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parsing for the macro system

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This commit is contained in:
Paul Stansifer 2012-06-12 10:59:50 -07:00
parent 650dfe58a3
commit 4f104954a6
8 changed files with 370 additions and 29 deletions
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61
src/libsyntax/parse/parser.rs
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@ -803,10 +803,11 @@ class parser {
} else if self.token == token::POUND
&& self.look_ahead(1u) == token::POUND {
self.bump(); self.bump();
let macname = self.parse_path_without_tps();
let macbody = self.parse_token_tree();
ret pexpr(self.mk_mac_expr(lo, self.span.hi,
mac_invoc_tt(macname, macbody)));
//let macname = self.parse_path_without_tps();
//let macbody = self.parse_token_tree();
//ret pexpr(self.mk_mac_expr(lo, self.span.hi,
// mac_invoc_tt(macname, macbody)));
ret pexpr(self.parse_tt_mac_demo());
} else if self.token == token::POUND
&& self.look_ahead(1u) == token::LT {
self.bump(); self.bump();
@ -1084,6 +1085,58 @@ class parser {
};
}
/* temporary */
fn parse_tt_mac_demo() -> @expr {
let ms = self.parse_seq(token::LBRACE, token::RBRACE,
common::seq_sep_none(),
{|p| p.parse_matcher(@mut 0u)}).node;
let tt = self.parse_token_tree();
alt tt {
tt_delim(tts) {
let rdr = lexer::new_tt_reader(self.reader.span_diag(),
self.reader.interner(), tts)
as reader;
ext::earley_parser::parse(self.sess, self.cfg, rdr, ms);
}
_ { fail; }
}
ret self.mk_expr(0u, 0u, expr_break);
}
fn parse_matcher(name_idx: @mut uint) -> matcher {
let lo = self.span.lo;
let mut sep = none;
if self.eat_keyword("sep") { sep = some(self.token); self.bump(); }
let m = if self.is_keyword("many")||self.is_keyword("at_least_one") {
let zero_ok = self.is_keyword("many");
self.bump();
let ms = (self.parse_seq(token::LPAREN, token::RPAREN,
common::seq_sep_none(),
{|p| p.parse_matcher(name_idx)}).node);
if ms.len() == 0u {
self.fatal("repetition body must be nonempty");
}
mtc_rep(ms, sep, zero_ok)
} else if option::is_some(sep) {
self.fatal("`sep <tok>` must preceed `many` or `at_least_one`");
} else if self.eat_keyword("parse") {
let bound_to = self.parse_ident();
self.expect(token::EQ);
let nt_name = self.parse_ident();
let m = mtc_bb(bound_to, nt_name, *name_idx);
*name_idx += 1u;
m
} else {
let m = mtc_tok(self.token);
self.bump();
m
};
ret spanned(lo, self.span.hi, m);
}
fn parse_prefix_expr() -> pexpr {
let lo = self.span.lo;