diff --git a/src/libcore/iter-trait.rs b/src/libcore/iter-trait.rs
index 1fae52b4afe..02c32a1bf0d 100644
--- a/src/libcore/iter-trait.rs
+++ b/src/libcore/iter-trait.rs
@@ -35,4 +35,11 @@ fn to_vec() -> ~[A] { iter::to_vec(self) }
 
     fn min() -> A { iter::min(self) }
     fn max() -> A { iter::max(self) }
+
+    fn find(p: fn(A) -> bool) -> option<A> {
+        for self.each |i| {
+            if p(i) { ret some(i) }
+        }
+        ret none;
+    }
 }
diff --git a/src/libsyntax/ext/pipes.rs b/src/libsyntax/ext/pipes.rs
index 5a84d764b9f..ce9b0b0a2cf 100644
--- a/src/libsyntax/ext/pipes.rs
+++ b/src/libsyntax/ext/pipes.rs
@@ -1,17 +1,27 @@
 
 import codemap::span;
 import ext::base::ext_ctxt;
+import ast::tt_delim;
+import parse::lexer::{new_tt_reader, reader, tt_reader_as_reader};
+import parse::parser::{parser, SOURCE_FILE};
+import parse::common::parser_common;
+
+import pipes::parse_proto::proto_parser;
 
 import pipes::pipec::*;
 
-fn expand_proto(cx: ext_ctxt, span: span, id: ast::ident, tt: ast::token_tree)
+fn expand_proto(cx: ext_ctxt, _sp: span, id: ast::ident, tt: ast::token_tree)
     -> @ast::item
 {
-    let proto = protocol(id);
-    let ping = proto.add_state(@"ping", send);
-    let pong = proto.add_state(@"pong", recv);
+    let sess = cx.parse_sess();
+    let cfg = cx.cfg();
+    let body_core = alt tt { tt_delim(tts) { tts } _ {fail}};
+    let tt_rdr = new_tt_reader(cx.parse_sess().span_diagnostic,
+                               cx.parse_sess().interner, body_core);
+    let rdr = tt_rdr as reader;
+    let rust_parser = parser(sess, cfg, rdr.dup(), SOURCE_FILE);
+
+    let proto = rust_parser.parse_proto(id);
 
-    ping.add_message(@"ping", []/~, pong, ~[]);
-    pong.add_message(@"pong", []/~, ping, ~[]);
     proto.compile(cx)
 }
\ No newline at end of file
diff --git a/src/libsyntax/ext/pipes/pipec.rs b/src/libsyntax/ext/pipes/pipec.rs
index 4ad4eef636b..e9dfffcd543 100644
--- a/src/libsyntax/ext/pipes/pipec.rs
+++ b/src/libsyntax/ext/pipes/pipec.rs
@@ -12,7 +12,7 @@
 import pprust::{item_to_str, ty_to_str};
 import ext::base::{mk_ctxt, ext_ctxt};
 import parse;
-import parse::{parse_item_from_source_str};
+import parse::*;
 
 import ast_builder::ast_builder;
 import ast_builder::methods;
@@ -42,7 +42,7 @@ fn reverse() -> direction {
 
 enum message {
     // name, data, current state, next state, next tys
-    message(ident, ~[@ast::ty], state, state, ~[@ast::ty])
+    message(ident, ~[@ast::ty], state, ident, ~[@ast::ty])
 }
 
 impl methods for message {
@@ -89,11 +89,10 @@ fn get_params() -> ~[ast::ty_param] {
     fn gen_send(cx: ext_ctxt) -> @ast::item {
         alt self {
           message(id, tys, this, next, next_tys) {
+            let next = this.proto.get_state(next);
+            assert next_tys.len() == next.ty_params.len();
             let arg_names = tys.mapi(|i, _ty| @("x_" + i.to_str()));
 
-            let args = (arg_names, tys).map(|n, t|
-                                            *n + ": " + t.to_source());
-
             let args_ast = (arg_names, tys).map(
                 |n, t| cx.arg_mode(n, t, ast::by_copy)
             );
@@ -146,9 +145,8 @@ enum state {
 }
 
 impl methods for state {
-    fn add_message(name: ident, +data: ~[@ast::ty], next: state,
+    fn add_message(name: ident, +data: ~[@ast::ty], next: ident,
                    +next_tys: ~[@ast::ty]) {
-        assert next_tys.len() == next.ty_params.len();
         self.messages.push(message(name, data, self, next, next_tys));
     }
 
@@ -179,6 +177,7 @@ fn to_type_decls(cx: ext_ctxt) -> [@ast::item]/~ {
             let message(_, tys, this, next, next_tys) = m;
 
             let name = m.name();
+            let next = this.proto.get_state(next);
             let next_name = next.data_name();
 
             let dir = alt this.dir {
@@ -239,6 +238,11 @@ fn add_state(name: ident, dir: direction) -> state {
         self.add_state_poly(name, dir, ~[])
     }
 
+    /// Get or create a state.
+    fn get_state(name: ident) -> state {
+        self.states.find(|i| i.name == name).get()
+    }
+
     fn add_state_poly(name: ident, dir: direction,
                       +ty_params: ~[ast::ty_param]) -> state {
         let messages = dvec();
@@ -291,7 +295,8 @@ fn compile(cx: ext_ctxt) -> @ast::item {
         let mut client_states = ~[];
         let mut server_states = ~[];
 
-        for self.states.each |s| {
+        // :(
+        for (copy self.states).each |s| {
             items += s.to_type_decls(cx);
 
             client_states += s.to_endpoint_decls(cx, send);
diff --git a/src/libsyntax/syntax.rc b/src/libsyntax/syntax.rc
index 852c815e9fe..7c453cc96e4 100644
--- a/src/libsyntax/syntax.rc
+++ b/src/libsyntax/syntax.rc
@@ -80,7 +80,8 @@ mod ext {
     mod source_util;
 
     mod pipes {
-        mod pipec;
         mod ast_builder;
+        mod parse_proto;
+        mod pipec;
     }
 }