I just shocked to find out that my parser with Spirit-classic is 4x slower than my original ad-hoc parser. I do generate parsetree with pt_parse(). So does my adhoc parser but my adhoc one generates its own custom parse tree. My question are: 1. Does spirit classic with generation of parse tree is known to be slow? 2. Does anyone have ever done perf study and compare Spirit.Classic with Spirit.Qi (assuming to generate custom parse tree in Spirit.Qi)? 3. If the bottleneck is in the Spirit.Classic parse tree generation, has anyone ever done a custom parse tree generation in Spirit.Classic? For now it seems I am hitting a roadblock to use Spirit as performance is my main issue. Your insight is highly appreciated. Thanks HT _________________________________________________________________ Bing brings you maps, menus, and reviews organized in one place. http://www.bing.com/search?q=restaurants&form=MFESRP&publ=WLHMTAG&crea=TEXT_MFESRP_Local_MapsMenu_Resturants_1x1