Damien writes:
main = do args <- System.getArgs let (m, b) = (read (args!!0), read (args!!1)) let lim :: Int lim = read (args!!2) printstate = args!!3 time1 <- getClockTime let n = 2^b let afact = array (0,n) ((0,1):[(i,i*afact!(i-1)) | i<-[1..n]]) in let (glo, ghi) = gamma_tup lim m b time2 <- getClockTime
gives the Hugs error ERROR "gamma3_7.hs":141 - Syntax error in expression (unexpected `;', possibly due to bad layout)
I tried indenting the last two lines, or just the penulatimate line, but no joy. I've modified my functions to use afact instead of fact, but I'm hoping to have it exist as a global for them, rather than modifying all the function signatures to pass afact down the chain.
Help, please?
Did you supply all of the code for main, or did you chop it off at some point? I'm not exactly sure what you want to do, but I'm guessing that you want the variable afact to be in scope on the right-hand-side of some other functions in your program (gamma_tup, for example). For whatever reason you do not want to pass it explicitly as an argument? Have a read your question properly? If not I'm sorry. So perhaps you want to simulate a global variable. John Hughes has written a nice paper for the Journal of FP that discusses some design considerations for global variables in Haskell (+ extensions). Perhaps you could have a quick read of it. You might find a suitable solution in there. The paper is called: Global Variables in Haskell. You can get a draft from his web-site, http://www.math.chalmers.se/~rjmh/ Also while you are at it, you might want to read the rules for do-notation syntax, this might help with your syntax problems. Section 3.14 of the (revised) Haskell 98 Report: http://research.microsoft.com/Users/simonpj/haskell98-revised/haskell98-repo... Cheers, Bernie.