[comp.sys.handhelds] New IFERR and libraries in general

k36853p@saha.hut.fi (Tapani Otala) (03/12/91)

Couple of questions:

	a) Seems that using the new IFERR posted by Dr. Wickes
	   last week screws up the indentation of RPL programs.
	   Any way to correct this?

	b) Seems that DETACH does not complain when attempting to
	   detach a library _not_ attached to the current directory.
	   Now, is there a _simple_ way to find out into _which_
	   directory a library is attached?

	   I know I could use LIBS to determine whether the library
	   is _not_ attached to the current directory, but its
	   not good enough.  I suppose LIBS used with a directory
	   traversal routine could be used to locate the correct
	   directory, but its a real drag. Plus I am not entirely
	   sure about the uniqueness of the result.

	c) When I PURGE a detached library, the display jerks sideways
	   about one half of the screen. Is this supposed to happen?

	   I have seen this happen with both the new IFERR library and
	   the Strange Case library, the only software libraries I
	   have uploaded so far... the TOOLS directory posted by
	   someone (German/Dutch, I think) didn't convert to a
	   library successfully, anybody know why?

My system is:
	HP 48SX, version D
	in port 1: 128K RAM (true-er... what?  well, HP, anyways :)
 	in port 2: Equation Library Card, or another true-HP 128K RAM

PS. I'm specifically referring to the new IFERR library because I
cannot validate the effects on the old library...


  -- k36853p@saha.hut.fi ------------- Am I not -- A fly like thee? --
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billw@hpcvra.cv.hp.com. (William C Wickes) (03/13/91)

>	a) Seems that using the new IFERR posted by Dr. Wickes
>	   last week screws up the indentation of RPL programs.
>	   Any way to correct this?

The program decompiler built into the 48 doesn't recognize the library IFERR,
which messes up the orderly indentation.  There's no fix for this.

>	b) Seems that DETACH does not complain when attempting to
>	   detach a library _not_ attached to the current directory.
>	   Now, is there a _simple_ way to find out into _which_
>	   directory a library is attached?

The information about which library is attached to a subdirectory is stored
in the directory, not the library.  Hence there is no simple way to
catalog library attachments.

>	   I know I could use LIBS to determine whether the library
>	   is _not_ attached to the current directory, but its
>	   not good enough.  I suppose LIBS used with a directory
>	   traversal routine could be used to locate the correct
>	   directory, but its a real drag. Plus I am not entirely
>	   sure about the uniqueness of the result.

This is the only way to do it; but note that a particular library can be
attached to any number of directories.

>	c) When I PURGE a detached library, the display jerks sideways
>	   about one half of the screen. Is this supposed to happen?

This is normal and harmless.  The library configuration table is stored
at a lower address than the display RAM, so when the table shrinks, the
display jerks while memory is being merged.  I actually "use" this effect
to give me confirmation that the purge has actually happened.

Bill Wickes
HP Corvallis