Resurrect the 'rules' tool.

This tool is useful for writing shell completion script for tools
expecting a rule name as argument.

The tool was dropped by 34b46f28c.

Fix #1024.

1 files changed, 14 insertions, 0 deletions

diff --git a/src/eval_env.cc b/src/eval_env.cc
index aa3d2b6..e9b6c43 100644
--- a/src/eval_env.cc
+++ b/src/eval_env.cc
@@ -131,3 +131,17 @@ string EvalString::Serialize() const {
   }
   return result;
 }
+
+string EvalString::Unparse() const {
+  string result;
+  for (TokenList::const_iterator i = parsed_.begin();
+       i != parsed_.end(); ++i) {
+    bool special = (i->second == SPECIAL);
+    if (special)
+      result.append("${");
+    result.append(i->first);
+    if (special)
+      result.append("}");
+  }
+  return result;
+}