From 7129883b51206f2b85a582641b40b0eddb236cb2 Mon Sep 17 00:00:00 2001
From: Paul Stansifer <paul.stansifer@gmail.com>
Date: Wed, 1 Aug 2012 14:34:35 -0700
Subject: [PATCH] Allow interpolations of all the nt_*s.

---
 src/libsyntax/ext/tt/macro_rules.rs      |  5 ++-
 src/libsyntax/parse/parser.rs            | 45 ++++++++++++++++++------
 src/test/run-pass/macro-interpolation.rs | 19 ++++++++++
 3 files changed, 57 insertions(+), 12 deletions(-)
 create mode 100644 src/test/run-pass/macro-interpolation.rs

diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index 3c680640a31..28bf79be0d5 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -24,7 +24,10 @@ fn add_new_extension(cx: ext_ctxt, sp: span, name: ident,
             ms(match_nonterminal(@~"lhs",@~"matchers", 0u)),
             ms(match_tok(FAT_ARROW)),
             ms(match_nonterminal(@~"rhs",@~"tt", 1u)),
-        ], some(SEMI), false, 0u, 2u))];
+        ], some(SEMI), false, 0u, 2u)),
+        //to phase into semicolon-termination instead of
+        //semicolon-separation
+        ms(match_seq(~[ms(match_tok(SEMI))], none, true, 2u, 2u))];
 
 
     // Parse the macro_rules! invocation (`none` is for no interpolations):
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 06c0a6edc21..35d7e166306 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -120,23 +120,29 @@ macro_rules! maybe_whole_expr {
 }
 
 macro_rules! maybe_whole {
-    {$p:expr, $constructor:path} => { alt copy $p.token {
-      INTERPOLATED($constructor(x)) { $p.bump(); return x; }
+    {$p:expr, $constructor:ident} => { alt copy $p.token {
+      INTERPOLATED(token::$constructor(x)) { $p.bump(); return x; }
+      _ {}
+    }} ;
+    {deref $p:expr, $constructor:ident} => { alt copy $p.token {
+      INTERPOLATED(token::$constructor(x)) { $p.bump(); return *x; }
+      _ {}
+    }} ;
+    {some $p:expr, $constructor:ident} => { alt copy $p.token {
+      INTERPOLATED(token::$constructor(x)) { $p.bump(); return some(x); }
+      _ {}
+    }} ;
+    {pair_empty $p:expr, $constructor:ident} => { alt copy $p.token {
+      INTERPOLATED(token::$constructor(x)) { $p.bump(); return (~[], x); }
       _ {}
     }}
+
 }
 
+
+
 /* ident is handled by common.rs */
 
-fn dummy() {
-    /* we will need this to bootstrap maybe_whole! */
-    #macro[[#maybe_whole_path[p],
-            alt p.token {
-                INTERPOLATED(token::nt_path(pt)) { p.bump(); return pt; }
-                _ {} }]];
-}
-
-
 class parser {
     let sess: parse_sess;
     let cfg: crate_cfg;
@@ -389,6 +395,8 @@ class parser {
     }
 
     fn parse_ty(colons_before_params: bool) -> @ty {
+        maybe_whole!{self, nt_ty};
+
         let lo = self.span.lo;
 
         alt self.maybe_parse_dollar_mac() {
@@ -610,6 +618,7 @@ class parser {
         parse_ident: fn(parser) -> ident,
         parse_last_ident: fn(parser) -> ident) -> @path {
 
+        maybe_whole!{self, nt_path};
         let lo = self.span.lo;
         let global = self.eat(token::MOD_SEP);
         let mut ids = ~[];
@@ -638,6 +647,7 @@ class parser {
     fn parse_path_with_tps(colons: bool) -> @path {
         debug!{"parse_path_with_tps(colons=%b)", colons};
 
+        maybe_whole!{self, nt_path};
         let lo = self.span.lo;
         let path = self.parse_path_without_tps();
         if colons && !self.eat(token::MOD_SEP) {
@@ -1067,6 +1077,8 @@ class parser {
     }
 
     fn parse_token_tree() -> token_tree {
+        maybe_whole!{deref self, nt_tt};
+
         fn parse_tt_tok(p: parser, delim_ok: bool) -> token_tree {
             alt p.token {
               token::RPAREN | token::RBRACE | token::RBRACKET
@@ -1115,6 +1127,9 @@ class parser {
     }
 
     fn parse_matchers() -> ~[matcher] {
+        // unification of matchers and token_trees would vastly improve
+        // the interpolation of matchers
+        maybe_whole!{self, nt_matchers};
         let name_idx = @mut 0u;
         return self.parse_matcher_subseq(
             name_idx, token::LBRACE, token::RBRACE);
@@ -1601,6 +1616,8 @@ class parser {
     }
 
     fn parse_pat(refutable: bool) -> @pat {
+        maybe_whole!{self, nt_pat};
+
         let lo = self.span.lo;
         let mut hi = self.span.hi;
         let mut pat;
@@ -1830,6 +1847,8 @@ class parser {
     }
 
     fn parse_stmt(+first_item_attrs: ~[attribute]) -> @stmt {
+        maybe_whole!{self, nt_stmt};
+
         fn check_expected_item(p: parser, current_attrs: ~[attribute]) {
             // If we have attributes then we should have an item
             if vec::is_not_empty(current_attrs) {
@@ -1890,6 +1909,8 @@ class parser {
     fn parse_inner_attrs_and_block(parse_attrs: bool)
         -> (~[attribute], blk) {
 
+        maybe_whole!{pair_empty self, nt_block};
+
         fn maybe_parse_inner_attrs_and_next(p: parser, parse_attrs: bool) ->
             {inner: ~[attribute], next: ~[attribute]} {
             if parse_attrs {
@@ -2735,6 +2756,8 @@ class parser {
 
     fn parse_item(+attrs: ~[attribute], vis: visibility)
         -> option<@item> {
+
+        maybe_whole!{some self,nt_item};
         let lo = self.span.lo;
         let (ident, item_, extra_attrs) = if self.eat_keyword(~"const") {
             self.parse_item_const()
diff --git a/src/test/run-pass/macro-interpolation.rs b/src/test/run-pass/macro-interpolation.rs
new file mode 100644
index 00000000000..0f692533eb9
--- /dev/null
+++ b/src/test/run-pass/macro-interpolation.rs
@@ -0,0 +1,19 @@
+
+macro_rules! overly_complicated {
+    {$fnname:ident, $arg:ident, $ty:ty, $body:block, $val:expr, $pat:pat, $res:path} =>
+    {
+        fn $fnname($arg: $ty) -> option<$ty> $body
+        alt $fnname($val) {
+          some($pat) {
+            $res
+          }
+          _ { fail; }
+        }
+    }
+
+}
+fn main() {
+    assert overly_complicated!(f, x, option<uint>, { return some(x); },
+                               some(8u), some(y), y) == 8u
+
+}
\ No newline at end of file