Slightly more aggressive about inserting whitespace. Getting frustrated with comments.

Author: graydon

src/comp/pretty/pp.rs

@@ -442,6 +442,16 @@ obj printer(io::writer out,
         }
     }
 
+    fn top() -> print_stack_elt {
+        auto n = vec::len(print_stack);
+        let print_stack_elt top =
+            rec(offset=0, pbreak=broken(inconsistent));;
+        if (n != 0u) {
+            top = print_stack.(n - 1u);
+        }
+        ret top;
+    }
+
     fn print(token x, int L) {
         log #fmt("print %s %d (remaining line space=%d)",
                  tok_str(x), L, space);
@@ -471,12 +481,7 @@ obj printer(io::writer out,
 
             case (BREAK(?b)) {
 
-                auto n = vec::len(print_stack);
-                let print_stack_elt top =
-                    rec(offset=0, pbreak=broken(inconsistent));;
-                if (n != 0u) {
-                    top = print_stack.(n - 1u);
-                }
+                auto top = self.top();
 
                 alt (top.pbreak) {
                     case (fits) {
@@ -552,6 +557,9 @@ fn word(printer p, str wrd) {
 fn huge_word(printer p, str wrd) {
     p.pretty_print(STRING(wrd, 0xffff));
 }
+fn zero_word(printer p, str wrd) {
+    p.pretty_print(STRING(wrd, 0));
+}
 fn spaces(printer p, uint n) { break_offset(p, n, 0); }
 fn zerobreak(printer p) { spaces(p, 0u); }
 fn space(printer p) { spaces(p, 1u); }

src/comp/pretty/pprust.rs

@@ -18,6 +18,7 @@ import pp::cbox;
 import pp::ibox;
 import pp::word;
 import pp::huge_word;
+import pp::zero_word;
 import pp::space;
 import pp::zerobreak;
 import pp::hardbreak;
@@ -1191,14 +1192,21 @@ fn print_comment(&ps s, lexer::cmnt cmnt) {
             word(s.s, cmnt.lines.(0));
             zerobreak(s.s);
         }
-        case (_) {
+        case (lexer::isolated) {
+            hardbreak(s.s);
+            for (str line in cmnt.lines) {
+                zero_word(s.s, line);
+                hardbreak(s.s);
+            }
+        }
+        case (lexer::trailing) {
             if (vec::len(cmnt.lines) == 1u) {
-                word(s.s, cmnt.lines.(0));
+                zero_word(s.s, cmnt.lines.(0));
                 hardbreak(s.s);
             } else {
                 ibox(s.s, 0u);
                 for (str line in cmnt.lines) {
-                    word(s.s, line);
+                    zero_word(s.s, line);
                     hardbreak(s.s);
                 }
                 end(s.s);