Re: XPL programming language

[cld@nospam.acedsl.com (Carl Distefano)]

Reply to note from David Mackinder <davemack@nospam.bigfoot.com> Sat, 28
Jul 2001 22:54:19 +0100

> I was intrigued by some comments Enrique made in his most
> recent contribution to the thread about 'Patchworking with NBW'
> about the problems of translating old XPL utilities into 'the
> new commands language'. 
>
> I have a couple of queries: (1) To what extent does the new
> language depart from the old? (2) Do we have access, courtesy
> of NB NY, to all the requisite information about the
> programming language?

Hard to believe it's 10 years ago, but the more advanced version of
XPL used in NBWin was introduced with Signature in the Fall of 1991. 
(Signature was the immediate predecessor of XyWrite 4 for DOS, which
came out in March 1993.)  The new XPL builds on, rather than departs
from, the XPL used by NB4 and XyWrite 3, with many useful additions
and enhancements.  Some of these are discussed at Mary Bernard's and
Rick Penticoff's site, in the FAQ on programming:

<http://users.moscow.com/rpenticoff/NB/faq/programmingtips.htm>.

Unfortunately, there is no comprehensive guide to XPL available
either in print or online.  The out-of-print booklet published by
XyQuest in the late '80s was rudimentary and incomplete.  A summary
of the 1991 enhancements was included in a printed manual called
"Signature: Making the Transition".  It would be a useful volume for
NB-DOS users making the transition to NBWin, but is, alas, very hard
to find.

Generally speaking, the inability to run "legacy" XPL under NBWin
stems not from changes to the programming language but from
differences between the Windows and DOS programs themselves. 
Usually, however, these differences are manageable.  Naturally, the
more complex the code, the more likely it is to require tweaking.

I've asked Enrique to send me COPY.RN.  If I can identify the source
of its NBWin incompatibilities and suggest some workarounds, I will.

--
Carl Distefano
cld@nospam.acedsl.com
http://www.serve.com/xywwweb/