c# - StringTemplate bad performance -

i'm using stringtemplate generate xml files datasets. have more 100,000 records in dataset enumerated loop in template. goes slow (15-20 secs per operation) performance not me.

this example how use st render report:

using (var sw = new stringwriter()) {  st.write(new stringtemplatewriter(sw));  return sw.tostring(); } 

stringtemplatewriter simple writer-class derived istringtemplatewriter without indentation.

by way, in debug screen see lot of such weird message:
"a first chance exception of type 'antlr.noviablealtexception' occurred in stringtemplate.dll"

in deep of debug found parses template recursively , if failed (don't know exactly) throws noviablealtexception exception return deep of stack surface, guess problem in using of try-catch-throw's.

google found nothing useful on this.

main question: how decrease number of exceptions (except rewriting code of st) , improve performance of template rendering?

st parses st templates , groups antlr. if getting syntax errors, template(s) have errors. bets off performance throws exception each one. antlr/st not @ fault here ;) terence