Re: Parse Hex into signed number with streamdevice?

["Zimoch, Dirk via Tech-talk" <tech-talk at aps.anl.gov>]

The '-' flag is already used to allow negative hex numbers like "-0x123f"

Dirk

> Am 15.09.2025 um 18:16 schrieb Dmitry Yu. Bolkhovityanov <D.Yu.Bolkhovityanov at inp.nsk.su>:
> 
> Hi Dirk!
> 
> Isn't '+' counter-intuitive?  The word "plus" is usually associated with positive numbers, while negative numbers are associated with '-'.
> 
> Is '-' flag already used for something completely different in input parsing?
> 
> 
> With best regards,
> Dmitry
> 
> 
> 
>> On Mon, 15 Sep 2025, Zimoch, Dirk via Tech-talk wrote:
>> 
>> Hello Eddy
>> 
>> I have implemented your request. See latest commit 5ae38a08.
>> https://urldefense.us/v3/__https://github.com/paulscherrerinstitute/StreamDevice/commit/5ae38a08__;!!G_uCfscf7eWS!cAw9XzrsbzJkeIaTJbCHGITiBrLKBpAF9UPGNJsfAFSd7i_i4yL_A9_NL8SDU87mR-hs6DRqHgTTqdb0ORwuRDxFFQ$
>> 
>> Now, if using the + flag ("%+x" or "%+X"), the value will be interpreted as a
>> signed hex number. That means it will be sign extended if the most significant
>> hex digit is 8 or higher. But if width is given, width characters must have been
>> read:
>> 
>> in "%+x";  sign extends "80", " 9", "0xf", "abcd" but not "0x0f" or "0fed"
>> in "%+4x"; sign extends "abcd" and "0xf0" but not "abc" or "0xf"
>> 
>> Dirk
>> 
>> 
>>> On Mon, 2025-09-15 at 10:28 +0200, Zimoch Dirk wrote:
>>> Hello Eddy
>>> 
>>> Signed %x input is currently not supported by StreamDevice but it is definitely
>>> useful to have. I have to think how to implement it and which flag to use to
>>> signal the switch from normal unsigned %x.
>>> 
>>> Dirk
>>> 
>>> On Mon, 2025-09-15 at 08:04 +0000, Blomley, Edmund (IBPT) via Tech-talk wrote:
>>>> Hey,
>>>> 
>>>> So my device sends me a 4 bit hex which I convert to a float using an ai record and linear conversion with ESLO.
>>>> Let?s ignore the conversion for now, the number needs to be treated as a signed long, so I need to get the 2?s complement:
>>>> 
>>>> 07D0 -> 2000
>>>> F6F5 -> -2315
>>>> 
>>>> Is there a way to do this directly with streamdevice?
>>>> If not, I would need to read in the raw long and convert it myself. What is the best approach to do the conversion with records?
>>>> So far I would do:
>>>> 
>>>> field(CALC, "65535 - A + 1") with A being the raw long.
>>>> Cheers
>>>> eddy
>>>> 
>>