rust/src/comp/syntax/parse/parser.rs
2011-09-28 12:58:33 -07:00

2589 lines
83 KiB
Rust

import std::{io, vec, str, option, either};
import std::option::{some, none};
import std::either::{left, right};
import std::map::{hashmap, new_str_hash};
import token::can_begin_expr;
import ex = ext::base;
import codemap::span;
import util::interner;
import ast::{node_id, spanned};
tag restriction { UNRESTRICTED; RESTRICT_NO_CALL_EXPRS; }
tag file_type { CRATE_FILE; SOURCE_FILE; }
type parse_sess = @{cm: codemap::codemap, mutable next_id: node_id};
fn next_node_id(sess: parse_sess) -> node_id {
let rv = sess.next_id;
sess.next_id += 1;
ret rv;
}
type parser =
obj {
fn peek() -> token::token;
fn bump();
fn swap(token::token, uint, uint);
fn look_ahead(uint) -> token::token;
fn fatal(str) -> ! ;
fn span_fatal(span, str) -> ! ;
fn warn(str);
fn restrict(restriction);
fn get_restriction() -> restriction;
fn get_file_type() -> file_type;
fn get_cfg() -> ast::crate_cfg;
fn get_span() -> span;
fn get_lo_pos() -> uint;
fn get_hi_pos() -> uint;
fn get_last_lo_pos() -> uint;
fn get_last_hi_pos() -> uint;
fn get_prec_table() -> @[op_spec];
fn get_str(token::str_num) -> str;
fn get_reader() -> lexer::reader;
fn get_filemap() -> codemap::filemap;
fn get_bad_expr_words() -> hashmap<str, ()>;
fn get_chpos() -> uint;
fn get_byte_pos() -> uint;
fn get_id() -> node_id;
fn get_sess() -> parse_sess;
};
fn new_parser_from_file(sess: parse_sess, cfg: ast::crate_cfg, path: str,
chpos: uint, byte_pos: uint, ftype: file_type) ->
parser {
let src = io::read_whole_file_str(path);
let filemap = codemap::new_filemap(path, chpos, byte_pos);
sess.cm.files += [filemap];
let itr = @interner::mk(str::hash, str::eq);
let rdr = lexer::new_reader(sess.cm, src, filemap, itr);
ret new_parser(sess, cfg, rdr, ftype);
}
fn new_parser(sess: parse_sess, cfg: ast::crate_cfg, rdr: lexer::reader,
ftype: file_type) -> parser {
obj stdio_parser(sess: parse_sess,
cfg: ast::crate_cfg,
ftype: file_type,
mutable tok: token::token,
mutable tok_span: span,
mutable last_tok_span: span,
mutable buffer: [{tok: token::token, span: span}],
mutable restr: restriction,
rdr: lexer::reader,
precs: @[op_spec],
bad_words: hashmap<str, ()>) {
fn peek() -> token::token { ret tok; }
fn bump() {
last_tok_span = tok_span;
if vec::len(buffer) == 0u {
let next = lexer::next_token(rdr);
tok = next.tok;
tok_span = ast_util::mk_sp(next.chpos, rdr.get_chpos());
} else {
let next = vec::pop(buffer);
tok = next.tok;
tok_span = next.span;
}
}
fn swap(next: token::token, lo: uint, hi: uint) {
tok = next;
tok_span = ast_util::mk_sp(lo, hi);
}
fn look_ahead(distance: uint) -> token::token {
while vec::len(buffer) < distance {
let next = lexer::next_token(rdr);
let sp = ast_util::mk_sp(next.chpos, rdr.get_chpos());
buffer = [{tok: next.tok, span: sp}] + buffer;
}
ret buffer[distance - 1u].tok;
}
fn fatal(m: str) -> ! {
self.span_fatal(self.get_span(), m);
}
fn span_fatal(sp: span, m: str) -> ! {
codemap::emit_error(some(sp), m, sess.cm);
fail;
}
fn warn(m: str) {
codemap::emit_warning(some(self.get_span()), m, sess.cm);
}
fn restrict(r: restriction) { restr = r; }
fn get_restriction() -> restriction { ret restr; }
fn get_span() -> span { ret tok_span; }
fn get_lo_pos() -> uint { ret tok_span.lo; }
fn get_hi_pos() -> uint { ret tok_span.hi; }
fn get_last_lo_pos() -> uint { ret last_tok_span.lo; }
fn get_last_hi_pos() -> uint { ret last_tok_span.hi; }
fn get_file_type() -> file_type { ret ftype; }
fn get_cfg() -> ast::crate_cfg { ret cfg; }
fn get_prec_table() -> @[op_spec] { ret precs; }
fn get_str(i: token::str_num) -> str {
ret interner::get(*rdr.get_interner(), i);
}
fn get_reader() -> lexer::reader { ret rdr; }
fn get_filemap() -> codemap::filemap { ret rdr.get_filemap(); }
fn get_bad_expr_words() -> hashmap<str, ()> { ret bad_words; }
fn get_chpos() -> uint { ret rdr.get_chpos(); }
fn get_byte_pos() -> uint { ret rdr.get_byte_pos(); }
fn get_id() -> node_id { ret next_node_id(sess); }
fn get_sess() -> parse_sess { ret sess; }
}
let tok0 = lexer::next_token(rdr);
let span0 = ast_util::mk_sp(tok0.chpos, rdr.get_chpos());
ret stdio_parser(sess, cfg, ftype, tok0.tok, span0, span0, [],
UNRESTRICTED, rdr, prec_table(), 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();
words.insert("mod", ());
words.insert("if", ());
words.insert("else", ());
words.insert("while", ());
words.insert("do", ());
words.insert("alt", ());
words.insert("for", ());
words.insert("each", ());
words.insert("break", ());
words.insert("cont", ());
words.insert("put", ());
words.insert("ret", ());
words.insert("be", ());
words.insert("fail", ());
words.insert("type", ());
words.insert("resource", ());
words.insert("check", ());
words.insert("assert", ());
words.insert("claim", ());
words.insert("prove", ());
words.insert("native", ());
words.insert("fn", ());
words.insert("lambda", ());
words.insert("pure", ());
words.insert("iter", ());
words.insert("block", ());
words.insert("import", ());
words.insert("export", ());
words.insert("let", ());
words.insert("const", ());
words.insert("log", ());
words.insert("log_err", ());
words.insert("tag", ());
words.insert("obj", ());
words.insert("copy", ());
ret words;
}
fn unexpected(p: parser, t: token::token) -> ! {
let s: str = "unexpected token: ";
s += token::to_str(p.get_reader(), t);
p.fatal(s);
}
fn expect(p: parser, t: token::token) {
if p.peek() == t {
p.bump();
} else {
let s: str = "expecting ";
s += token::to_str(p.get_reader(), t);
s += ", found ";
s += token::to_str(p.get_reader(), p.peek());
p.fatal(s);
}
}
fn expect_gt(p: parser) {
if p.peek() == token::GT {
p.bump();
} else if p.peek() == token::BINOP(token::LSR) {
p.swap(token::GT, p.get_lo_pos() + 1u, p.get_hi_pos());
} else if p.peek() == token::BINOP(token::ASR) {
p.swap(token::BINOP(token::LSR), p.get_lo_pos() + 1u, p.get_hi_pos());
} else {
let s: str = "expecting ";
s += token::to_str(p.get_reader(), token::GT);
s += ", found ";
s += token::to_str(p.get_reader(), p.peek());
p.fatal(s);
}
}
fn spanned<@T>(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.peek() {
token::IDENT(i, _) { p.bump(); ret p.get_str(i); }
_ { p.fatal("expecting ident"); }
}
}
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.peek() == tok { p.bump(); true } else { false };
}
fn is_word(p: parser, word: str) -> bool {
ret alt p.peek() {
token::IDENT(sid, false) { str::eq(word, p.get_str(sid)) }
_ { false }
};
}
fn eat_word(p: parser, word: str) -> bool {
alt p.peek() {
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.get_reader(), p.peek()));
}
}
fn check_bad_word(p: parser) {
alt p.peek() {
token::IDENT(sid, false) {
let w = p.get_str(sid);
if p.get_bad_expr_words().contains_key(w) {
p.fatal("found " + w + " in expression position");
}
}
_ { }
}
}
fn parse_ty_fn(proto: ast::proto, p: parser) -> ast::ty_ {
fn parse_fn_input_ty(p: parser) -> ast::ty_arg {
let lo = p.get_lo_pos();
let mode = parse_arg_mode(p);
// Ignore arg name, if present
if is_plain_ident(p) && p.look_ahead(1u) == token::COLON {
p.bump();
p.bump();
}
let t = parse_ty(p, false);
ret spanned(lo, t.span.hi, {mode: mode, ty: t});
}
let inputs =
parse_seq(token::LPAREN, token::RPAREN, some(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, vec::len(inputs.node));
ret ast::ty_fn(proto, inputs.node, ret_ty, ret_style, constrs);
}
fn parse_proto(p: parser) -> ast::proto {
if eat_word(p, "iter") {
ret ast::proto_iter;
} else if eat_word(p, "fn") {
ret ast::proto_fn;
} else if eat_word(p, "block") {
ret ast::proto_block;
} else { unexpected(p, p.peek()); }
}
fn parse_ty_obj(p: parser, &hi: uint) -> ast::ty_ {
fn parse_method_sig(p: parser) -> ast::ty_method {
let flo = p.get_lo_pos();
let proto: ast::proto = parse_proto(p);
let ident = parse_value_ident(p);
let f = parse_ty_fn(proto, p);
expect(p, token::SEMI);
alt f {
ast::ty_fn(proto, inputs, output, cf, constrs) {
ret spanned(flo, output.span.hi,
{proto: proto,
ident: ident,
inputs: inputs,
output: output,
cf: cf,
constrs: constrs});
}
}
}
let meths =
parse_seq(token::LBRACE, token::RBRACE, none, parse_method_sig, p);
hi = meths.span.hi;
ret ast::ty_obj(meths.node);
}
fn parse_mt(p: parser) -> ast::mt {
let mut = parse_mutability(p);
let t = parse_ty(p, false);
ret {ty: t, mut: mut};
}
fn parse_ty_field(p: parser) -> ast::ty_field {
let lo = p.get_lo_pos();
let mut = 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, mut: mut}});
}
// 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.get_span();
let carg = ast::carg_base;
expect(p, token::BINOP(token::STAR));
if p.peek() == token::DOT {
// "*..." notation for record fields
p.bump();
let pth: ast::path = 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.get_span();
let carg = ast::carg_base;
if p.peek() == 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.get_lo_pos();
let path = parse_path(p);
let pf = bind parse_constr_arg(fn_args, _);
let args: {node: [@ast::constr_arg], span: span} =
parse_seq(token::LPAREN, token::RPAREN, some(token::COMMA), pf, 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.get_lo_pos();
let path = parse_path(p);
let args: [@ast::ty_constr_arg] =
parse_seq(token::LPAREN, token::RPAREN, some(token::COMMA),
parse_type_constr_arg, p).node;
let hi = p.get_lo_pos();
let tc: ast::ty_constr_ = {path: path, args: args, id: p.get_id()};
ret @spanned(lo, hi, tc);
}
fn parse_constrs<T>(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.peek() == 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)
-> @ast::ty {
let lo = p.get_lo_pos();
if colons_before_params && p.peek() == token::MOD_SEP {
p.bump();
expect(p, token::LT);
} else if !colons_before_params && p.peek() == token::LT {
p.bump();
} else { ret @spanned(lo, p.get_lo_pos(), orig_t); }
// If we're here, we have explicit type parameter instantiation.
let seq = parse_seq_to_gt(some(token::COMMA), bind parse_ty(_, false), p);
alt orig_t {
ast::ty_path(pth, ann) {
let hi = p.get_hi_pos();
ret @spanned(lo, hi,
ast::ty_path(spanned(lo, 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, n_args: uint) -> (ast::ret_style, @ast::ty) {
ret if eat(p, token::RARROW) {
let lo = p.get_lo_pos();
if eat(p, token::NOT) {
(ast::noreturn, @spanned(lo, p.get_last_hi_pos(), ast::ty_bot))
} else {
let style = ast::return_val;
if eat(p, token::BINOP(token::AND)) {
if n_args == 0u {
p.fatal("can not return reference from argument-less fn");
}
let mut_root = eat(p, token::NOT), arg = 1u;
alt p.peek() {
token::LIT_INT(val) { p.bump(); arg = val as uint; }
_ { if n_args > 1u {
p.fatal("must specify referenced parameter");
} }
}
if arg > n_args {
p.fatal("referenced argument does not exist");
}
if arg == 0u {
p.fatal("referenced argument can't be 0");
}
style = ast::return_ref(mut_root, arg);
};
(style, parse_ty(p, false))
}
} else {
let pos = p.get_lo_pos();
(ast::return_val, @spanned(pos, pos, ast::ty_nil))
}
}
fn parse_ty(p: parser, colons_before_params: bool) -> @ast::ty {
let lo = p.get_lo_pos();
let hi = lo;
let t: ast::ty_;
// FIXME: do something with this
if eat_word(p, "bool") {
t = ast::ty_bool;
} else if eat_word(p, "int") {
t = ast::ty_int;
} else if eat_word(p, "uint") {
t = ast::ty_uint;
} else if eat_word(p, "float") {
t = ast::ty_float;
} else if eat_word(p, "str") {
t = ast::ty_str;
} else if eat_word(p, "char") {
t = ast::ty_char;
/*
} else if (eat_word(p, "task")) {
t = ast::ty_task;
*/
} else if eat_word(p, "i8") {
t = ast::ty_machine(ast::ty_i8);
} else if eat_word(p, "i16") {
t = ast::ty_machine(ast::ty_i16);
} else if eat_word(p, "i32") {
t = ast::ty_machine(ast::ty_i32);
} else if eat_word(p, "i64") {
t = ast::ty_machine(ast::ty_i64);
} else if eat_word(p, "u8") {
t = ast::ty_machine(ast::ty_u8);
} else if eat_word(p, "u16") {
t = ast::ty_machine(ast::ty_u16);
} else if eat_word(p, "u32") {
t = ast::ty_machine(ast::ty_u32);
} else if eat_word(p, "u64") {
t = ast::ty_machine(ast::ty_u64);
} else if eat_word(p, "f32") {
t = ast::ty_machine(ast::ty_f32);
} else if eat_word(p, "f64") {
t = ast::ty_machine(ast::ty_f64);
} else if p.peek() == token::LPAREN {
p.bump();
if p.peek() == token::RPAREN {
hi = p.get_hi_pos();
p.bump();
t = ast::ty_nil;
} else {
let ts = [parse_ty(p, false)];
while p.peek() == token::COMMA {
p.bump();
ts += [parse_ty(p, false)];
}
if vec::len(ts) == 1u {
t = ts[0].node;
} else { t = ast::ty_tup(ts); }
hi = p.get_hi_pos();
expect(p, token::RPAREN);
}
} else if p.peek() == token::AT {
p.bump();
let mt = parse_mt(p);
hi = mt.ty.span.hi;
t = ast::ty_box(mt);
} else if p.peek() == token::TILDE {
p.bump();
let mt = parse_mt(p);
hi = mt.ty.span.hi;
t = ast::ty_uniq(mt);
} else if p.peek() == token::BINOP(token::STAR) {
p.bump();
let mt = parse_mt(p);
hi = mt.ty.span.hi;
t = ast::ty_ptr(mt);
} else if p.peek() == token::LBRACE {
let elems =
parse_seq(token::LBRACE, token::RBRACE, some(token::COMMA),
parse_ty_field, p);
hi = elems.span.hi;
t = ast::ty_rec(elems.node);
if p.peek() == token::COLON {
p.bump();
t =
ast::ty_constr(@spanned(lo, hi, t),
parse_type_constraints(p));
}
} else if p.peek() == token::LBRACKET {
expect(p, token::LBRACKET);
t = ast::ty_vec(parse_mt(p));
hi = p.get_hi_pos();
expect(p, token::RBRACKET);
} else if eat_word(p, "fn") {
t = parse_ty_fn(ast::proto_fn, p);
alt t { ast::ty_fn(_, _, out, _, _) { hi = out.span.hi; } }
} else if eat_word(p, "block") {
t = parse_ty_fn(ast::proto_block, p);
alt t { ast::ty_fn(_, _, out, _, _) { hi = out.span.hi; } }
} else if eat_word(p, "iter") {
t = parse_ty_fn(ast::proto_iter, p);
alt t { ast::ty_fn(_, _, out, _, _) { hi = out.span.hi; } }
} else if eat_word(p, "obj") {
t = parse_ty_obj(p, hi);
} else if p.peek() == token::MOD_SEP || is_ident(p.peek()) {
let path = parse_path(p);
t = ast::ty_path(path, p.get_id());
hi = path.span.hi;
} else { p.fatal("expecting type"); }
ret parse_ty_postfix(t, p, colons_before_params);
}
fn parse_arg_mode(p: parser) -> ast::mode {
if eat(p, token::BINOP(token::AND)) {
ret ast::by_mut_ref;
} else if eat(p, token::BINOP(token::MINUS)) {
ret ast::by_move;
} else { ret ast::by_ref; }
}
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 = @spanned(p.get_lo_pos(), p.get_hi_pos(), ast::ty_infer);
ret {mode: m, ty: t, ident: i, id: p.get_id()};
}
fn parse_seq_to_before_gt<@T>(sep: option::t<token::token>,
f: fn(parser) -> T,
p: parser) -> [T] {
let first = true;
let v = [];
while p.peek() != token::GT && p.peek() != token::BINOP(token::LSR) &&
p.peek() != 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>(sep: option::t<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>(sep: option::t<token::token>, f: fn(parser) -> T,
p: parser) -> spanned<[T]> {
let lo = p.get_lo_pos();
expect(p, token::LT);
let result = parse_seq_to_before_gt::<T>(sep, f, p);
let hi = p.get_hi_pos();
expect_gt(p);
ret spanned(lo, hi, result);
}
fn parse_seq_to_end<@T>(ket: token::token, sep: option::t<token::token>,
f: fn(parser) -> T, p: parser) -> [T] {
let val = parse_seq_to_before_end(ket, sep, f, p);
p.bump();
ret val;
}
fn parse_seq_to_before_end<@T>(ket: token::token,
sep: option::t<token::token>,
f: fn(parser) -> T, p: parser) -> [T] {
let first: bool = true;
let v: [T] = [];
while p.peek() != ket {
alt sep {
some(t) { if first { first = false; } else { expect(p, t); } }
_ { }
}
v += [f(p)];
}
ret v;
}
fn parse_seq<@T>(bra: token::token, ket: token::token,
sep: option::t<token::token>, f: fn(parser) -> T, p: parser)
-> spanned<[T]> {
let lo = p.get_lo_pos();
expect(p, bra);
let result = parse_seq_to_before_end::<T>(ket, sep, f, p);
let hi = p.get_hi_pos();
p.bump();
ret spanned(lo, hi, result);
}
fn parse_lit(p: parser) -> ast::lit {
let sp = p.get_span();
let lit: ast::lit_ = ast::lit_nil;
if eat_word(p, "true") {
lit = ast::lit_bool(true);
} else if eat_word(p, "false") {
lit = ast::lit_bool(false);
} else {
alt p.peek() {
token::LIT_INT(i) { p.bump(); lit = ast::lit_int(i); }
token::LIT_UINT(u) { p.bump(); lit = ast::lit_uint(u); }
token::LIT_FLOAT(s) {
p.bump();
lit = ast::lit_float(p.get_str(s));
}
token::LIT_MACH_INT(tm, i) {
p.bump();
lit = ast::lit_mach_int(tm, i);
}
token::LIT_MACH_FLOAT(tm, s) {
p.bump();
lit = ast::lit_mach_float(tm, p.get_str(s));
}
token::LIT_CHAR(c) { p.bump(); lit = ast::lit_char(c); }
token::LIT_STR(s) { p.bump(); lit = ast::lit_str(p.get_str(s)); }
token::LPAREN. {
p.bump();
expect(p, token::RPAREN);
lit = ast::lit_nil;
}
t { unexpected(p, t); }
}
}
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.peek() { token::IDENT(_, false) { true } _ { false } };
}
fn parse_path(p: parser) -> ast::path {
let lo = p.get_lo_pos();
let hi = lo;
let global;
if p.peek() == token::MOD_SEP {
global = true;
p.bump();
} else { global = false; }
let ids: [ast::ident] = [];
while true {
alt p.peek() {
token::IDENT(i, _) {
hi = p.get_hi_pos();
ids += [p.get_str(i)];
hi = p.get_hi_pos();
p.bump();
if p.peek() == token::MOD_SEP && p.look_ahead(1u) != token::LT {
p.bump();
} else { break; }
}
_ { break; }
}
}
ret spanned(lo, hi, {global: global, idents: ids, types: []});
}
fn parse_path_and_ty_param_substs(p: parser) -> ast::path {
let lo = p.get_lo_pos();
let path = parse_path(p);
if p.peek() == token::MOD_SEP {
p.bump();
let seq =
parse_seq_lt_gt(some(token::COMMA), bind parse_ty(_, false), p);
let hi = seq.span.hi;
path =
spanned(lo, hi,
{global: path.node.global,
idents: path.node.idents,
types: seq.node});
}
ret path;
}
fn parse_mutability(p: parser) -> ast::mutability {
if eat_word(p, "mutable") {
if p.peek() == token::QUES { p.bump(); ret ast::maybe_mut; }
ret ast::mut;
}
ret ast::imm;
}
fn parse_field(p: parser, sep: token::token) -> ast::field {
let lo = p.get_lo_pos();
let m = parse_mutability(p);
let i = parse_ident(p);
expect(p, sep);
let e = parse_expr(p);
ret spanned(lo, e.span.hi, {mut: 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 parse_bottom_expr(p: parser) -> @ast::expr {
let lo = p.get_lo_pos();
let hi = p.get_hi_pos();
let ex: ast::expr_;
if p.peek() == token::LPAREN {
p.bump();
if p.peek() == token::RPAREN {
hi = p.get_hi_pos();
p.bump();
let lit = @spanned(lo, hi, ast::lit_nil);
ret mk_expr(p, lo, hi, ast::expr_lit(lit));
}
let es = [parse_expr(p)];
while p.peek() == token::COMMA { p.bump(); es += [parse_expr(p)]; }
hi = p.get_hi_pos();
expect(p, token::RPAREN);
if vec::len(es) == 1u {
ret mk_expr(p, lo, hi, es[0].node);
} else { ret mk_expr(p, lo, hi, ast::expr_tup(es)); }
} else if p.peek() == token::LBRACE {
p.bump();
if 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.peek() != token::RBRACE {
if eat_word(p, "with") { base = some(parse_expr(p)); break; }
expect(p, token::COMMA);
fields += [parse_field(p, token::COLON)];
}
hi = p.get_hi_pos();
expect(p, token::RBRACE);
ex = ast::expr_rec(fields, base);
} else if p.peek() == token::BINOP(token::OR) ||
p.peek() == token::OROR {
ret parse_fn_block_expr(p);
} else {
let blk = parse_block_tail(p, lo, ast::checked);
ret mk_expr(p, blk.span.lo, blk.span.hi, ast::expr_block(blk));
}
} else if eat_word(p, "if") {
ret parse_if_expr(p);
} else if eat_word(p, "for") {
ret parse_for_expr(p);
} else if eat_word(p, "while") {
ret parse_while_expr(p);
} else if eat_word(p, "do") {
ret parse_do_while_expr(p);
} else if eat_word(p, "alt") {
ret parse_alt_expr(p);
/*
} else if (eat_word(p, "spawn")) {
ret parse_spawn_expr(p);
*/
} else if eat_word(p, "fn") {
ret parse_fn_expr(p, ast::proto_fn);
} else if eat_word(p, "block") {
ret parse_fn_expr(p, ast::proto_block);
} else if eat_word(p, "lambda") {
ret parse_fn_expr(p, ast::proto_closure);
} else if eat_word(p, "unchecked") {
expect(p, token::LBRACE);
let blk = parse_block_tail(p, lo, ast::unchecked);
ret mk_expr(p, blk.span.lo, blk.span.hi, ast::expr_block(blk));
} else if p.peek() == token::LBRACKET {
p.bump();
let mut = parse_mutability(p);
let es =
parse_seq_to_end(token::RBRACKET, some(token::COMMA), parse_expr,
p);
ex = ast::expr_vec(es, mut);
} else if p.peek() == 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 mk_mac_expr(p, lo, p.get_hi_pos(), ast::mac_embed_type(ty));
} else if p.peek() == token::POUND_LBRACE {
p.bump();
let blk = ast::mac_embed_block(parse_block_tail(p, lo, ast::checked));
ret mk_mac_expr(p, lo, p.get_hi_pos(), blk);
} else if p.peek() == token::ELLIPSIS {
p.bump();
ret mk_mac_expr(p, lo, p.get_hi_pos(), ast::mac_ellipsis);
} else if eat_word(p, "obj") {
// Anonymous object
// Only make people type () if they're actually adding new fields
let fields: option::t<[ast::anon_obj_field]> = none;
if p.peek() == token::LPAREN {
p.bump();
fields =
some(parse_seq_to_end(token::RPAREN, some(token::COMMA),
parse_anon_obj_field, p));
}
let meths: [@ast::method] = [];
let inner_obj: option::t<@ast::expr> = none;
expect(p, token::LBRACE);
while p.peek() != token::RBRACE {
if eat_word(p, "with") {
inner_obj = some(parse_expr(p));
} else { meths += [parse_method(p)]; }
}
hi = p.get_hi_pos();
expect(p, token::RBRACE);
// fields and methods may be *additional* or *overriding* fields
// and methods if there's a inner_obj, or they may be the *only*
// fields and methods if there's no inner_obj.
// We don't need to pull ".node" out of fields because it's not a
// "spanned".
let ob = {fields: fields, methods: meths, inner_obj: inner_obj};
ex = ast::expr_anon_obj(ob);
} else if eat_word(p, "bind") {
let e = parse_expr_res(p, RESTRICT_NO_CALL_EXPRS);
fn parse_expr_opt(p: parser) -> option::t<@ast::expr> {
alt p.peek() {
token::UNDERSCORE. { p.bump(); ret none; }
_ { ret some(parse_expr(p)); }
}
}
let es =
parse_seq(token::LPAREN, token::RPAREN, some(token::COMMA),
parse_expr_opt, p);
hi = es.span.hi;
ex = ast::expr_bind(e, es.node);
} else if p.peek() == 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.peek()) {
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") {
let e = parse_expr(p);
ex = ast::expr_log(1, e);
hi = e.span.hi;
} else if eat_word(p, "log_err") {
let e = parse_expr(p);
ex = ast::expr_log(0, e);
hi = e.span.hi;
} 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, 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::unchecked, e);
} else if eat_word(p, "ret") {
if can_begin_expr(p.peek()) {
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.get_hi_pos();
} else if eat_word(p, "cont") {
ex = ast::expr_cont;
hi = p.get_hi_pos();
} else if eat_word(p, "put") {
alt p.peek() {
token::SEMI. { ex = ast::expr_put(none); }
_ {
let e = parse_expr(p);
hi = e.span.hi;
ex = ast::expr_put(some(e));
}
}
} 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 eat_word(p, "self") {
expect(p, token::DOT);
// The rest is a call expression.
let f: @ast::expr = parse_self_method(p);
let es =
parse_seq(token::LPAREN, token::RPAREN, some(token::COMMA),
parse_expr, p);
hi = es.span.hi;
ex = ast::expr_call(f, es.node);
} else if p.peek() == token::MOD_SEP ||
is_ident(p.peek()) && !is_word(p, "true") &&
!is_word(p, "false") {
check_bad_word(p);
let pth = parse_path_and_ty_param_substs(p);
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_expr(p, lo, hi, ex);
}
fn parse_syntax_ext(p: parser) -> @ast::expr {
let lo = p.get_lo_pos();
expect(p, token::POUND);
ret parse_syntax_ext_naked(p, lo);
}
fn parse_syntax_ext_naked(p: parser, lo: uint) -> @ast::expr {
let pth = parse_path(p);
if vec::len(pth.node.idents) == 0u {
p.fatal("expected a syntax expander name");
}
//temporary for a backwards-compatible cycle:
let es =
if p.peek() == token::LPAREN {
parse_seq(token::LPAREN, token::RPAREN, some(token::COMMA),
parse_expr, p)
} else {
parse_seq(token::LBRACKET, token::RBRACKET, some(token::COMMA),
parse_expr, p)
};
let hi = es.span.hi;
let e = mk_expr(p, es.span.lo, hi, ast::expr_vec(es.node, ast::imm));
ret mk_mac_expr(p, lo, hi, ast::mac_invoc(pth, e, none));
}
fn parse_self_method(p: parser) -> @ast::expr {
let sp = p.get_span();
let f_name: ast::ident = parse_ident(p);
ret mk_expr(p, sp.lo, sp.hi, ast::expr_self_method(f_name));
}
fn parse_dot_or_call_expr(p: parser) -> @ast::expr {
let b = parse_bottom_expr(p);
if expr_has_value(b) { parse_dot_or_call_expr_with(p, b) }
else { b }
}
fn parse_dot_or_call_expr_with(p: parser, e: @ast::expr) -> @ast::expr {
let lo = e.span.lo;
let hi = e.span.hi;
while true {
alt p.peek() {
token::LPAREN. {
if p.get_restriction() == RESTRICT_NO_CALL_EXPRS {
ret e;
} else {
// Call expr.
let es =
parse_seq(token::LPAREN, token::RPAREN,
some(token::COMMA), parse_expr, p);
hi = es.span.hi;
let nd = ast::expr_call(e, es.node);
e = mk_expr(p, lo, hi, nd);
}
}
token::LBRACKET. {
p.bump();
let ix = parse_expr(p);
hi = ix.span.hi;
expect(p, token::RBRACKET);
e = mk_expr(p, lo, hi, ast::expr_index(e, ix));
}
token::DOT. {
p.bump();
alt p.peek() {
token::IDENT(i, _) {
hi = p.get_hi_pos();
p.bump();
e = mk_expr(p, lo, hi, ast::expr_field(e, p.get_str(i)));
}
t { unexpected(p, t); }
}
}
_ { ret e; }
}
}
ret e;
}
fn parse_prefix_expr(p: parser) -> @ast::expr {
let lo = p.get_lo_pos();
let hi = p.get_hi_pos();
let ex;
alt p.peek() {
token::NOT. {
p.bump();
let e = parse_prefix_expr(p);
hi = e.span.hi;
ex = ast::expr_unary(ast::not, e);
}
token::BINOP(b) {
alt b {
token::MINUS. {
p.bump();
let e = parse_prefix_expr(p);
hi = e.span.hi;
ex = ast::expr_unary(ast::neg, e);
}
token::STAR. {
p.bump();
let e = 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 = 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 = 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_expr(p, lo, hi, ex);
}
fn parse_ternary(p: parser) -> @ast::expr {
let cond_expr = parse_binops(p);
if p.peek() == token::QUES {
p.bump();
let then_expr = parse_expr(p);
expect(p, token::COLON);
let else_expr = parse_expr(p);
ret mk_expr(p, cond_expr.span.lo, else_expr.span.hi,
ast::expr_ternary(cond_expr, then_expr, else_expr));
} else { ret cond_expr; }
}
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 @[{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::sub, 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: 6},
{tok: token::BINOP(token::OR), op: ast::bitor, prec: 6},
// 'as' sits between here with 5
{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 = 5;
const ternary_prec: int = 0;
fn parse_more_binops(p: parser, lhs: @ast::expr, min_prec: int) ->
@ast::expr {
if !expr_has_value(lhs) { ret lhs; }
let peeked = p.peek();
for cur: op_spec in *p.get_prec_table() {
if cur.prec > min_prec && cur.tok == peeked {
p.bump();
let rhs = parse_more_binops(p, parse_prefix_expr(p), cur.prec);
let bin =
mk_expr(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_expr(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.get_lo_pos();
let lhs = parse_ternary(p);
alt p.peek() {
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::sub; }
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; }
}
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::t<@ast::expr>,
lo: uint,
hi: uint} {
let lo = p.get_last_lo_pos();
let cond = parse_expr(p);
let thn = parse_block(p);
let els: option::t<@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;
} else if !option::is_none(thn.node.expr) {
let sp = option::get(thn.node.expr).span;
p.span_fatal(sp, "if without else can not return a value");
}
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));
}
}
fn parse_fn_expr(p: parser, proto: ast::proto) -> @ast::expr {
let lo = p.get_last_lo_pos();
let decl = parse_fn_decl(p, ast::impure_fn, ast::il_normal);
let body = parse_block(p);
let _fn = {decl: decl, proto: proto, body: body};
ret mk_expr(p, lo, body.span.hi, ast::expr_fn(_fn));
}
fn parse_fn_block_expr(p: parser) -> @ast::expr {
let lo = p.get_last_lo_pos();
let decl = parse_fn_block_decl(p);
let body = parse_block_tail(p, lo, ast::checked);
let _fn = {decl: decl, proto: ast::proto_block, body: body};
ret mk_expr(p, lo, body.span.hi, ast::expr_fn(_fn));
}
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.get_last_lo_pos();
let is_each = eat_word(p, "each");
let decl = parse_local(p, false);
expect_word(p, "in");
let seq = parse_expr(p);
let body = parse_block_no_value(p);
let hi = body.span.hi;
if is_each {
ret mk_expr(p, lo, hi, ast::expr_for_each(decl, seq, body));
} else { ret mk_expr(p, lo, hi, ast::expr_for(decl, seq, body)); }
}
fn parse_while_expr(p: parser) -> @ast::expr {
let lo = p.get_last_lo_pos();
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.get_last_lo_pos();
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.get_last_lo_pos();
let discriminant = parse_expr(p);
expect(p, token::LBRACE);
let arms: [ast::arm] = [];
while p.peek() != token::RBRACE {
let pats = parse_pats(p);
let guard = none;
if eat_word(p, "when") { guard = some(parse_expr(p)); }
let blk = parse_block(p);
arms += [{pats: pats, guard: guard, body: blk}];
}
let hi = p.get_hi_pos();
p.bump();
ret mk_expr(p, lo, hi, ast::expr_alt(discriminant, arms));
}
fn parse_expr(p: parser) -> @ast::expr {
ret parse_expr_res(p, UNRESTRICTED);
}
fn parse_expr_res(p: parser, r: restriction) -> @ast::expr {
let old = p.get_restriction();
p.restrict(r);
let e = parse_assign_expr(p);
p.restrict(old);
ret e;
}
fn parse_initializer(p: parser) -> option::t<ast::initializer> {
alt p.peek() {
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.peek() == token::BINOP(token::OR) { p.bump(); } else { break; }
}
ret pats;
}
fn parse_pat(p: parser) -> @ast::pat {
let lo = p.get_lo_pos();
let hi = p.get_hi_pos();
let pat;
alt p.peek() {
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.peek() != token::RBRACE {
if first { first = false; } else { expect(p, token::COMMA); }
if p.peek() == token::UNDERSCORE {
p.bump();
if p.peek() != token::RBRACE {
p.fatal("expecting }, found " +
token::to_str(p.get_reader(), p.peek()));
}
etc = true;
break;
}
let fieldname = parse_ident(p);
let subpat;
if p.peek() == token::COLON {
p.bump();
subpat = parse_pat(p);
} else {
if p.get_bad_expr_words().contains_key(fieldname) {
p.fatal("found " + fieldname + " in binding position");
}
subpat =
@{id: p.get_id(),
node: ast::pat_bind(fieldname),
span: ast_util::mk_sp(lo, hi)};
}
fields += [{ident: fieldname, pat: subpat}];
}
hi = p.get_hi_pos();
p.bump();
pat = ast::pat_rec(fields, etc);
}
token::LPAREN. {
p.bump();
if p.peek() == token::RPAREN {
hi = p.get_hi_pos();
p.bump();
pat =
ast::pat_lit(@{node: ast::lit_nil,
span: ast_util::mk_sp(lo, hi)});
} else {
let fields = [parse_pat(p)];
while p.peek() == token::COMMA {
p.bump();
fields += [parse_pat(p)];
}
if vec::len(fields) == 1u { expect(p, token::COMMA); }
hi = p.get_hi_pos();
expect(p, token::RPAREN);
pat = ast::pat_tup(fields);
}
}
tok {
if !is_ident(tok) || is_word(p, "true") || is_word(p, "false") {
let lit = parse_lit(p);
if eat_word(p, "to") {
let end = parse_lit(p);
hi = end.span.hi;
pat = ast::pat_range(@lit, @end);
} else {
hi = lit.span.hi;
pat = ast::pat_lit(@lit);
}
} else if is_plain_ident(p) &&
alt p.look_ahead(1u) {
token::DOT. | token::LPAREN. | token::LBRACKET. {
false
}
_ { true }
} {
hi = p.get_hi_pos();
pat = ast::pat_bind(parse_value_ident(p));
} else {
let tag_path = parse_path_and_ty_param_substs(p);
hi = tag_path.span.hi;
let args: [@ast::pat];
alt p.peek() {
token::LPAREN. {
let a =
parse_seq(token::LPAREN, token::RPAREN,
some(token::COMMA), parse_pat, p);
args = a.node;
hi = a.span.hi;
}
token::DOT. { args = []; p.bump(); }
_ { expect(p, token::LPAREN); fail; }
}
pat = ast::pat_tag(tag_path, args);
}
}
}
ret @{id: p.get_id(), node: pat, span: ast_util::mk_sp(lo, hi)};
}
fn parse_local(p: parser, allow_init: bool) -> @ast::local {
let lo = p.get_lo_pos();
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.get_last_hi_pos(),
{ty: ty, pat: pat, init: init, id: p.get_id()});
}
fn parse_let(p: parser) -> @ast::decl {
fn parse_let_style(p: parser) -> ast::let_style {
eat(p, token::BINOP(token::AND)) ? ast::let_ref : ast::let_copy
}
let lo = p.get_lo_pos();
let locals = [(parse_let_style(p), parse_local(p, true))];
while eat(p, token::COMMA) {
locals += [(parse_let_style(p), parse_local(p, true))];
}
ret @spanned(lo, p.get_last_hi_pos(), ast::decl_local(locals));
}
fn parse_stmt(p: parser) -> @ast::stmt {
if p.get_file_type() == SOURCE_FILE {
ret parse_source_stmt(p);
} else { ret parse_crate_stmt(p); }
}
fn parse_crate_stmt(p: parser) -> @ast::stmt {
let cdir = parse_crate_directive(p, []);
ret @spanned(cdir.span.lo, cdir.span.hi,
ast::stmt_crate_directive(@cdir));
}
fn parse_source_stmt(p: parser) -> @ast::stmt {
let lo = p.get_lo_pos();
if eat_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) {
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 maybe_item = parse_item(p, item_attrs);
// If we have attributes then we should have an item
if vec::len(item_attrs) > 0u {
alt maybe_item {
some(_) {/* fallthrough */ }
_ { ret p.fatal("expected item"); }
}
}
alt maybe_item {
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. {
// Remainder are line-expr stmts.
let e = parse_expr(p);
ret @spanned(lo, e.span.hi, ast::stmt_expr(e, p.get_id()));
}
_ { p.fatal("expected statement"); }
}
}
}
fn expr_has_value(e: @ast::expr) -> bool {
alt e.node {
ast::expr_if(_, th, els) | ast::expr_if_check(_, th, els) {
if option::is_none(els) { false }
else { !option::is_none(th.node.expr) ||
expr_has_value(option::get(els)) }
}
ast::expr_alt(_, arms) {
let found_expr = false;
for arm in arms {
if !option::is_none(arm.body.node.expr) { found_expr = true; }
}
found_expr
}
ast::expr_block(blk) | ast::expr_while(_, blk) |
ast::expr_for(_, _, blk) | ast::expr_for_each(_, _, blk) |
ast::expr_do_while(blk, _) {
!option::is_none(blk.node.expr)
}
_ { true }
}
}
fn stmt_is_expr(stmt: @ast::stmt) -> bool {
ret alt stmt.node {
ast::stmt_expr(e, _) { expr_has_value(e) }
_ { false }
};
}
fn stmt_to_expr(stmt: @ast::stmt) -> option::t<@ast::expr> {
ret if stmt_is_expr(stmt) {
alt stmt.node {
ast::stmt_expr(e, _) { some(e) }
}
} else { none };
}
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_has_value(e);
}
// We should not be calling this on a cdir.
ast::stmt_crate_directive(cdir) {
fail;
}
}
}
fn parse_block(p: parser) -> ast::blk {
let lo = p.get_lo_pos();
if eat_word(p, "unchecked") {
be parse_block_tail(p, lo, ast::unchecked);
} else {
expect(p, token::LBRACE);
be parse_block_tail(p, lo, ast::checked);
}
}
fn parse_block_no_value(p: parser) -> ast::blk {
let blk = parse_block(p);
if !option::is_none(blk.node.expr) {
let sp = option::get(blk.node.expr).span;
p.span_fatal(sp, "this block must not return a value");
}
ret blk;
}
// 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::check_mode) -> ast::blk {
let stmts: [@ast::stmt] = [];
let expr: option::t<@ast::expr> = none;
while p.peek() != token::RBRACE {
alt p.peek() {
token::SEMI. {
p.bump(); // empty
}
_ {
let stmt = parse_stmt(p);
alt stmt_to_expr(stmt) {
some(e) {
alt p.peek() {
token::SEMI. { p.bump(); stmts += [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.get_reader(), t));
}
stmts += [stmt];
}
}
}
none. {
// Not an expression statement.
stmts += [stmt];
if p.get_file_type() == SOURCE_FILE &&
stmt_ends_with_semi(*stmt) {
expect(p, token::SEMI);
}
}
}
}
}
}
let hi = p.get_hi_pos();
p.bump();
let bloc = {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 k =
alt p.peek() {
token::TILDE. { p.bump(); ast::kind_unique }
token::AT. { p.bump(); ast::kind_shared }
_ { ast::kind_pinned }
};
ret {ident: parse_ident(p), kind: k};
}
fn parse_ty_params(p: parser) -> [ast::ty_param] {
let ty_params: [ast::ty_param] = [];
if p.peek() == token::LT {
p.bump();
ty_params = parse_seq_to_gt(some(token::COMMA), parse_ty_param, p);
}
if p.peek() == token::LT {
ty_params =
parse_seq(token::LT, token::GT, some(token::COMMA),
parse_ty_param, p).node;
}
ret ty_params;
}
fn parse_fn_decl(p: parser, purity: ast::purity, il: ast::inlineness) ->
ast::fn_decl {
let inputs: ast::spanned<[ast::arg]> =
parse_seq(token::LPAREN, token::RPAREN, some(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.peek() == token::COLON {
p.bump();
constrs = parse_constrs(bind parse_ty_constr(inputs.node, _), p);
}
let (ret_style, ret_ty) = parse_ret_ty(p, vec::len(inputs.node));
ret {inputs: inputs.node,
output: ret_ty,
purity: purity,
il: il,
cf: ret_style,
constraints: constrs};
}
fn parse_fn_block_decl(p: parser) -> ast::fn_decl {
let inputs =
if p.peek() == token::OROR {
p.bump();;
[]
} else {
parse_seq(token::BINOP(token::OR), token::BINOP(token::OR),
some(token::COMMA), parse_fn_block_arg, p).node
};
ret {inputs: inputs,
output: @spanned(p.get_lo_pos(), p.get_hi_pos(), ast::ty_infer),
purity: ast::impure_fn,
il: ast::il_normal,
cf: ast::return_val,
constraints: []};
}
fn parse_fn(p: parser, proto: ast::proto, purity: ast::purity,
il: ast::inlineness) -> ast::_fn {
let decl = parse_fn_decl(p, purity, il);
let body = parse_block(p);
ret {decl: decl, proto: proto, body: body};
}
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_or_iter(p: parser, purity: ast::purity, proto: ast::proto,
attrs: [ast::attribute], il: ast::inlineness) ->
@ast::item {
let lo = p.get_last_lo_pos();
let t = parse_fn_header(p);
let f = parse_fn(p, proto, purity, il);
ret mk_item(p, lo, f.body.span.hi, t.ident, ast::item_fn(f, t.tps),
attrs);
}
fn parse_obj_field(p: parser) -> ast::obj_field {
let mut = parse_mutability(p);
let ident = parse_value_ident(p);
expect(p, token::COLON);
let ty = parse_ty(p, false);
ret {mut: mut, ty: ty, ident: ident, id: p.get_id()};
}
fn parse_anon_obj_field(p: parser) -> ast::anon_obj_field {
let mut = parse_mutability(p);
let ident = parse_value_ident(p);
expect(p, token::COLON);
let ty = parse_ty(p, false);
expect(p, token::EQ);
let expr = parse_expr(p);
ret {mut: mut, ty: ty, expr: expr, ident: ident, id: p.get_id()};
}
fn parse_method(p: parser) -> @ast::method {
let lo = p.get_lo_pos();
let proto = parse_proto(p);
let ident = parse_value_ident(p);
let f = parse_fn(p, proto, ast::impure_fn, ast::il_normal);
let meth = {ident: ident, meth: f, id: p.get_id()};
ret @spanned(lo, f.body.span.hi, meth);
}
fn parse_item_obj(p: parser, attrs: [ast::attribute]) -> @ast::item {
let lo = p.get_last_lo_pos();
let ident = parse_value_ident(p);
let ty_params = parse_ty_params(p);
let fields: ast::spanned<[ast::obj_field]> =
parse_seq(token::LPAREN, token::RPAREN, some(token::COMMA),
parse_obj_field, p);
let meths: [@ast::method] = [];
expect(p, token::LBRACE);
while p.peek() != token::RBRACE { meths += [parse_method(p)]; }
let hi = p.get_hi_pos();
expect(p, token::RBRACE);
let ob: ast::_obj = {fields: fields.node, methods: meths};
ret mk_item(p, lo, hi, ident, ast::item_obj(ob, ty_params, p.get_id()),
attrs);
}
fn parse_item_res(p: parser, attrs: [ast::attribute]) -> @ast::item {
let lo = p.get_last_lo_pos();
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::by_ref, ty: t, ident: arg_ident, id: p.get_id()}],
output: @spanned(lo, lo, ast::ty_nil),
purity: ast::impure_fn,
il: ast::il_normal,
cf: ast::return_val,
constraints: []};
let f = {decl: decl, proto: ast::proto_fn, body: dtor};
ret mk_item(p, lo, dtor.span.hi, ident,
ast::item_res(f, p.get_id(), ty_params, p.get_id()), attrs);
}
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 =
if vec::len(first_item_attrs) == 0u { parse_view(p) } else { [] };
let items: [@ast::item] = [];
let initial_attrs = first_item_attrs;
while p.peek() != term {
let attrs = initial_attrs + parse_outer_attributes(p);
initial_attrs = [];
alt parse_item(p, attrs) {
some(i) { items += [i]; }
_ {
p.fatal("expected item but found " +
token::to_str(p.get_reader(), p.peek()));
}
}
}
ret {view_items: view_items, items: items};
}
fn parse_item_const(p: parser, attrs: [ast::attribute]) -> @ast::item {
let lo = p.get_last_lo_pos();
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.get_hi_pos();
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.get_last_lo_pos();
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.get_hi_pos();
expect(p, token::RBRACE);
ret mk_item(p, lo, hi, id, ast::item_mod(m), attrs + inner_attrs.inner);
}
fn parse_item_native_type(p: parser, attrs: [ast::attribute]) ->
@ast::native_item {
let t = parse_type_decl(p);
let hi = p.get_hi_pos();
expect(p, token::SEMI);
ret @{ident: t.ident,
attrs: attrs,
node: ast::native_item_ty,
id: p.get_id(),
span: ast_util::mk_sp(t.lo, hi)};
}
fn parse_item_native_fn(p: parser, attrs: [ast::attribute]) ->
@ast::native_item {
let lo = p.get_last_lo_pos();
let t = parse_fn_header(p);
let decl = parse_fn_decl(p, ast::impure_fn, ast::il_normal);
let link_name = none;
if p.peek() == token::EQ { p.bump(); link_name = some(parse_str(p)); }
let hi = p.get_hi_pos();
expect(p, token::SEMI);
ret @{ident: t.ident,
attrs: attrs,
node: ast::native_item_fn(link_name, decl, t.tps),
id: p.get_id(),
span: ast_util::mk_sp(lo, hi)};
}
fn parse_native_item(p: parser, attrs: [ast::attribute]) ->
@ast::native_item {
if eat_word(p, "type") {
ret parse_item_native_type(p, attrs);
} else if eat_word(p, "fn") {
ret parse_item_native_fn(p, attrs);
} else { unexpected(p, p.peek()); }
}
fn parse_native_mod_items(p: parser, native_name: str, abi: ast::native_abi,
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.peek() != token::RBRACE {
let attrs = initial_attrs + parse_outer_attributes(p);
initial_attrs = [];
items += [parse_native_item(p, attrs)];
}
ret {native_name: native_name,
abi: abi,
view_items: view_items,
items: items};
}
fn parse_item_native_mod(p: parser, attrs: [ast::attribute]) -> @ast::item {
let lo = p.get_last_lo_pos();
let abi = ast::native_abi_cdecl;
if !is_word(p, "mod") {
let t = parse_str(p);
if str::eq(t, "cdecl") {
} else if str::eq(t, "rust") {
abi = ast::native_abi_rust;
} else if str::eq(t, "llvm") {
abi = ast::native_abi_llvm;
} else if str::eq(t, "rust-intrinsic") {
abi = ast::native_abi_rust_intrinsic;
} else if str::eq(t, "x86stdcall") {
abi = ast::native_abi_x86stdcall;
} else if str::eq(t, "c-stack-cdecl") {
abi = ast::native_abi_c_stack_cdecl;
} else {
p.fatal("unsupported abi: " + t);
}
}
expect_word(p, "mod");
let id = parse_ident(p);
let native_name;
if p.peek() == token::EQ {
expect(p, token::EQ);
native_name = parse_str(p);
} else { native_name = id; }
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, native_name, abi, first_item_outer_attrs);
let hi = p.get_hi_pos();
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.get_last_lo_pos();
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.get_hi_pos();
expect(p, token::SEMI);
ret mk_item(p, t.lo, hi, t.ident, ast::item_ty(ty, tps), attrs);
}
fn parse_item_tag(p: parser, attrs: [ast::attribute]) -> @ast::item {
let lo = p.get_last_lo_pos();
let id = parse_ident(p);
let ty_params = parse_ty_params(p);
let variants: [ast::variant] = [];
// Newtype syntax
if p.peek() == token::EQ {
if p.get_bad_expr_words().contains_key(id) {
p.fatal("found " + id + " in tag 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,
args: [{ty: ty, id: p.get_id()}],
id: p.get_id()});
ret mk_item(p, lo, ty.span.hi, id,
ast::item_tag([variant], ty_params), attrs);
}
expect(p, token::LBRACE);
while p.peek() != token::RBRACE {
let tok = p.peek();
alt tok {
token::IDENT(name, _) {
check_bad_word(p);
let vlo = p.get_lo_pos();
p.bump();
let args: [ast::variant_arg] = [];
let vhi = p.get_hi_pos();
alt p.peek() {
token::LPAREN. {
let arg_tys =
parse_seq(token::LPAREN, token::RPAREN,
some(token::COMMA), bind parse_ty(_, false), p);
for ty: @ast::ty in arg_tys.node {
args += [{ty: ty, id: p.get_id()}];
}
vhi = arg_tys.span.hi;
}
_ {/* empty */ }
}
expect(p, token::SEMI);
p.get_id();
let vr = {name: p.get_str(name), args: args, id: p.get_id()};
variants += [spanned(vlo, vhi, vr)];
}
token::RBRACE. {/* empty */ }
_ {
p.fatal("expected name of variant or '}' but found " +
token::to_str(p.get_reader(), tok));
}
}
}
let hi = p.get_hi_pos();
p.bump();
ret mk_item(p, lo, hi, id, ast::item_tag(variants, ty_params), attrs);
}
fn parse_auth(p: parser) -> ast::_auth {
if eat_word(p, "unsafe") {
ret ast::auth_unsafe;
} else { unexpected(p, p.peek()); }
}
fn parse_item(p: parser, attrs: [ast::attribute]) -> option::t<@ast::item> {
if eat_word(p, "const") {
ret some(parse_item_const(p, attrs));
} else if eat_word(p, "inline") {
expect_word(p, "fn");
ret some(parse_item_fn_or_iter(p, ast::impure_fn, ast::proto_fn,
attrs, ast::il_inline));
} else if is_word(p, "fn") && p.look_ahead(1u) != token::LPAREN {
p.bump();
ret some(parse_item_fn_or_iter(p, ast::impure_fn, ast::proto_fn,
attrs, ast::il_normal));
} else if eat_word(p, "pure") {
expect_word(p, "fn");
ret some(parse_item_fn_or_iter(p, ast::pure_fn, ast::proto_fn, attrs,
ast::il_normal));
} else if eat_word(p, "iter") {
ret some(parse_item_fn_or_iter(p, ast::impure_fn, ast::proto_iter,
attrs, ast::il_normal));
} 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, "tag") {
ret some(parse_item_tag(p, attrs));
} else if is_word(p, "obj") && p.look_ahead(1u) != token::LPAREN {
p.bump();
ret some(parse_item_obj(p, attrs));
} else if eat_word(p, "resource") {
ret some(parse_item_res(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::t<either::t<[ast::attribute], @ast::expr>>;
fn parse_outer_attrs_or_ext(p: parser) -> attr_or_ext {
if p.peek() == token::POUND {
let lo = p.get_lo_pos();
p.bump();
if p.peek() == token::LBRACKET {
let first_attr = parse_attribute_naked(p, ast::attr_outer, lo);
ret some(left([first_attr] + parse_outer_attributes(p)));
} else if !(p.peek() == token::LT || p.peek() == token::LBRACKET) {
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.peek() == 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.get_lo_pos();
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.get_hi_pos();
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.peek() == token::POUND {
let attr = parse_attribute(p, ast::attr_inner);
if p.peek() == 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.get_lo_pos();
let ident = parse_ident(p);
alt p.peek() {
token::EQ. {
p.bump();
let lit = parse_lit(p);
let hi = p.get_hi_pos();
ret @spanned(lo, hi, ast::meta_name_value(ident, lit));
}
token::LPAREN. {
let inner_items = parse_meta_seq(p);
let hi = p.get_hi_pos();
ret @spanned(lo, hi, ast::meta_list(ident, inner_items));
}
_ {
let hi = p.get_hi_pos();
ret @spanned(lo, hi, ast::meta_word(ident));
}
}
}
fn parse_meta_seq(p: parser) -> [@ast::meta_item] {
ret parse_seq(token::LPAREN, token::RPAREN, some(token::COMMA),
parse_meta_item, p).node;
}
fn parse_optional_meta(p: parser) -> [@ast::meta_item] {
alt p.peek() { 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_rest_import_name(p: parser, first: ast::ident,
def_ident: option::t<ast::ident>) ->
ast::view_item_ {
let identifiers: [ast::ident] = [first];
let glob: bool = false;
let from_idents = option::none::<[ast::import_ident]>;
while true {
alt p.peek() {
token::SEMI. { break; }
token::MOD_SEP. {
if glob { p.fatal("cannot path into a glob"); }
if option::is_some(from_idents) {
p.fatal("cannot path into import list");
}
p.bump();
}
_ { p.fatal("expecting '::' or ';'"); }
}
alt p.peek() {
token::IDENT(_, _) { identifiers += [parse_ident(p)]; }
//the lexer can't tell the different kinds of stars apart ) :
token::BINOP(token::STAR.) {
glob = true;
p.bump();
}
token::LBRACE. {
fn parse_import_ident(p: parser) -> ast::import_ident {
let lo = p.get_lo_pos();
let ident = parse_ident(p);
let hi = p.get_hi_pos();
ret spanned(lo, hi, {name: ident, id: p.get_id()});
}
let from_idents_ =
parse_seq(token::LBRACE, token::RBRACE, some(token::COMMA),
parse_import_ident, p).node;
if vec::is_empty(from_idents_) {
p.fatal("at least one import is required");
}
from_idents = some(from_idents_);
}
_ {
p.fatal("expecting an identifier, or '*'");
}
}
}
alt def_ident {
some(i) {
if glob { p.fatal("globbed imports can't be renamed"); }
if option::is_some(from_idents) {
p.fatal("can't rename import list");
}
ret ast::view_item_import(i, identifiers, p.get_id());
}
_ {
if glob {
ret ast::view_item_import_glob(identifiers, p.get_id());
} else if option::is_some(from_idents) {
ret ast::view_item_import_from(identifiers,
option::get(from_idents),
p.get_id());
} else {
let len = vec::len(identifiers);
ret ast::view_item_import(identifiers[len - 1u], identifiers,
p.get_id());
}
}
}
}
fn parse_full_import_name(p: parser, def_ident: ast::ident) ->
ast::view_item_ {
alt p.peek() {
token::IDENT(i, _) {
p.bump();
ret parse_rest_import_name(p, p.get_str(i), some(def_ident));
}
_ { p.fatal("expecting an identifier"); }
}
}
fn parse_import(p: parser) -> ast::view_item_ {
alt p.peek() {
token::IDENT(i, _) {
p.bump();
alt p.peek() {
token::EQ. {
p.bump();
ret parse_full_import_name(p, p.get_str(i));
}
_ { ret parse_rest_import_name(p, p.get_str(i), none); }
}
}
_ { p.fatal("expecting an identifier"); }
}
}
fn parse_export(p: parser) -> ast::view_item_ {
let ids =
parse_seq_to_before_end(token::SEMI, option::some(token::COMMA),
parse_ident, p);
ret ast::view_item_export(ids, p.get_id());
}
fn parse_view_item(p: parser) -> @ast::view_item {
let lo = p.get_lo_pos();
let the_item =
if eat_word(p, "use") {
parse_use(p)
} else if eat_word(p, "import") {
parse_import(p)
} else if eat_word(p, "export") { parse_export(p) } else { fail };
let hi = p.get_lo_pos();
expect(p, token::SEMI);
ret @spanned(lo, hi, the_item);
}
fn is_view_item(p: parser) -> bool {
alt p.peek() {
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 parse_view(p: parser) -> [@ast::view_item] {
let items: [@ast::view_item] = [];
while is_view_item(p) { items += [parse_view_item(p)]; }
ret items;
}
fn parse_native_view(p: parser) -> [@ast::view_item] {
let items: [@ast::view_item] = [];
while is_view_item(p) { items += [parse_view_item(p)]; }
ret items;
}
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, 0u, 0u, SOURCE_FILE);
ret parse_crate_mod(p, cfg);
}
fn parse_crate_from_source_str(name: str, source: str, cfg: ast::crate_cfg,
sess: parse_sess) -> @ast::crate {
let ftype = SOURCE_FILE;
let filemap = codemap::new_filemap(name, 0u, 0u);
sess.cm.files += [filemap];
let itr = @interner::mk(str::hash, str::eq);
let rdr = lexer::new_reader(sess.cm, source, filemap, itr);
let p = new_parser(sess, cfg, rdr, ftype);
ret parse_crate_mod(p, cfg);
}
// Parses a source module as a crate
fn parse_crate_mod(p: parser, _cfg: ast::crate_cfg) -> @ast::crate {
let lo = p.get_lo_pos();
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.get_lo_pos(),
{directives: [],
module: m,
attrs: crate_attrs.inner,
config: p.get_cfg()});
}
fn parse_str(p: parser) -> str {
alt p.peek() {
token::LIT_STR(s) { p.bump(); ret p.get_str(s); }
_ { fail; }
}
}
// 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.get_lo_pos();
if expect_mod || is_word(p, "mod") {
expect_word(p, "mod");
let id = parse_ident(p);
let file_opt =
alt p.peek() {
token::EQ. { p.bump(); some(parse_str(p)) }
_ { none }
};
alt p.peek() {
// mod x = "foo.rs";
token::SEMI. {
let hi = p.get_hi_pos();
p.bump();
ret spanned(lo, hi, ast::cdir_src_mod(id, file_opt, 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.get_hi_pos();
expect(p, token::RBRACE);
ret spanned(lo, hi,
ast::cdir_dir_mod(id, file_opt, cdirs, mod_attrs));
}
t { unexpected(p, t); }
}
} else if eat_word(p, "auth") {
let n = parse_path(p);
expect(p, token::EQ);
let a = parse_auth(p);
let hi = p.get_hi_pos();
expect(p, token::SEMI);
ret spanned(lo, hi, ast::cdir_auth(n, a));
} 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.peek() == term {
expect_word(p, "mod");
}
let cdirs: [@ast::crate_directive] = [];
while p.peek() != term {
let cdir = @parse_crate_directive(p, first_outer_attr);
cdirs += [cdir];
}
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, 0u, 0u, CRATE_FILE);
let lo = p.get_lo_pos();
let prefix = std::fs::dirname(p.get_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);
let deps: [str] = [];
let cx =
@{p: p,
mode: eval::mode_parse,
mutable deps: deps,
sess: sess,
mutable chpos: p.get_chpos(),
mutable byte_pos: p.get_byte_pos(),
cfg: p.get_cfg()};
let m = eval::eval_crate_directives_to_mod(cx, cdirs, prefix);
let hi = p.get_hi_pos();
expect(p, token::EOF);
ret @spanned(lo, hi,
{directives: cdirs,
module: m,
attrs: crate_attrs,
config: p.get_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 {
codemap::emit_error(none, "unknown input file type: " + input,
sess.cm);
fail
}
}
//
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// compile-command: "make -k -C $RBUILD 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
// End:
//