feat: allow constant and immutable variables to be declared public

[benber86]

What I did

I gave a first try to #2903 after encountering the same issue and discussing it on Discord. This will make it possible to declare immutable and constant variables as public.

This is still a WIP as:

• When creating public getters, I'm lumping the immutable variables along with other state variables as attributes of self, but this should probably be done separately.
• The public getter for constants currently just returns a value, so this will not work for lists or mappings.
• This only allows for the declaration of public(immutable(x)) or public(constant(x)) not immutable(public(x)) or constant(public(x))

How I did it

• Check if public nodes have immutable or constant children to set is_immutable or is_constant accordingly
• Update the getter creation function to handle immutable and constant variables
• Add logic to handle immutable public variables in codegen

How to verify it

• Run tests/parser/syntax/test_public.py

Commit message

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Description for the changelog

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[codecov-commenter]

Codecov Report

Merging #3024 (fab45f2) into master (cb41608) will increase coverage by 0.04%. The diff coverage is 91.42%.

@@            Coverage Diff             @@
##           master    #3024      +/-   ##
==========================================
+ Coverage   88.30%   88.34%   +0.04%     
==========================================
  Files          97       98       +1     
  Lines       10941    11021      +80     
  Branches     2587     2605      +18     
==========================================
+ Hits         9661     9737      +76     
- Misses        831      833       +2     
- Partials      449      451       +2     

Impacted Files	Coverage Δ
vyper/semantics/types/utils.py	90.22% <ø> (ø)
vyper/semantics/types/function.py	87.16% <50.00%> (+0.04%)	:arrow_up:
vyper/codegen/global_context.py	74.07% <75.00%> (-0.72%)	:arrow_down:
vyper/ast/expansion.py	95.00% <100.00%> (+1.06%)	:arrow_up:
vyper/ast/folding.py	92.62% <100.00%> (ø)
vyper/ast/nodes.py	93.22% <100.00%> (+0.04%)	:arrow_up:
vyper/semantics/types/user/interface.py	83.19% <100.00%> (ø)
vyper/semantics/validation/data_positions.py	91.39% <100.00%> (ø)
vyper/semantics/validation/module.py	85.49% <100.00%> (-0.37%)	:arrow_down:
vyper/__init__.py	58.82% <0.00%> (-17.65%)	:arrow_down:
... and 14 more

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[charles-cooper]

by the way, i think that only handling public(immutable(...)) and not immutable(public(...)) is a feature, not a bug

[jarivers082461]

Nice

[charles-cooper]

@benber86 i cleaned up the logic for extracting the public/immutable/constant annotations a little bit

[lgtm-com[bot]]

This pull request introduces 2 alerts when merging 062ffb8f85ae2ab3c3d9b880f4b80654021bb5f8 into 915d430525ab6d83b11d45754b5bc6cc1f8f49f9 - view on LGTM.com

new alerts:

• 1 for Unused local variable
• 1 for Unused import