Bit syntax integer signedness

[FrankBro]

According to https://erlang.org/doc/programming_examples/bit_syntax.html#defaults

The default signedness for integer is unsigned. Feed on the specifiers to control signedness and make the default unsigned, which leads to unspecified signedness going from integer() to non_neg_integer().

[FrankBro]

Actually I think there's still a problem.

-spec receiver(binary()) -> non_neg_integer().
receiver(B) ->
    <<I>> = B,
    I.

-spec emitter(integer()) -> binary().
emitter(I) ->
    B = <<I>>,
    B.

I think for receiver, it makes sense to require non_neg_integer() but with these changes, emitter errors out because we're building the binary with an integer() instead of a non_neg_integer().

Considering the following:

1> <<A/unsigned>> = <<-1>>.
<<"ÿ">>
2> A.
255
3> <<B/signed>> = <<-1>>.
<<"ÿ">>
4> B.
-1

I think it should allow any sort of integer if it's on RHS, right?

[Zalastax]

From linked article:

The signedness specification can be either signed or unsigned. Notice that signedness only matters for matching.

[codecov-io]

Codecov Report

Merging #283 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #283      +/-   ##
==========================================
+ Coverage   87.68%   87.71%   +0.02%     
==========================================
  Files          18       18              
  Lines        2656     2661       +5     
==========================================
+ Hits         2329     2334       +5     
  Misses        327      327

Impacted Files	Coverage Δ
src/typechecker.erl	90.98% <100%> (+0.02%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update dd02b45...387c966. Read the comment docs.

[FrankBro]

From linked article:

The signedness specification can be either signed or unsigned. Notice that signedness only matters for matching.

Indeed. Fixed with the new commit.

[Zalastax]

Great! Add your examples as test too 😃

[FrankBro]

Should be good now. Requests approvals and I think this is ready to merge.

[zuiderkwast]

Very good! I just have a few style comments. Hope you agree.

[FrankBro]

I agreed with all of them :)

[zuiderkwast]

Awesome! Then I have just one more but just it's a comment about a comment...

[FrankBro]

Should I merge?

[zuiderkwast]

Great! I will squash and merge.

[zuiderkwast]

Or better you merge yourself, you can squash as you want. 👍