Mac "Spotlight" shows me several Labs in j602 base libraries have PREPARE-blocks, eg lapack.ijt -- I count some 40 others.
I may be adopting an unpopular stance here, but having only yesterday discovered this facility, I don't like it, and wouldn't commend its use. It's sneaky. And I don't accept it offers any facility that can't be done in an open way, and done better. Lab: lapack.ijt, for example, uses it exclusively to define and execute transient verbs via (3 : 0)'' embedded in the Lab (.ijt) file itself. These verbs look innocuous enough to me, so no blame accrues to the Lab author. But that's not the point. One of the attractions of the Labs facility to the end-user is that it lets the user retain full control of the J session, whilst delivering (on-demand) a series of session input lines, which are faithfully echoed in the IJX session. In other words, it gives the appearance of an invisible teacher leaning over my shoulder and (with my permission, of course!) typing on my keyboard. An illusion, I know, but a comforting one. Really we know that _jlab_ has been loaded in the background... and my! -- it's busy. But this is subtly yet vitally different from having the Lab .ijt file itself executing arbitrary verbs silently on its own authority. It's not a matter of the Labs facility being *unable* to execute such silent verbs, but of assuring the user that it never will. Even if that assurance is implicit, and has no legal substance. Having a PREPARE-block undermines that assurance. It means a Lab can deploy trojans, leaving no record of their having been executed. To detect such code, and discover what it actually does, I need to locate, and peruse, the .ijt file itself. Let me argue for PREPARE *not* to be migrated to j701 in its present form, and for the facility to be "detoxified" in j602. I don't say "withdrawn", because that would break a lot of fine Labs. May I suggest that a PREPARE-block *never* conceals its content from IJX, though perhaps tagging it with: "for system use only, please ignore"? Ian On Tue, Sep 18, 2012 at 10:31 PM, bob therriault <bobtherria...@mac.com> wrote: > Hey everybody, > > In J602 there was a markup Instruction used in labs called PREPARE that would > bracket J commands to allow you to do things behind the scenes when running a > lab file .ijt > > I wonder if this would be an option to have scripts load without having the > learner aware of it. I think that the opengl lab works this way. The actual > lab script is in 602/system/extras/labs/graphics/opengl.ijt and you can see > PREPARE working on the first page. The authoring lab touches on this as I > remember. I am not sure that this facility has transferred to 701 but if it > hasn't it would be nice if that functionality was retained. > > Cheers, bob > > On 2012-09-18, at 1:39 PM, Ric Sherlock wrote: > >> On Wed, Sep 19, 2012 at 7:52 AM, Ian Clark <earthspo...@gmail.com> wrote: >>> >>> Yes, I too would like to combine the whole thing in one single addon. >>> You'll recall the extensive correspondence (17 posts) that followed my >>> original proposal to do just this, and how best to do it? >>> http://www.jsoftware.com/pipermail/programming/2012-September/029259.html >>> The LAPACK way would be to keep separate "loader" scripts in >>> format/zulu and run them like this: >>> load 'format/zulu/lite' >>> load 'format/zulu/bare' >>> ...etc. >>> I can have as many loader scripts as I can fancy a need for. A lot >>> less trouble than releasing and maintaining three separate addons. But >>> I got the hint from the forum that using load/require in this way is >>> "untidy", and that the preferred programmer interface for using any >>> addon is quite simply: >>> load 'category/addon' >> >> I don't think you should see this as untidy. I don't believe that this >> functionality is undesirable or unintended. I suggest you have the >> main/default package named zulu.ijs, but that you include your other >> scripts in the same addon. Then (load 'format/zulu') will work and >> load the script most users will need, but (load 'format/zulu/lite') >> and (load 'format/zulu/bare') will work too if the user needs them. >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
