -} - -fn parse_from_source_str<T>(f: fn (p: parser) -> T, - name: str, ss: codemap::file_substr, - source: @str, cfg: ast::crate_cfg, - sess: parse_sess) - -> T -{ - let p = new_parser_from_source_str(sess, cfg, name, ss, source); - let r = f(p); - if !p.reader.is_eof() { - p.reader.fatal("expected end-of-string"); - } - sess.chpos = p.reader.chpos; - sess.byte_pos = sess.byte_pos + p.reader.pos; - ret r; -} - -fn parse_crate_from_source_str(name: str, source: @str, cfg: ast::crate_cfg, - sess: parse_sess) -> @ast::crate { - let p = new_parser_from_source_str(sess, cfg, name, fss_none, source); - let r = parse_crate_mod(p, cfg); - sess.chpos = p.reader.chpos; - sess.byte_pos = sess.byte_pos + p.reader.pos; - ret r; -} - -// Parses a source module as a crate -fn parse_crate_mod(p: parser, _cfg: ast::crate_cfg) -> @ast::crate { - let lo = p.span.lo; - let crate_attrs = parse_inner_attrs_and_next(p); - let first_item_outer_attrs = crate_attrs.next; - let m = parse_mod_items(p, token::EOF, first_item_outer_attrs); - ret @spanned(lo, p.span.lo, - {directives: [], - module: m, - attrs: crate_attrs.inner, - config: p.cfg}); -} - -fn parse_str(p: parser) -> str { - alt p.token { - token::LIT_STR(s) { p.bump(); p.get_str(s) } - _ { - p.fatal("expected string literal") - } - } -} - -// Logic for parsing crate files (.rc) -// -// Each crate file is a sequence of directives. -// -// Each directive imperatively extends its environment with 0 or more items. -fn parse_crate_directive(p: parser, first_outer_attr: [ast::attribute]) -> - ast::crate_directive { - - // Collect the next attributes - let outer_attrs = first_outer_attr + parse_outer_attributes(p); - // In a crate file outer attributes are only going to apply to mods - let expect_mod = vec::len(outer_attrs) > 0u; - - let lo = p.span.lo; - if expect_mod || is_word(p, "mod") { - expect_word(p, "mod"); - let id = parse_ident(p); - alt p.token { - // mod x = "foo.rs"; - token::SEMI { - let hi = p.span.hi; - p.bump(); - ret spanned(lo, hi, ast::cdir_src_mod(id, outer_attrs)); - } - // mod x = "foo_dir" { ...directives... } - token::LBRACE { - p.bump(); - let inner_attrs = parse_inner_attrs_and_next(p); - let mod_attrs = outer_attrs + inner_attrs.inner; - let next_outer_attr = inner_attrs.next; - let cdirs = - parse_crate_directives(p, token::RBRACE, next_outer_attr); - let hi = p.span.hi; - expect(p, token::RBRACE); - ret spanned(lo, hi, - ast::cdir_dir_mod(id, cdirs, mod_attrs)); - } - t { unexpected(p, t); } - } - } else if is_view_item(p) { - let vi = parse_view_item(p); - ret spanned(lo, vi.span.hi, ast::cdir_view_item(vi)); - } else { ret p.fatal("expected crate directive"); } -} - -fn parse_crate_directives(p: parser, term: token::token, - first_outer_attr: [ast::attribute]) -> - [@ast::crate_directive] { - - // This is pretty ugly. If we have an outer attribute then we can't accept - // seeing the terminator next, so if we do see it then fail the same way - // parse_crate_directive would - if vec::len(first_outer_attr) > 0u && p.token == term { - expect_word(p, "mod"); - } - - let cdirs: [@ast::crate_directive] = []; - let first_outer_attr = first_outer_attr; - while p.token != term { - let cdir = @parse_crate_directive(p, first_outer_attr); - cdirs += [cdir]; - first_outer_attr = []; - } - ret cdirs; -} - -fn parse_crate_from_crate_file(input: str, cfg: ast::crate_cfg, - sess: parse_sess) -> @ast::crate { - let p = new_parser_from_file(sess, cfg, input, CRATE_FILE); - let lo = p.span.lo; - let prefix = std::fs::dirname(p.reader.filemap.name); - let leading_attrs = parse_inner_attrs_and_next(p); - let crate_attrs = leading_attrs.inner; - let first_cdir_attr = leading_attrs.next; - let cdirs = parse_crate_directives(p, token::EOF, first_cdir_attr); - sess.chpos = p.reader.chpos; - sess.byte_pos = sess.byte_pos + p.reader.pos; - let cx = - @{p: p, - sess: sess, - cfg: p.cfg}; - let (companionmod, _) = fs::splitext(fs::basename(input)); - let (m, attrs) = eval::eval_crate_directives_to_mod( - cx, cdirs, prefix, option::some(companionmod)); - let hi = p.span.hi; - expect(p, token::EOF); - ret @spanned(lo, hi, - {directives: cdirs, - module: m, - attrs: crate_attrs + attrs, - config: p.cfg}); -} - -fn parse_crate_from_file(input: str, cfg: ast::crate_cfg, sess: parse_sess) -> - @ast::crate { - if str::ends_with(input, ".rc") { - parse_crate_from_crate_file(input, cfg, sess) - } else if str::ends_with(input, ".rs") { - parse_crate_from_source_file(input, cfg, sess) - } else { - sess.span_diagnostic.handler().fatal("unknown input file type: " + - input) - } -} - -// -// Local Variables: -// mode: rust -// fill-column: 78; -// indent-tabs-mode: nil -// c-basic-offset: 4 -// buffer-file-coding-system: utf-8-unix -// End: -// |
