Tab#to_s returns a one-line summary of the receipt

Library/Homebrew/tab.rb

@@ -104,4 +104,18 @@ class Tab < OpenStruct
   def write
     tabfile.write to_json
   end
+
+  def to_s
+    s = []
+    case poured_from_bottle
+    when true  then s << "Poured from bottle"
+    when false then s << "Built from source"
+    end
+    unless used_options.empty?
+      s << "Installed" if s.empty?
+      s << "with:"
+      s << used_options.to_a.join(", ")
+    end
+    s.join(" ")
+  end
 end