Re: BX dangers

[Robert Holmgren holmgren@xxxxxxxx]

** Reply to note from xywrite@xxxxxxxx Fri, 12 Dec 1997 18:03:16 -0500 (EST)

> In Xy4DOS XPL programs, sometimes BX doesn't work right. I am used to
> it not working right in SEarches and Change Invisibles, but I just
> found out that it can be disastrous in executing a SORT command.

Harry, put a func FF (screen refresh) in front of "BX sortQ2 " and your
problem disappears. There's nothing wrong with BX or SORT. The problem is that
when (only if) your CI/S "Change Invisible/Selected text only" command
changes the size of the DeFined block, the system gets disoriented, & loses
the position of the last byte in the DF block (in this case, thinks it's 4
bytes away from where it really is). When you use "BC sortXC ", a screen
refresh is automatically performed that readjusts the DF size; with "BX
sortQ2 " there's no refresh (it's as "blind" as the preceding command was
"invisible"). This has been a XyWierdness for a long time; in Xy3 the
cursor would appear one place, while  reported (usually accurately)
that it was really in another (sometimes quite distant) place. It's one of the
reasons func FF was introduced in Xy3+. So programs should use [DO ]FF
liberally.

I suggest that you put "yaron" *after* "Yuen Liang" in your sample sort
text, just to prove that not only is the last entry surviving, but that
it's being sorted too.



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Robert Holmgren
holmgren@xxxxxxxx
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