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import std._io;
import driver.session;
import util.common;
import util.common.new_str_hash;
// FIXME: import std.util.option and use it here.
// import std.util.option;
tag option[T] {
none;
some(T);
}
state type parser =
state obj {
state fn peek() -> token.token;
state fn bump();
io fn err(str s);
fn get_session() -> session.session;
fn get_span() -> common.span;
};
state fn new_parser(session.session sess, str path) -> parser {
state obj stdio_parser(session.session sess,
mutable token.token tok,
mutable common.pos lo,
mutable common.pos hi,
lexer.reader rdr)
{
state fn peek() -> token.token {
log token.to_str(tok);
ret tok;
}
state fn bump() {
tok = lexer.next_token(rdr);
lo = rdr.get_mark_pos();
hi = rdr.get_curr_pos();
}
io fn err(str m) {
auto span = rec(filename = rdr.get_filename(),
lo = lo, hi = hi);
sess.span_err(span, m);
}
fn get_session() -> session.session {
ret sess;
}
fn get_span() -> common.span {
ret rec(filename = rdr.get_filename(),
lo = lo, hi = hi);
}
}
auto srdr = _io.new_stdio_reader(path);
auto rdr = lexer.new_reader(srdr, path);
auto npos = rdr.get_curr_pos();
ret stdio_parser(sess, lexer.next_token(rdr), npos, npos, rdr);
}
state fn expect(parser p, token.token t) {
if (p.peek() == t) {
p.bump();
} else {
let str s = "expecting ";
s += token.to_str(t);
s += ", found ";
s += token.to_str(p.peek());
p.err(s);
}
}
state fn parse_ident(parser p) -> ast.ident {
alt (p.peek()) {
case (token.IDENT(?i)) { p.bump(); ret i; }
case (_) {
p.err("expecting ident");
fail;
}
}
}
state fn parse_ty(parser p) -> ast.ty {
alt (p.peek()) {
case (token.INT) { p.bump(); ret ast.ty_int; }
case (token.UINT) { p.bump(); ret ast.ty_int; }
case (token.STR) { p.bump(); ret ast.ty_str; }
case (token.CHAR) { p.bump(); ret ast.ty_char; }
case (token.MACH(?tm)) { p.bump(); ret ast.ty_machine(tm); }
}
p.err("expecting type");
fail;
}
state fn parse_slot(parser p) -> ast.slot {
let ast.mode m = ast.val;
if (p.peek() == token.BINOP(token.AND)) {
m = ast.alias;
p.bump();
}
let ast.ty t = parse_ty(p);
ret rec(ty=t, mode=m);
}
state fn parse_seq[T](token.token bra,
token.token ket,
option[token.token] sep,
(state fn(parser) -> T) f,
parser p) -> vec[T] {
let bool first = true;
expect(p, bra);
let vec[T] v = vec();
while (p.peek() != ket) {
alt(sep) {
case (some[token.token](?t)) {
if (first) {
first = false;
} else {
expect(p, t);
}
}
case (_) {
}
}
// FIXME: v += f(p) doesn't work at the moment.
let T t = f(p);
v += vec(t);
}
expect(p, ket);
ret v;
}
state fn parse_lit(parser p) -> ast.lit {
alt (p.peek()) {
case (token.LIT_INT(?i)) {
p.bump();
ret ast.lit_int(i);
}
case (token.LIT_UINT(?u)) {
p.bump();
ret ast.lit_uint(u);
}
case (token.LIT_CHAR(?c)) {
p.bump();
ret ast.lit_char(c);
}
case (token.LIT_BOOL(?b)) {
p.bump();
ret ast.lit_bool(b);
}
}
p.err("expected literal");
fail;
}
state fn parse_atom(parser p) -> ast.atom {
ret ast.atom_lit(@parse_lit(p));
}
state fn parse_stmt(parser p) -> @ast.stmt {
alt (p.peek()) {
case (token.LOG) {
p.bump();
auto a = @parse_atom(p);
expect(p, token.SEMI);
ret @ast.stmt_log(a);
}
}
p.err("expected statement");
fail;
}
state fn parse_block(parser p) -> ast.block {
auto f = parse_stmt;
// FIXME: passing parse_stmt as an lval doesn't work at the moment.
ret parse_seq[@ast.stmt](token.LBRACE,
token.RBRACE,
none[token.token],
f, p);
}
state fn parse_slot_ident_pair(parser p) ->
rec(ast.slot slot, ast.ident ident) {
auto s = parse_slot(p);
auto i = parse_ident(p);
ret rec(slot=s, ident=i);
}
state fn parse_fn(parser p) -> tup(ast.ident, ast.item) {
expect(p, token.FN);
auto id = parse_ident(p);
auto pf = parse_slot_ident_pair;
auto inputs =
// FIXME: passing parse_slot_ident_pair as an lval doesn't work at the
// moment.
parse_seq[rec(ast.slot slot, ast.ident ident)]
(token.LPAREN,
token.RPAREN,
some(token.COMMA),
pf, p);
auto output;
if (p.peek() == token.RARROW) {
p.bump();
output = rec(ty=parse_ty(p), mode=ast.val);
} else {
output = rec(ty=ast.ty_nil, mode=ast.val);
}
auto body = parse_block(p);
let ast._fn f = rec(inputs = inputs,
output = output,
body = body);
ret tup(id, ast.item_fn(@f));
}
state fn parse_mod(parser p) -> tup(ast.ident, ast.item) {
expect(p, token.MOD);
auto id = parse_ident(p);
expect(p, token.LBRACE);
let ast._mod m = new_str_hash[ast.item]();
while (p.peek() != token.RBRACE) {
auto i = parse_item(p);
m.insert(i._0, i._1);
}
expect(p, token.RBRACE);
ret tup(id, ast.item_mod(@m));
}
state fn parse_item(parser p) -> tup(ast.ident, ast.item) {
alt (p.peek()) {
case (token.FN) {
ret parse_fn(p);
}
case (token.MOD) {
ret parse_mod(p);
}
}
p.err("expectied item");
fail;
}
state fn parse_crate(parser p) -> ast.crate {
let ast._mod m = new_str_hash[ast.item]();
while (p.peek() != token.EOF) {
auto i = parse_item(p);
m.insert(i._0, i._1);
}
ret rec(module=m);
}
//
// 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 ../.. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
// End:
//
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