On 12 Sep 2012, at 16:04, Eric Velten de Melo wrote:
The behaviour I want to achieve is like this: I want the program when compiled to read from a file, parsing the PGM and at the same time apply transformations to the entries as they are read and write them back to another PGM file.
Such problems are the main motivation for iteratees, conduits, pipes, etc. Every such library contains procedures for doing exactly what you want.
It would be really awesome, though, if it were possible to use a parser written in Parsec with this, in the spirit of avoiding code rewriting and enhancing expressivity and abstraction.
The polyparse library on Hackage is another parser combinator framework that allows lazy incremental parsing. http://hackage.haskell.org/package/polyparse A PDF paper/tutorial is here: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.118.1754&rep=rep1&type=pdf Regards, Malcolm