Implement quasi-quoting of multiple syntatic categories.
This commit is contained in:
Kevin Atkinson
parent
35a199c036
commit
6dcd12dc22
@ -8,7 +8,7 @@ import vec;
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import syntax::ast::{crate, expr_, expr_mac, mac_invoc, mac_qq};
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import syntax::fold::*;
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import syntax::ext::base::*;
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import syntax::ext::qquote::expand_qquote;
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import syntax::ext::qquote::{expand_qquote,qq_helper};
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import syntax::parse::parser::parse_expr_from_source_str;
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import codemap::span;
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@ -9,7 +9,7 @@ import syntax::visit::*;
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import syntax::ext::base::*;
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import syntax::ext::build::*;
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import syntax::parse::parser;
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import syntax::parse::parser::{parse_from_source_str};
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import syntax::parse::parser::{parser, parse_from_source_str};
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import syntax::print::*;
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import std::io::*;
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@ -19,12 +19,53 @@ import codemap::span;
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type aq_ctxt = @{lo: uint,
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mutable gather: [{lo: uint, hi: uint, e: @ast::expr}]};
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fn gather_anti_quotes(lo: uint, e: @ast::expr) -> aq_ctxt
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iface qq_helper {
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fn span() -> span;
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fn visit(aq_ctxt, vt<aq_ctxt>);
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fn mk_parse_fn(ext_ctxt,span) -> @ast::expr;
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}
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impl of qq_helper for @ast::expr {
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fn span() -> span {self.span}
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fn visit(cx: aq_ctxt, v: vt<aq_ctxt>) {visit_expr(self, cx, v);}
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fn mk_parse_fn(cx: ext_ctxt, sp: span) -> @ast::expr {
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mk_path(cx, sp, ["syntax", "parse", "parser", "parse_expr"])
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}
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}
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impl of qq_helper for @ast::ty {
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fn span() -> span {self.span}
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fn visit(cx: aq_ctxt, v: vt<aq_ctxt>) {visit_ty(self, cx, v);}
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fn mk_parse_fn(cx: ext_ctxt, sp: span) -> @ast::expr {
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mk_path(cx, sp, ["syntax", "ext", "qquote", "parse_ty"])
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}
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}
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impl of qq_helper for @ast::item {
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fn span() -> span {self.span}
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fn visit(cx: aq_ctxt, v: vt<aq_ctxt>) {visit_item(self, cx, v);}
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fn mk_parse_fn(cx: ext_ctxt, sp: span) -> @ast::expr {
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mk_path(cx, sp, ["syntax", "ext", "qquote", "parse_item"])
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}
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}
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impl of qq_helper for @ast::stmt {
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fn span() -> span {self.span}
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fn visit(cx: aq_ctxt, v: vt<aq_ctxt>) {visit_stmt(self, cx, v);}
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fn mk_parse_fn(cx: ext_ctxt, sp: span) -> @ast::expr {
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mk_path(cx, sp, ["syntax", "ext", "qquote", "parse_stmt"])
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}
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}
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impl of qq_helper for @ast::pat {
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fn span() -> span {self.span}
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fn visit(cx: aq_ctxt, v: vt<aq_ctxt>) {visit_pat(self, cx, v);}
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fn mk_parse_fn(cx: ext_ctxt, sp: span) -> @ast::expr {
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mk_path(cx, sp, ["syntax", "parse", "parser", "parse_pat"])
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}
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}
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fn gather_anti_quotes<N: qq_helper>(lo: uint, node: N) -> aq_ctxt
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{
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let v = @{visit_expr: visit_expr_aq
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with *default_visitor()};
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let cx = @{lo:lo, mutable gather: []};
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visit_expr_aq(e, cx, mk_vt(v));
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node.visit(cx, mk_vt(v));
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ret cx;
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}
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@ -43,31 +84,78 @@ fn is_space(c: char) -> bool {
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syntax::parse::lexer::is_whitespace(c)
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}
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fn expand_ast(ecx: ext_ctxt, _sp: span, _arg:
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ast::mac_arg, body: ast::mac_body)
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fn expand_ast(ecx: ext_ctxt, _sp: span,
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arg: ast::mac_arg, body: ast::mac_body)
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-> @ast::expr
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{
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let what = "expr";
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option::may(arg) {|arg|
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let args: [@ast::expr] =
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alt arg.node {
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ast::expr_vec(elts, _) { elts }
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_ {
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ecx.span_fatal
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(_sp, "#ast requires arguments of the form `[...]`.")
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}
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};
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if vec::len::<@ast::expr>(args) != 1u {
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ecx.span_fatal(_sp, "#ast requires exactly one arg");
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}
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alt (args[0].node) {
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ast::expr_path(@{node: {idents: id, _},_}) if vec::len(id) == 1u
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{what = id[0]}
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_ {ecx.span_fatal(args[0].span, "expected an identifier");}
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}
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}
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let body = get_mac_body(ecx,_sp,body);
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let cm = ecx.session().parse_sess.cm;
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let str = @codemap::span_to_snippet(body.span, cm);
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let (fname, ss) = codemap::get_substr_info(cm,
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body.span.lo, body.span.hi);
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let {node: e, _} = parse_from_source_str(parser::parse_expr,
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fname, some(ss), str,
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ecx.session().opts.cfg,
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ecx.session().parse_sess);
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ret expand_qquote(ecx, e.span, some(*str), e);
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fn finish<T: qq_helper>(ecx: ext_ctxt, body: ast::mac_body_,
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f: fn (p: parser) -> T)
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-> @ast::expr
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{
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let cm = ecx.session().parse_sess.cm;
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let str = @codemap::span_to_snippet(body.span, cm);
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let (fname, ss) = codemap::get_substr_info
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(cm, body.span.lo, body.span.hi);
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let node = parse_from_source_str
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(f, fname, some(ss), str,
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ecx.session().opts.cfg, ecx.session().parse_sess);
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ret expand_qquote(ecx, node.span(), some(*str), node);
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}
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ret alt what {
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"expr" {finish(ecx, body, parser::parse_expr)}
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"ty" {finish(ecx, body, parse_ty)}
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"item" {finish(ecx, body, parse_item)}
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"stmt" {finish(ecx, body, parse_stmt)}
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"pat" {finish(ecx, body, parser::parse_pat)}
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_ {ecx.span_fatal(_sp, "unsupported ast type")}
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};
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}
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fn expand_qquote(ecx: ext_ctxt, sp: span, maybe_str: option::t<str>,
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e: @ast::expr)
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fn parse_ty(p: parser) -> @ast::ty {
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parser::parse_ty(p, false)
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}
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fn parse_stmt(p: parser) -> @ast::stmt {
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parser::parse_stmt(p, [])
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}
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fn parse_item(p: parser) -> @ast::item {
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alt (parser::parse_item(p, [])) {
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some(item) {item}
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none {fail; /* FIXME: Error message, somehow */}
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}
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}
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fn expand_qquote<N: qq_helper>
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(ecx: ext_ctxt, sp: span, maybe_str: option::t<str>, node: N)
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-> @ast::expr
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{
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let str = alt(maybe_str) {
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some(s) {s}
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none {codemap::span_to_snippet(sp, ecx.session().parse_sess.cm)}
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};
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let qcx = gather_anti_quotes(sp.lo, e);
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let qcx = gather_anti_quotes(sp.lo, node);
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let cx = qcx;
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let prev = 0u;
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for {lo: lo, _} in cx.gather {
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@ -107,8 +195,10 @@ fn expand_qquote(ecx: ext_ctxt, sp: span, maybe_str: option::t<str>,
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[]);
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let pcall = mk_call(cx,sp,
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["syntax", "parse", "parser",
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"parse_expr_from_source_str"],
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[mk_str(cx,sp, "<anon>"),
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"parse_from_source_str"],
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[node.mk_parse_fn(cx,sp),
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mk_str(cx,sp, "<anon>"),
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mk_path(cx,sp, ["option","none"]),
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mk_unary(cx,sp, ast::box(ast::imm),
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mk_str(cx,sp, str2)),
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mk_access_(cx,sp,
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@ -2548,13 +2548,13 @@ fn parse_from_source_str<T>(f: fn (p: parser) -> T,
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name: str, ss: codemap::file_substr,
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source: @str, cfg: ast::crate_cfg,
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sess: parse_sess)
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-> {node: T, fm: codemap::filemap}
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-> T
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{
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let p = new_parser_from_source_str(sess, cfg, name, ss, source);
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let r = f(p);
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sess.chpos = p.reader.chpos;
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sess.byte_pos = sess.byte_pos + p.reader.pos;
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ret {node: r, fm: option::get(vec::last(sess.cm.files))};
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ret r;
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}
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fn parse_crate_from_source_str(name: str, source: @str, cfg: ast::crate_cfg,
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