syntax: implement ToSource for more things in the quasiquoter.

The last few primitive types were missing.

src/libsyntax/ext/quote.rs

@@ -125,6 +125,26 @@ pub mod rt {
         }
     }
 
+    impl ToSource for () {
+        fn to_source(&self) -> ~str {
+            "()".to_owned()
+        }
+    }
+
+    impl ToSource for bool {
+        fn to_source(&self) -> ~str {
+            let lit = dummy_spanned(ast::LitBool(*self));
+            pprust::lit_to_str(&lit)
+        }
+    }
+
+    impl ToSource for char {
+        fn to_source(&self) -> ~str {
+            let lit = dummy_spanned(ast::LitChar(*self));
+            pprust::lit_to_str(&lit)
+        }
+    }
+
     impl ToSource for int {
         fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::LitInt(*self as i64, ast::TyI));
@@ -227,6 +247,9 @@ pub mod rt {
     impl_to_tokens!(@ast::Expr)
     impl_to_tokens!(ast::Block)
     impl_to_tokens_self!(&'a str)
+    impl_to_tokens!(())
+    impl_to_tokens!(char)
+    impl_to_tokens!(bool)
     impl_to_tokens!(int)
     impl_to_tokens!(i8)
     impl_to_tokens!(i16)

src/test/run-pass-fulldeps/quote-tokens.rs

@@ -26,6 +26,10 @@ fn syntax_extension(cx: &ExtCtxt) {
     let _c: @syntax::ast::Pat = quote_pat!(cx, (x, 1 .. 4, *) );
     let _d: @syntax::ast::Stmt = quote_stmt!(cx, let x = $a; );
     let _e: @syntax::ast::Expr = quote_expr!(cx, match foo { $p_toks => 10 } );
+
+    let _f: @syntax::ast::Expr = quote_expr!(cx, ());
+    let _g: @syntax::ast::Expr = quote_expr!(cx, true);
+    let _h: @syntax::ast::Expr = quote_expr!(cx, 'a');
 }
 
 fn main() {