22 Aug
2010
22 Aug
'10
3:17 a.m.
Hello David I've an older version of Hugs installed (Hugs 2003), but the the top line of ReadP.hs has this pragma: {-# OPTIONS -fglasgow-exts -fno-implicit-prelude #-} This means you must to run Hugs with extensions, for the Hugs 2003 that meant running with the command line option / -98 /. For Hugs 2006 this might have changed, though the initial load message should tell you how to enable extensions. Hugs is now rather out-of-date unfortunately, unless you are following a text book that uses it, or a running on a platform were GHC won't work, then the standard advice nowadays is to use GHC. GHC has an interpreter, GHCi, that is very similar to Hugs. Best wishes Stephen