Hello! I have to read a PGM image and transform it into a list of Int values. I read the image (this is an ASCII PGM format) using the readFile function and get a string with the contents of the file. This string contains height and widht of the image at the beginning, and then the pixel values follow. I need to read the height and width, then "cut" them from the string, create an array (or finite map) of Int's (for this I need to know the height and width), and then recursively process the pixel values (i. e. put them into the array). The string is structured as follows: <string> P2 # comment # comment 320<WHITESPACE>243<WHITESPACE>255 130 130 130 130 130 130 130 130 130 130 </string> P2 is the magic number. All lines starting with # are comments and must be ignored. 320 and 243 are width and height. <WHITESPACE> is either a space, or tab, or newline. At the moment, I don't have an idea about how to read width and height. One possible approach would be to convert the string into a list of strings A, using newline as separator. Then, I could create list A' with comments removed. Then, A' can be transformed into a string A'' again. From A'' I know that width is contained between the end of P2 and the first occurrence of whitespace (Char.isSpace). I also know that height is contained between first and second occurrence of white space. I could use some sort of regular expression analogons to access width and height. I have several questions concerning this approach: 1) How can I transform a string into a list of strings, separated by some character (in Java one uses StringTokenizer for this) ? 2) How do the aforementioned "regular expressions' analogons" work in Haskell? Thanks in advance Dmitri Pissarenko -- Dmitri Pissarenko Software Engineer http://dapissarenko.com