# Gweimer/utils library
**URL:** https://forum.xod.io/t/gweimer-utils-library/529
**Category:** Look What I’ve Done
**Created:** [February 22, 2018, 5:02pm UTC](https://forum.xod.io/t/gweimer-utils-library/529 "2018-02-22T17:02:46Z")
**Posts on this page:** 12
**Page:** 1
### Author:  [@gweimer](https://forum.xod.io/u/gweimer)
#### Post date: [February 22, 2018, 5:02pm UTC](https://forum.xod.io/t/gweimer-utils-library/529/1 "2018-02-22T17:02:46Z")
Currently includes nodes to cast number to a HEX string, convert byte to bits, and convert bits to byte.
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### Author:  [@gweimer](https://forum.xod.io/u/gweimer)
#### Post date: [April 9, 2018, 2:30am UTC](https://forum.xod.io/t/gweimer-utils-library/529/2 "2018-04-09T02:30:42Z")
I had added if-else nodes using variadic pins, but accidentally used xod\_bkp node in example instead of actual xod node; that has been fixed now.
Fixed bug in bit/byte nodes and made pin order more intuitive (which probably breaks it for anyone using the old version ☹ ).
Replaced LCD code in examples with watch nodes; watch nodes weren’t working for me earlier, but they do now & are more universally available to all users.
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### Author:  [@triko](https://forum.xod.io/u/triko)
#### Post date: [April 19, 2018, 12:24am UTC](https://forum.xod.io/t/gweimer-utils-library/529/3 "2018-04-19T00:24:13Z")
Hey man I wanna ask if you are able to upload new libraries?
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### Author:  [@gweimer](https://forum.xod.io/u/gweimer)
#### Post date: [April 19, 2018, 2:07am UTC](https://forum.xod.io/t/gweimer-utils-library/529/4 "2018-04-19T02:07:35Z")
-Is there something wrong with the current ones?- I assume this is in reference to another thread where you are not able to publish. I followed up there.
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### Author:  [@gweimer](https://forum.xod.io/u/gweimer)
#### Post date: [May 16, 2018, 10:44pm UTC](https://forum.xod.io/t/gweimer-utils-library/529/5 "2018-05-16T22:44:23Z")
Updated gweimer/utils for XOD v0.20.x. Replaced old defer nodes with new generic. Made if-else-v (variadic) generic. Added missing node descriptions.
Any chance xod/core/if-else will be made a variadic? Down-sides I can think of: 1) F as 1st pin is less intuitive, but needed to allow cond/true grouping for variadic pins; 2) Returns value for last True instead of the 1st True, which is not very intuitive for experienced programmers.
Any reason why xod/core/buffer isn’t a generic? Seems buffering strings might be useful and there is no reason to prevent buffering of true/false, etc. I was going to make queue-buffer generic, but it depends on buffer, so it doesn’t make sense at this point…
gweimer/utils now has:
- bits-to-byte
- byte-to-bits
- cast-number-to-hex-string
- hex-to-number (hex -\> decimal conversion)
- if-else-v (variadic if-else)
- queue-buffer (building block for fixed-length queue)
- running-avg (Avg for last number of values; built on queue-buffer)
- utils-example-\* showing examples (and providing tests) for each of the above nodes.
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### Author:  [@nkrkv](https://forum.xod.io/u/nkrkv)
#### Post date: [May 17, 2018, 3:45pm UTC](https://forum.xod.io/t/gweimer-utils-library/529/6 "2018-05-17T15:45:19Z")
Cool! Thank you for sharing!
> [@gweimer](#):
>
> Any chance xod/core/if-else will be made a variadic?
It is somewhat counter-intuitive, let’s leave it as is. However, your version is useful. Maybe the conflict could be solved just by choosing a better metaphor/name for the node?
> [@gweimer](#):
>
> Any reason why xod/core/buffer isn’t a generic?
No real reason. Going to make it generic eventually for plain types. PR’s are welcome 😉
Strings, however, is a more complicated story. The maximal size of an upstream string is unknown at compile time (yet), so `buffer(string)` will not be able to preallocate a static buffer to store snapshots. Only dynamic allocation is possible currently, which is a bad practice on microcontrollers since it could lead to serious heap memory fragmentation, and consequently to stack-heap collision, and MCU hang (in the best case). I’d like to stay away from buffering strings for now.
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### Author:  [@gweimer](https://forum.xod.io/u/gweimer)
#### Post date: [May 17, 2018, 5:07pm UTC](https://forum.xod.io/t/gweimer-utils-library/529/7 "2018-05-17T17:07:39Z")
> [@nkrkv](#):
>
> [make if-else variadic] It is somewhat counter-intuitive, let’s leave it as is. However, your version is useful. Maybe the conflict could be solved just by choosing a better metaphor/name for the node?
Thought of that, but not coming up with any good ideas. “Case” isn’t really a good match either. “Select” is close, but pulse/cond pins would conflict with no clear resolution. Maybe “case” is the best option with DFLT pin and COND/VAL variadics, but it will still return last match, not 1st… I can’t think of a way to fix that without extra pins for internal-use-only to pass status info down the cascade.
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### Author:  [@nkrkv](https://forum.xod.io/u/nkrkv)
#### Post date: [May 17, 2018, 5:36pm UTC](https://forum.xod.io/t/gweimer-utils-library/529/8 "2018-05-17T17:36:29Z")
Maybe something like override / chain / squash? I am thinking of it as of process which takes an initial value (SEED or INIT) and then applies a series of overrides for the accumulated value from left to right
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### Author:  [@gweimer](https://forum.xod.io/u/gweimer)
#### Post date: [May 18, 2018, 12:50am UTC](https://forum.xod.io/t/gweimer-utils-library/529/9 "2018-05-18T00:50:11Z")
Of those, I like override best. Chain is pretty vague and squash implies making something smaller… DFLT and (COND/VAL) would still make sense for override.
“Return DFLT if all COND are false, else override DFLT with VAL associated with right-most COND that is true. A variadic version of if-else with quirky side-affects.”
Hmm…I just realized: if you use F (T/COND), you end up with variadic if-else with all the pins in reverse order… If you read pins from right-to-left, you return T value for 1st True COND, else default to F. Still not “intuitively obvious” since it is reversed, but at least easier to explain… You could keep static if-else and call this if-nested (or if-variadic, or…)
If there were a way to reverse the display order of pins, we would have an easy fix…(but it would put variadic pins 1st).
Another idea that might help is to have a way to process variadic pins in reverse order. If we tried to implement a case node, we would want KEY specified 1st, then return 1st match for any variadic (Match/VAL) pair; default processing order would return last match instead of 1st match (same issue we have with variadic if-else).
Both these “reversing” ideas are just cosmetic to be able to make nodes more intuitive. If we could make reverse-processing of variadic pins conditional at run-time, it might provide a way to implement push/pop stack in a variadic node, but that would not be just a cosmetic change (and might not be practical anyway; how would you deal with wires/pins for both directions? My brain is refusing to work on that now…implementing the grouping of queue-buffers in gweimer/utils/utils-example-queue as a variadic node would be a good test. gweimer/utils/running-avg gives an example that works when only push is needed.)
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### Author:  [@gweimer](https://forum.xod.io/u/gweimer)
#### Post date: [May 22, 2018, 7:19pm UTC](https://forum.xod.io/t/gweimer-utils-library/529/10 "2018-05-22T19:19:50Z")
if-else-v now works with generic data types, but requires at least XOD v0.20.3
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### Author:  [@gweimer](https://forum.xod.io/u/gweimer)
#### Post date: [January 24, 2019, 2:56pm UTC](https://forum.xod.io/t/gweimer-utils-library/529/11 "2019-01-24T14:56:11Z")
Back when data type “Byte” was added, gweimer/utils/byte-to-bits was broken. I finally got around to fixing it by forcing type conversions. Thanks to ceasars for reminding me & even suggesting the solution.
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### Author:  [@gweimer](https://forum.xod.io/u/gweimer)
#### Post date: [March 11, 2019, 2:14am UTC](https://forum.xod.io/t/gweimer-utils-library/529/12 "2019-03-11T02:14:48Z")
Updated for XOD 0.28.0. queue-buffer now uses generic pins for data (but there is an issue resolving pin types if you try to implement a list that supports both push & pop–see utils-example-queue for work-around)