Rediscover the power of Ant

My last post talks about using groovy template to generate a text file, but I did not realize it can be done in Ant until reading the book- "Ant in action".
Recently when I refactored the ant build script of our comany's build system, I realize I need to learn ant systematically to improve my skills in Ant, so I choose this famous book.
When I learned the "filterset" datatype, I realize I can use that to generate the text file from a template, for example the last example can be written in Ant:

<copy file="test2.template" toFile="test2.txt" overwrite="true">
   <filterset begintoken="%" endtoken="%">
     <filter token="firstname" value="Steve"/>
     <filter token="lastname" value="Zhang"/>
     <filter token="city" value="Toronto"/>
   </filterset>
 </copy>

It is even simpler than Groovy in this case, right?
This example exposes my ignorance level of Ant, I realize that there a still lots of Gems in Ant. As Douglas Crockford said most language contains good parts and bad parts, we need to use only good parts and avoid bad parts, I think what he said also can apply to Ant. So don't easily discard a tool or a language, right now in my case, I love Groovy, I love Gant, they look so cool, but I am not 100% precent for sure Groovy/Gant can fully replace our build script. I have to rely on Ant now.
I start understand the reason why our build script is a kind of ugly: probably we did not fully use the good parts of ant and too much bad parts instead.
So my next step is start reading Ant in Action!