What's the reason: bug in hugs, bug in HaXml, or my own bad programming techniques?
JE> More an inappropriate use of Hugs -- 10 <customer>s with 999 JE> <contract>s each is a moderately large input file, Almost 6 megs JE> and the Hugs interpreter just isn't designed to work with large JE> inputs. Try compiling the program instead. well, ghc-5.02 seems to dislike something inside XmlLib.hs - it could not find interface defs file for modules IOExts .. I plan to look more deeply into it though. JE> The other issue is that HaXml's XML parser is insufficiently lazy JE> (although the rest of HaXml has very nice strictness properties). For JE> instance, there's no reason why your program shouldn't run in JE> near-constant space, but due to the way the parser is structured it JE> won't begin producing any output until the entire input document has JE> been read. I suspected it, and your comment encouraged me to look more deeply in the code, and yes - it seems that examples like mine simply do not fit in :( JE> Try the identity transform 'main = processXmlWith keep' on your sample JE> document and see if that runs out of heap too. If so, there's not JE> much you can do short of replacing the HaXml parser. I got: runhugs98 +sgt -h5000000 translate_invoices.hs invoice.xml invoice_small.html runhugs: Error occurred {{Gc:4788153}}{{Gc:4619912}}{{Gc:4442164}}{{Gc:4271039}}{{Gc:4122687}}{{Gc:3964107}}{{Gc:3827478}}{{Gc:3680235}}{{Gc:3554593}}{{Gc:3417827}}{{Gc:3286249}}{{Gc:3175771}}{{Gc:3053698}}{{Gc:2936095}}{{Gc:2839042}}{{Gc:2729711}}{{Gc:2624806}}{{Gc:2539770}}{{Gc:2442035}}{{Gc:2347994}}{{Gc:2257773}}{{Gc:4077399}}{{Gc:3715115}} (47153895 reductions, 79953374 cells, 23 garbage collections) {{Gc:3812956}}ERROR - Control stack overflow I tried to put several "observe" statements in the code, but they seem to be ignored in the case of "Control stack overflow". -- Dmitry Astapov //ADEpt E-mail: adept@umc.com.ua GPG KeyID/fprint: F5D7639D/CA36 E6C4 815D 434D 0498 2B08 7867 4860 F5D7 639D