copy all files in a directory ... a little help please?

[bradrn]

@hostilefork

 mysync [
     from: %pages/
     to: %archive/
     <exclude> %dont-copy.txt %dont-copy-either.txt
     <hook> %special.txt (
         print ["Special handling of" name]  ; imagine name filled as %special.txt
         if (last-modified - now) < 12:00 [  ; imagine last-modified also filled in
             return <exclude>
         ]
         print "modified long enough ago, falling through to normal copy"
     )
 ]

Out of curiosity… what would be the simplest way of implementing a dialect like this? I’m still not totally confident I understand how dialects are implemented, and this feels like a nice simple example for me to wrap my head around.