In J8.04, an in-place operation can be vetted before it is executed, and
will have no effect if it fails.
Henry Rich
On 10/4/2016 3:01 PM, Louis de Forcrand wrote:
I second Raul; the behaviour described is very counter-intuitive. Maybe add a
third setting to 9!:53 which copies a at the start of a tacit verb involving in
place operations?
Also, what is the current (j804) behaviour when an in-place ammend fails?
Since there's only one operation, if it fails a shouldn't be modified should it?
If so, copying a at the beginning of a tacit verb containing more than one
in-place operation (IPO) should always be faster than the current
implementation, since copying would only be needed when two or more IPOs take
place.
Louis
On 04 Oct 2016, at 07:15, Raul Miller <rauldmil...@gmail.com> wrote:
When there are many verbs involved, it seems like the relative cost to
make a copy of the original at the start should be minor.
Thanks,
--
Raul
On Mon, Oct 3, 2016 at 10:52 PM, Henry Rich <henryhr...@gmail.com> wrote:
The shape is just the tip of the iceberg. If the verb in question were m},
there would be no way to restore (a).
And in general, many in-place verbs may have executed before the error. The
original (a) may be long gone.
If you foresee this as a problem, you should execute 9!:53(0) to turn off
early assignment.
Henry Rich
On 10/3/2016 10:34 PM, Raul Miller wrote:
There are two reasons to be concerned about the value of a in the error
case.
The minor one is error recovery. This is a simple example, and easy to
understand. What happens, though, when someone uses try./catch. with a
large code base? This issue would not be easy to isolate, nor will it
be easy to understand.
A bigger issue is the one you mentioned here: debugging. When
debugging code which takes a long time to run, you will at times want
to fix the issue and continue, rather than burning the time necessary
to restart from the beginning.
And, also, this seems like it will be hard to explain and at the same
time distract from issues which are more important.
But keep in mind that I am not recommending the (a=:0)](a) mechanism
for this example. I made that suggestion for hypothetical cases.
I am instead recommending that the shape of a be saved somewhere and
that a have its shape set to what it originally was, in the error
case.
Is there some reason why you think that restoring a's shape in the
error case is not a viable approach here?
Thanks,
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