Add bitwise concept #722
Add bitwise concept #722
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Thank you so much @stewartmurrie this is great!
I know how much work goes into adding concepts.
First, purely for your reference, here is my solution to the exercise by only looking at the instructions:
module Secrets exposing (..)
import Bitwise
shiftBack =
Bitwise.shiftRightZfBy
setBits =
Bitwise.or
flipBits =
Bitwise.xor
clearBits mask value =
Bitwise.and (Bitwise.complement mask) valueIt's a little bit on the simple side, but clearBits saves it by not being just an alias 😄 .
I left some small suggestions, and tons of tiny ones (sorry about that, I tend to be super nitpicky for these kinds of PRs), but overall, this is in great shape.
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Hi everyone, it looks like there are still some comments to address, please let me know if you want anything from me. |
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Fantastic work @stewartmurrie, I'm very happy with this :)
I left a few more comments, but I'm approving already.
@ceddlyburge did you want to take a look also?
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| # Instructions | |||
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It's perfect :)
Nice call replacing "your birth year" with the year you met.
Fixes doc bugs
| So, negative numbers will stay negative: | ||
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| ```elm | ||
| Bitwise.shiftRightBy 3 -21 --> -6 |
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This is not what I'm getting from elm repl
> import Bitwise
> import BitwisBitwise.shiftRightBy 3 -21
-3 : Int
also -21 should be 111...101011 according to my calculator app.
| If you want to shift right and fill in with zeros, use `shiftRightZfBy`: | ||
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| ```elm | ||
| Bitwise.shiftRightZfBy 3 -21 --> 1073741818 |
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This is also not what I'm getting, I get
> Bitwise.shiftRightZfBy 3 -21
536870909 : Int
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| -- and = 01000 = 8 | ||
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| ### or |
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I think this should be a level 4 heading
| -- or = 10111 = 23 | ||
| ```` | ||
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| ### Exclusive-or (xor) |
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I think this should be a level 4 heading
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| ````elm | ||
| Bitwise.xor 21 4 --> 17 | ||
| -- 21 = 10101 |
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Might be better to use 20 and 5 here, so that you can see that it works both ways round. ( 0 - 1 and 1 - 0 )
| -- 13 = 01101 | ||
| -- 8 = 01000 | ||
| -- and = 01000 = 8 | ||
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There is an extra blank line here I think
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I left some very minor comments, I'll approve it after that. I don't think they will be difficult to implement or controversial. |
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@stewartmurrie do you still have time to finish this up? Or do you want some help? We are not in any particular rush, but we are also happy to help. I actually realized one more thing this PR is missing, the |
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Yup yup, I'll finish this one out; thanks for checking in :) |
This addresses issue #698 and adds a concept and exercise for bitwise operations. It's based on the Java track's bit-manipulation concept and corresponding Secrets exercise.
I've checked that the exemplar passes the test suite, and the configlet linter is happy (with my stuff at least). Let me know if there's something else I should be doing before this can be merged.