List wrote: > In an effort to get some level of familiarity with J I am working > through a number of the excellent examples and essays. > > I notice that a number of them have some relatively minor problems, some > of which seem to be platform dependent, some are potentially minor > syntax problems (which are not always so minor if you are not yet good > with the language). > > An example of the latter is in the "Building Applications" lab example. > The line > > DAT=: 'm' fread jpath '~system\examples\data\sales.dat'` > > has a trailing tie which does something I do not understand to DAT - it > does not seem to be a noun or a derived verb anymore. In particular, > $DAT returns a domain error, while DAT by itself returns what appears to > be a boxed array, although trying to unbox it returns a domain error as > well. So I have no clue what sort of object DAT has become. The > statement works correctly, returning an array, if you delete the tie > character. > > So, two questions: First, is this the right forum to report such minor > errors? Second, can anybody explain why that trailing tie character > puts DAT in some odd state?
Yes, this is the correct forum. I don't see the trailing tie in the lab file, which is jpath '~system/extras/labs/system/apps.ijt' Is it possible that you cut and pasted the line, and inadvertently added the tie? Also, if necessary, update to the latest scripts - though I do not recall seeing this before. In general, we don't expect syntax errors in the labs, so please report any you find. There are some obvious platform errors, e.g. if a lab is specifically designed for Windows, then there is no need to report problems running under Linux. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
