Hi, maybe try using fullRender with defaults (mode=PageMode, lineLength=100, ribbonsPerLine=1.5) and "a" instantiated to "IO()" so that TextDetails can be appended to a file (handle). HTH Christian Johannes Waldmann wrote:

Dear all,

I am writing a long string (several MByte) to a file, with writeFile fname ( render d ) where d :: Text.PrettyPrint.HughesPJ.Doc

I wonder what happens internally (when compiled with ghc -O, if that matters) Will the string be in memory completely before it is actually written?

My d is in fact vcat xs, for a list xs that is generated item by item.

Is there a way to get more efficient behaviour without too much rewriting the program?